The GreenHouse Project's Adventures + Lessons in - ELLEN ...

The GreenHouse Project’s Adventures + Lessons inTurning an oldinto a living, breathing, people-centred off ice

The GreenHouse ProjectDorah Lebelo (Executive director)PO Box 32025Braamfontein, 2017South AfricaTel: +27 11 720 3773Fax: +27 11 720 3532Email: dorahl@ghouse.org.zaWebsite: www.greenhouse.org.zaThe teamPotting shed construction- Architects: James Jacobs and Nic Whitcutt of CBS Architects- Quantity Surveyor: Riaz Koor of Koor Dindar- Engineer: Ray Britten of Ray Britten and Associates- Permaculture and water consultants: Thomas Linders and Alan Rosenbergof Lindros WholeEarth Consultants- Builders potting shed: Onzie Mjana, Thulie Manana and the rest of themen and women of Abathandi Construction- Builders willow wall: Onzie Mjana / Mandisa Sidyiyo and team- GreenHouse Project: Vanessa Black, Dorah Lebelo and Yunus DhodaPotting shed documentation- Research: Dorah Lebelo- Text support and funding: Danish Organisation for Renewable Energy (OVE)- Compilation, editing and research: Michelle Nel- Technical drawings, additional research and editing: Vanessa Black- Design and illustration: Ellen Papciak-Rose (www.ellenpapciakrose.com)© GreenHouse Project Printed on paper containing post-industrial waste, bagasse (sugar cane residue)Green building / sustainable constructionThis means to construct durable, reliable and functional structures.Considerations of technical sustainability start with the requirement thatstructures are able to withstand the destructive forces of nature.Beyond this, experts note that product life extension is at the top of a hierarchy of life cycle design strategies.A durable building that lasts, due to competent design, manufacturing and construction procedures, and onethat reliably and continuously fulfils its intended purpose (the technical performance requirement), usuallysaves energy (because manufacturing and construction are energy intensive) and also contributes to lesssolid waste problems. For consumer products, experts have proposed that durability should not be enhancedbeyond the expected useful life, as this can be wasteful. Some theorists have suggested that the real test of abuilding is how it serves its users as they constantly adapt and alter it. He also states that the most significantfailing of contemporary architecture is its focus on style at the expense of function.Extract from: ”The Attainment of Sustainable Construction: A Framework”, by R. C. Hill and P. A. Bowen,accepted for publication in the Journal ”Construction Management and Economics”.Prepared for an Environmental Technology Workshop, The Cape Town 2004 Olympic Bid, 2nd May 1996….)The GreenHouse Project

ContentsForeword.......................................................................................................................2Preface...............................................................................................................................3Chapter 1: Green transformation principles................................................4Chapter 2: The process of planning the GHC – a brief historyand overview .....................................................................................6Chapter 3: The building process................................................9Chapter 4: Materials chosen and avoided...........................................14Chapter 5: Water saving technologies at the GHC...............................22Chapter 6: Energy conservation strategies at the GHC.......................25Chapter 7: Additional challenges........................................................................30Chapter 8: Conclusions ................................................................................................33Chapter 9: Appendix.......................................................................................................35Fact sheet: Summary of the Green Specification usedduring the potting shed conversion.....36Fact sheet: Straw bale construction.....38Fact sheet: Solar cooker.....40Fact sheet: Sod roof.....41Fact sheet: Mini wetland for cleaning greywater.....42Fact sheet: Biolytic system for cleaning greywater.....44Fact sheet: Living willow wall.....46Fact sheet: Storm water drainage system.....48Fact sheet: Asbestos.....50Fact sheet: Timber preservation.....52Contacts ...................................................................................................................................53Donations ...............................................................................................................................53AbbreviationsCBSCommunity Building SupportCoJCity of JohannesburgCSIRCouncil for Scientific and Industrial ResearchELAEarthlife AfricaGHCGreenHouse People’s Environmental CentreGHPGreenHouse ProjectOVEDanish Organisation for Renewable EnergyQSQuantity SurveyorSEEDSustainable Energy for Environment and DevelopmentWSSDWorld Summit on Sustainable DevelopmentAdventures and Lessons in Green Building1

ForewordFour years ago the City of Johannesburg (CoJ)gave the GreenHouse Project (GHP) a huge voteof confidence when it turned us loose on thenorth-western corner of Joubert Park, one ofJohannesburg’s oldest, green public spaces.Johannesburg mayorAmos Masondo plants a yellowwoodtree at the GreenHouse People’sEnvironmental Centre (GHC).We inherited the old Parks Agency maintenance depot, whichincluded an old potting shed and various other brick and prefabbuildings. We needed to start building our vision of a ‘People’sEnvironmental Centre’ by establishing a project office. Our dilemmawas, do we build something new, or do we embrace our greenprinciples of re-using and recycling and renovate an existingbuilding. We chose the latter, by taking the old potting shed‘frog’ and transforming it into a handsome ‘princely’ home for ourorganisation. This is the story of what we learned along the way.We’ve written this for a wide audience – architects, developers,builders, decision-makers in municipalities, homebuilders andrenovators and people without homes. The lessons we havelearned encompass building with care, working positively withpeople and seeing solutions where others see problems.Our aim is to share, teach and inspire. The emphasis has beenon testing and sharing methods with GreenHouse Project staff,project partners, decision-makers and interested members of thepublic. Part of this was through ‘learn and build’ workshops andpart through the documentation of experiences, Glad Files (ourGreen Living and Development files which record what we researchand learn and are available in hard copy and on our website) andthis review document.Learn and build courses, advertised to interested professionals,as well as motivated members of surrounding communities, wereheld as part of the renovation of the potting shed. Topics coveredincluded: straw bale walling, dung floor making and natural painttechniques. People learnt skills in the course of building walls orlaying floors.This book documents two aspectsof the renovation1 How the potting shed was revamped (choice of buildingmaterials, systems, and so on).2 Our experience of living in the building and lessons learned,for example how an existing poor orientation has affected thetemperature, the pros and cons of composting toilets, durabilityof DIY paint, performance of grey water systems and so on.The GreenHouse Project,Johannesburg, November 20042 The GreenHouse Project

The South African NGO theGreenHouse Project (GHP)has established a GreenHousePeople’s Environmental Centre(GHC) in Johannesburg’slargest inner city open space,Joubert Park.PrefaceThe contextThe urban environment in greaterJohannesburg is plagued by a numberof developmental, socio-economic andenvironmental challenges.Despite political will and action, the quality of life ofmany communities has not adequately improved.People long for better services, a healthy andstimulating environment and nutritious food. There isa need for communities themselves to act by accessingresources and information, and exploring moreinnovative methods of doing things.To facilitate this, the South African NGO theGreenHouse Project (GHP) has established aGreenHouse People’s Environmental Centre (GHC)in Johannesburg’s largest inner city open space,Joubert Park. The vision of the GHP is to contributeto transforming Johannesburg into a ‘green’ city byempowering the people of Johannesburg to createand recreate the city in ecologically, socially andeconomically sustainable ways.The project has three mainfocus areas1 Providing a working demonstration of sustainableways to plan, build, landscape, manage energy,water and material resources;2 Supporting organisations working to improve oururban environment, particularly community basedorganisations; and3 The dissemination of information that will enableindividuals in all sectors of our society to sustainablyimprove the quality of life in their communities.The site for the GreenHouse People’s EnvironmentalCentre in Joubert Park was made available to the GHPin January 2002. The first phase included establishing ademonstration food garden, beginning a living ‘willow’boundary wall and the conversion of an existing pottingshed to offices for staff. The Centre was officially openedon the 19 th of August 2002 during the World Summit onSustainable Development (WSSD). The Centre has beenopen to the public since staff moved into the completedoffices in October 2002.The vision of the GHP is to contribute to transforming Johannesburg into a‘green’ city by empowering the people of Johannesburg to create and recreatethe city in ecologically, socially and economically sustainable ways.Adventures and Lessons in Green Building3

Chapter 1:Green transformation principlesBEFOREAFTERBesides cost and quality of materials, you also haveto consider the environmental implications of eachchoice (see our chapter on materials). And in the courseof building, you have to manage the project twiceas carefully to reduce pollution, and water and otherresource wastage.Conservation of resourcesTransforming an existing potting shedinto an office building is a difficult taskin itself, but using green interventionsdemands an even more comprehensiveplanning process. Before we beganon the potting shed we needed toformulate our guiding principles for‘green transformation’:Design and planningA Socio-economic factors: At the GreenHouseProject we have sited our centre in the inner citybecause we want to address urban regenerationand the housing shortage by making informationand demonstrations of appropriate developmentaccessible to many peopleA Land care: The GHP organic gardens show thateven if land is scarce (as it is in the inner city) andthreatened by pollution and neglect, it can still berehabilitated to the point that it can grow food forpeopleA Water pollution control, conservation andefficiency: The GHP has many examples of thesetechnologies on siteA Energy conservation, efficiency and renewablesources: We have ‘green energy’ demonstrations onsite as part of the GHC designA Healthy materials and environments: As far aspossible, we have tried to use non-toxic, natural,sustainably produced resources such as stone,wood, brick, recycled materials and so onA A holistic approach: We’ve tried to embrace careof environment, care of people and care of thesurrounding communityOne of the cornerstones of ‘green’ building is to minimisethe use of resources. The generic resources used inconstruction are energy, water, materials and land.In terms of resource conservation, four mainprinciples were employed for the potting shedrenovation:1. RegenerateHazardous materials including asbestos roofing werereplaced with more benign materials (concrete tiles).Light and ventilation were improved and damperadicated2. Re-useThe building itself was re-used for another purpose.Second hand building materials were used; forexample, existing bricks from the previous building,as well as doors and windows bought fromdemolition yards3. ReduceThe building was designed to reduce resource use.Natural ventilation and insulation were introducedto cut down energy requirements, and greywaterrecycling systems were installed to save water.4. RecycleMaterials removed from the potting shedwere stored for re-use. Steel removed from theexisting building was re-used in security screens.Broken glass from demolished buildings wasused decoratively on the stairs. Rubble from thedemolished buildings on site is continually used tobuild the willow wall.The GHP organic gardens show that evenif land is scarce (as it is in the inner city)and threatened by pollution and neglect,it can still be rehabilitated to the pointthat it can grow food for people.4 The GreenHouse Project

Re-use versus recyclingExamples of re-use include the renovation of existing buildings andrefurbishment for a new purpose. The potting shed revamp is a goodexample of this principle. The principle of re-use should also be bornein mind when new buildings are designed – they should be constructedwith adaptability to meeting changing needs.Where demolition is absolutely necessary, this principle requires theimplementation of salvage. This necessitates the reinstitution of handwrecking and, importantly, planning for disassembly or deconstruction.The aim should be to re-use as much of the structure as possible on another project and to recycle whatcannot be directly re-used. During the potting shed renovation, parts of the original structure were re-used.All materials were carefully disassembled and stored, both for re-use on site or for passing on to other projects.Recycling is different from re-use in that existing items are not used intact but are reduced to raw materialsand used in new products. On the construction site, recycling requires educating workers about recyclingprocedures and instituting on-site sorting of usable waste into bins clearly marked for different types of waste.For example broken window pane glass needs to be stored separately from glass bottles for future collection forrecycling. Excavated sub-soils have also been set aside in large piles so that these can be used in construction.MaterialsSourcing additional materials is also more complex for agreen building. When choosing a material or buildingprocess we have tried to select those that:• Maintain biodiversity; restoring where it has beendisturbed• Minimise consumption of resources especiallynon-renewables• Minimise pollution of soil, air and water• Maximise safety, health and comfort of buildingusersIn assessing how ‘green’ any material is, it is importantto look at the environmental and human impactsthroughout the life cycle of the product.Life cycle stages include:• Resource extraction• Process/manufacturing• Construction• Use and maintenance• Recycling/demolition/disposalPermaculture design principlesThe green interventions were also stronglyinfluenced by Permaculture, a design systemfor creating sustainable human environments.Permaculture deals with the relationship betweenbuildings, infrastructure and plants, created bythe way we place them in the environment. Itemphasises recycling of resources.An exampleof a Permacultureprinciple embodiedin the GreenHouseCentre is the term“Relative location”– the terrace islocated close to thewater tank so thatplants can be watered,fruit trees are plantednext to the terrace toprovide mulch andshade the buildingfrom morning sunin summer, and theterrace is next to thecourtyard to providea pleasant greenbackdrop.Green architectureGreen architecture is not a style, trend or a vernacularand neither is it new. It is a climatically, geographicallyand culturally appropriate way of architecture and building,combining the best of both old and new technology,which has at its core, the principle of respect and caringfor the earth. The issues of environmental responsiveness,resource efficiency, community and cultural sensitivity,healthy and non-polluting environments manifest inmany different ways and often reinforce each other.(Andy Horn (B.Arch), March 1998)Adventures and Lessons in Green Building5

The POTTING SHED from start to finishThe originalpotting shed was asmall, rectangularbuilding. The shedprovided accessto three longglasshouses atright angles to the western wall of the potting shed.The adjoining glasshouses were used for propagatingplants. It was constructed of face brick and had anasbestos roof. Because of its function and being halfsubmerged into the ground, the building sufferedproblems with damp. A wash house and shed, aswell as a carport were located on the east side of thepotting shed.The renovation began with careful demolition ofthe prefabricated buildings to make space for an accessramp and landscaping. An asbestos roof was takenoff the pottingshed, while thewooden rafterswere retained. Thepotting shed ‘shell’was then dividedinto three officesand reception areausing re-usablewooden partitions.The architects wanted to retain the attractive face brick.They also wanted to add windows to bring more lightinto the building.The toilets were built on, as was the kitchen area.The kitchen forms the link between the main office andthe meeting room. The meeting room is a convertedsection of glasshouse.The building itselfdemonstrates soundenvironmental principlesincluding energy and waterefficiency. A built-in solarstove cooks staff lunches,a solar water heater warmswater, rainwater is harvested,greywater from basins iscleaned by biological systems,and two composting toilets have been installed to dealwith human waste at source. Energy is being managedin the building design through the use of celluloseinsulation in the ceiling and reflective glass.Energy was further saved by re-using existingmaterials, thereby saving energy embodied inextraction and manufacture. Where second-handmaterials were not available, small companies andlocal artists were contracted to make elements ofthe building thereby boosting local economies. Theproject is also testing traditional and new alternatives toconventional construction such as the straw bale wallthat has been used to close off the boardroom.The potting shed office was sufficiently completeto be officially opened during the World Summit onSustainable Development (WSSD). Staff moved intothe office after the summit and have been happy intheir new ‘home’ ever since.Where second-hand materials werenot available, small companiesand local artists were contractedto make elements of the buildingthereby boosting local economies.8The GreenHouse Project

Chapter 3:The building processThe potting shed renovation was noordinary building process. Usually contractorswant to finish a building in aslittle time and for as little money as possible.We wanted to build with integrity. Contracts wereawarded to architects, contractors and buildersbased on their social responsibility credentials, theirempowerment potential and their commitment to agreen building process.Our social objectives included the use of locallabour, small businesses, previously disadvantagedpeople, more women, and processes that offered skillsdevelopment for local people.Environmental requirements included conservation ofresources, zero waste, no pollution, and no toxic materials.Broadly, the contractor finally chosenwas a female, emerging contractor.Her appointment therefore challengedconventional race and genderstereotypes. The building processwas to include a substantialempowerment component.Workers were to be taught aboutthe importance of caring for theenvironment, how to behave in anenvironmentally-responsible wayon a building site and how to usecertain green building techniquessuch as mud plastering or dung flooring(these were taught at special ‘learn andbuild’ workshops held in the course of construction).Further, the building process was to be guided bya Green Specification which would spell out ‘green’building practise on site.Selection and appointment ofcontractorsAn emerging woman contractor, Abathandi Projects(Thulie Manana), was appointed to commenceconstruction of Phase one in January 2002. She waschosen from a small group of women contractorsrecommended from the DBSA’s ‘Women inConstruction’ programme. Candidates were interviewedand the architects inspected previous constructionworks. The Bills of Quantity were negotiated betweenAbathandi and our quantity surveyor.CBS Architects chose to go the route of a negotiatedcontract as we had specific social development goalsand a tendering process would not necessarily ensurea high standard of work or that our green requirementswould be met.Later we contracted Onzela Mjana, Thulie’s foreman,and his wife Mandisa to build the ‘willow wall’. We hadbuilt up a trusting relationship with them and theywere committed to our green building goals, includingensuring that half of the construction team would bewomen. We were also under pressure to completethe works in a month before the World Summit onSustainable Development and couldn’t start anelaborate new process. However, the willow wall was amuch simpler construction than the office.The building process was to include asubstantial empowerment component.Workers were to be taught aboutthe importance of caring for theenvironment, how to behave in anenvironmentally-responsible way ona building site and how to use certaingreen building techniques such as mudplastering or dung flooring.Adventures and Lessons in Green Building9

The Green SpecificationThe conversion of the potting shed would yield morethan a building at the end of the process; it would pilotgreen construction at the GHC. To this end the GHPdrew up a Green Specification for the contractor whichdetailed how to manage the site and building process inan environmentally sound way. The Green Specificationwas adapted from one developed by Ninham Shand forthe Cape Town Olympic Bid.It covered many issues including resources used,waste disposal, water use and pollution, preservingsignificant cultural and natural features, soil, hazardousmaterials, noise, air pollution, public safety, informationsharing and labour. It offered a holistic approach tothe environment which places ecological sustainabilitywithin the framework of social justice, equity and abetter quality of life for all. Its purpose was to guidethe contractors’ behaviour on site and through theconstruction process and influence decisions aboutpurchasing of bulk materials based on life cycle ofmaterial prior to construction. (A summary of the GreenSpecifications can be found in the appendix).On the construction site, environmentallysustainable construction requires the development ofoperational procedures for controlling various activitiesincluding emergencies, and the management ofnoise, odour, dust, vibration, chemical and particulateemissions, and solid and sanitary waste duringconstruction operations.Materials from the dismantling of a prefabricatedshed that could be re-used were stored.Not all materials were easy to recycle. Research onthe possible re-use of an old road surface concludedthat asphalt recycling would not be feasible due to areluctance by the industry to re-use asphalt. Asphaltcan either be tar-based and very toxic or bitumenbasedand less toxic. It is likely that asphalt at the GHCis tar-based and should not be re-used where it canleach toxins into buildings or food crops. A letter wassecured permitting the GHP’s asphalt to be dumped atthe municipal dumping site where it may be mined foraggregate in the future.Capacity buildingAs part of the ConstructionManagement Strategy,Vanessa Black andDorah Lebelo facilitatedtwo environmentalawarenessworkshopsfor construction workersto raise awareness aboutthe importance of theenvironment, and howthey could help protectand look after it in theirday-to-day constructionwork on site:13 th February 2002 with18 participants and11 th April 2002 with21 participants.These workshops also helped the project in trying toconvince the contractor and workers to do certain thingsdifferently, as requested in the Green Specification.Second-hand components such as windows anddoors were restored for use in the renovation. Allthe rubble, soils and tar resulting from excavationsfor a garden alongside the building have been piledseparately for later re-use.LessonsAlthough workers had a markedly different attitudeon site after the training, the training was insufficientto get complete buy-in to the idea and discuss thepracticalities of implementing the green spec. Thecontractor was reluctant to give up more time to thetraining and we had a number of cancelled datesbefore we secured the second training time. Thismeant that quite a bit of work had proceeded beforepeople understood why they were being asked towork in a particular way.There was high staff turnover in certain tradesso there were often many new people on site who10The GreenHouse Project

hadn’t had training. Without the background andin the absence of good management it was verydifficult to maintain environmental practices on site.As the contractor floundered more subcontractorswere brought onto site under directmanagement of the architects. Both the GHPand architects were remiss in not acquaintingsub-contractors with our green principles. Whenenvironmental considerations weren’t followed onsite the main contractor blamed sub-contractorsnot under her control for the problems. We also hadsmall but frustrating incidents which highlightedthe need for everyone to understand the principlesbehind the work and not rely on instructions only.For example, we tried to use materials whichwere natural, renewable and healthy in the officeas far as possible and thus timber was chosen tocreate office partitions. The carpenters installing thepartitions, however, decided that the gaps betweenthe boards needed to be closed and stuck plasticpacking tape over all the joins in the middle of thepartitions. The ugly and unhealthy plastic remains tothis day.In future processes we should remedythe above problems by:1 Being in greater control of the training processsuch that no one can work on site without basicenvironmental awareness training. It wouldprobably be better for training responsibility andbudgets to be vested with the architects or GHPand not the contractor.2 Training should be a minimum of one full dayso that there is time to develop buy-in to theidea and then workshop how each trade wouldpractically implement the green spec. It is likelythen that the training provider will need to adaptto flexible training times and more training ofsmaller groups. This has cost implications.3 Workers were concerned that they were not goingto be paid for the time they spent in training. Inthis case training was included in work time forpayment, but this needs to be carefully consideredin future work especially where projects fundedby poverty relief require training. Do we paypeople to be trained and pay the trainingprovider? Environmental and life skills training willbe contentious as many people will not be willingto spend unpaid time on training which is notperceived as contributing to job skills.Despite signing a contract committingto a green construction process, thecontractor’s interest in learning newenvironmental building skills andcompliance with requirements wanedas the building progressed.Green building managementA green builder from Cape Town, Ivan Groenhof, wascontracted in to assist the architects and contractor indrawing up a detailed construction management plan.The GHP, CBS, QS and contractor held weekly sitemeetings in the early stages of construction to reviewand amend this strategy. Further into the process thecontractor didn’t pitch up and the meetings becamepointless.Abathandi required finance for the project with highinterest rates. As the GHP had the construction moneyin the bank we offered to purchase materials directly,to avoid the need for the contractor to have up-frontcapital and to qualify for discounts thus saving costs allround.In time it transpired that even with this financialconcern and workload removed the contractor didnot have adequate skills to manage a contract of thisnature. Soon after starting, the foreman we had beenintroduced to disappeared. A new foreman appointedhalf way through construction improved the situationand his interest in our green ideals was slowly wonover. He continued on site, building the willow wallwith his wife in a new company. Despite signing acontract committing to a green construction process,the contractor’s interest in learning new environmentalbuilding skills and compliance with requirementswaned as the building progressed.To have the buildingcompleted by the Summit,CBS Architects had to takeover the management andco-ordination of a numberof on-site processes,and even ended upphysically completing workthemselves on weekends.The commitment shownby CBS at this time was wellbeyond what we couldreasonably have expectedfrom any architecturalpractice.Adventures and Lessons in Green Building11

Lessons1 The design process is the first means to avoiding environmental impact on site. Effort made by the architectsto source environmentally sound materials and suppliers and stipulate these in specifications allows lessroom for the contractor to do the wrong thing. This costs the client more. It is unlikely that the contractor willmake the effort to investigate a material supplier e.g. the quarry supplying stone to the building supplies yard.The GHP needs to weigh up the best route for achieving these levels of greenness and whether the cost is worthit. In future phases it would be ideal to have greater technical expertise within the project and time resources toresearch and monitor these issues. In the potting shed construction we couldn't stay ahead of the informationand specification process and relied on the architects.2 The Green Specification that we included in the contract documents was too complicated for anemerging contractor. Future phases of building need to simplify how these requirements are presented toan emerging contractor and/or a contractor with no environmental experience. We also need to find a way tobetter incorporate these requirements into the contract documentation at all levels, from tendering through tothe issue of payment certificates.3 A simplified green spec must be developed in the form of behaviour guidelines and site rules. Every personworking on site must sign a MoU with the project where they commit to abide by these and the principles of theGHP while involved in GHP construction.4 We need to refine the Green Specification so that we stipulate absolute conditions that must be met,for example, ‘no asbestos, no plastic’ and come up with benchmarks for other requirements. How thesewill be measured and verified is also an issue. The process of issuing payment certificates must include thismeasurement and verification. The GHP and Development Bank of Southern Africa has commissioned theCSIR to develop a simple tool for monitoring a select group of environmental indicators against benchmarksappropriate to SA to assist in this regard.5 All sub-contractors must be issued with a green spec when they quote for a job, and this must be part ofthe contract with them.6 All contractors and sub-contractors must be given free assistance to understand the requirements ofthe green spec, but compliance needs to be acknowledged in some way through payment. This could eitherbe through retention of a percentage of the contact as a penalty for non-compliance or a percentage bonus forgood work. The architects/GHP will need to develop a checklist to measure compliance.7 The contractor found it difficult to price for the green spec in the bills of quantities. A contractor'sresponse is to add on a percentage to the contract as if additional items were being required. However, manyaspects of implementing green building as outlined in the green spec did not incur extra work or materials butrather required a change in behaviour e.g. separating rubble into different piles requires the same number ofwheelbarrow trips as taking the rubble to a skip.8 Although we specified that women and local people should be employed the contractor tended to sourcepeople she knew from her own locale in the East Rand. Although management was female (the contractor andher daughter) she found it difficult to substitute women in jobs requiring heavy labour and very few womenseem to be skilled in building trades. We anticipated that many local people would ask for jobs at the gate whenthey noticed that construction had started. Based on the forms filled in at our gate, people looking for workcame into the city from townships. Several people from neighbouring flats did come to site to pick up woodscraps for their furniture business.12 The GreenHouse Project

The Dummies’ Guide to green buildingOur social objectives (local labour, more women, skills development of local people) and environmentalrequirements (conservation of resources, zero waste, no pollution, no toxics and so on) can probably be bettermet in future by using a skilled contractor and having the environmental and social requirements clearly definedin the contract.Lessons with an emerging contractor• In retrospect, the GHP realises that a green building process is cutting edge in South Africa and therefore alargely unknown quantity, even for the most experienced contractor. Although our contractor committed toa green construction process, her interest in learning new environmental building skills and compliance withrequirements waned as the building progressed.Achieving green building standards• Deciding if the architects should design the green-ness in. The design process is the first means toavoiding environmental impact on site. Effort made by the architects to source environmentally soundmaterials and suppliers, and stipulate these in specifications allows less room for the contractor to go wrong.However, architects charge a premium for their time. The GHP needs to weigh up the best route for achievinghigh levels of greenness; perhaps it needs to do research in-house. Or perhaps it is worth paying the architectsto do it.• Deciding upfront on fair charges for green practices. A contractor's response to a Green Specification isto raise prices as if additional items are required. However, many aspects of implementing green buildingas outlined in the Green Specification did not incur extra work or materials but rather required a change inbehaviour. For example, separating rubble into different piles requires the same number of wheelbarrow tripsas taking the rubble to a skip.• Bring subcontractors into the process formally by including a simplified Green Specification in theircontract and requiring that they meet these for payment.Adventures and Lessons in Green Building13

Materials used:Chapter 4:Materials chosen and avoidedProducts with lowerembodied energyNatural materialsminimising and managing the useof pesticides and other hazardouschemicals to prevent soil andwater contamination.Renewable productsThe energy that is used in extracting,manufacturing and transportingmaterials is called embodiedenergy. For example, to manufacturecement requires enormous energyto heat the cement kilns whichis supplied through the burning offossil fuels. Transporting the heavycement from kiln to site, requireseven more energy. By contrast,using locally sourced mud with asmall amount of cement to bind itfor flooring cuts out most transportcosts, as well as reducing the energyrequirement for manufacture,since mud is used as is.Traditional materialsThese include thatching grass,wood, mud, stone or reedswhich are usually sourced nearthe building site and requirelittle further processing afterharvesting. Wood may betreated.Some synthetic products are madeof non-renewable and toxic materialssuch as the petroleum usedin the manufacture of plastics andpaint. These products are not onlyresource and energy guzzling, butemit toxins during manufacture,use and after disposal. Naturalbuilding materials, such as stoneand clay brick, tend to be far lesstoxic and less processed (smallerproduction impact in energy consumption,transport and waste).Second hand materialsThese already contain embodiedresources and energy used inproduction. To re-use materialssaves on energy, resources andthe landfill space they would haveoccupied if discarded.Non-toxic materialsThese create a healthy, nontoxicenvironment. Indoors, thisincludes minimisation of the use ofsolvent-based finishes, adhesives,carpeting, and particle board,which release formaldehyde andvolatile organic compounds intothe air. These chemicals can affectthe health of building users (”sickbuilding” syndrome). In general,known toxic materials wereavoided. For example asbestoswas totally banned from the site.Outdoors this principle requiresOne should use renewableresources (wood, reeds, grass)in preference to non-renewableresources (granite, marble, plastic).This principle can be appliedto both building materials andenergy. For energy, this promotesthe use of passive thermal design,daylighting, solar heating of water,and the use of photovoltaics togenerate energy. Passive thermaldesign is defined as ‘building inharmony with the local climate,obtaining indoor thermal comfortwith minimal recourse to artificialheating or cooling’. It includesconsiderations of buildingorientation, the use of breezes fornatural cooling, solar warming ofbuildings, and even the siting ofbuildings to benefit from existingand planned vegetation.For materials, using wood asan example, this implies the use ofsustainably managed plantationsand avoiding the use of socalled‘old growth’, threatenedindigenous timber.14 The GreenHouse Project

Some of the materials chosen for the potting shed and whyBuilding structure Material ReasonFloorWalls(Internal)Walls(External)Courtyard and gardenWindows and doorsRoofCeiling insulationWater tanksWater catchment- Recycled brick pavers- Earth- Wooden tongue and grooveslats- Sawn plantation timberpartitioning that can bedissembled- Straw bale dividing wallbetween meeting room andseed beds- Clay brick- Stone- Steel windows and doorframes- Recycled tiles- Sawn timber planks- ‘Thermguard’: Off-the-shelfshredded paper insulationtreated with boron as fire andinsect retardant- Clay brick- Vitreous clay pipes- Re-use of existing gutters- Mesh to be fixed to all guttersto keep debris out of water- Second hand materials save energy, water and other resources.- Earth requires no processing, is available for free on site and is aestheticallycompatible with the pavers.- Someone had offered the GHP old parquet wooden tiles but these would haveneeded sanding and sealing before use. Also, they would need more supportthan the pine tongue and groove floor that was eventually chosen. The lattercould also be easily suspended.- Plantation timber, if grown sustainably is better than using endangeredtropical wood, or resource-hungry plastic or gypsum board (gypsum cannot bere-used). The partitioning was specially designed to be re-usable.- Straw bale building is energy conserving, low impact and inexpensive.- The original walls were clay brick. Clay brick is a familiar, trusted technology.The GHP re-used a lot of brick from inside the building and had further secondhandbricks donated. Clay brick has better thermal (insulation) properties thancement bricks.- Natural, relatively low impact materials.- Steel is sturdy, inexpensive and recyclable. A number of second-hand steelwindows were re-used.- Wood needs higher maintenance, perhaps yearly painting or varnishing,especially in the relentless highveld sun. If steel is coated with an anti-rustprimer (and new steel is generally factory-primed), it can be treated with anoccasional coat of linseed oil.- Also, second-hand steel windows of compatible size were easier to source thansecond-hand wooden windows.- New steel windows were made for the meeting room and clerestorey becausethey needed to be an unusual size.- Recycling conserves embodied energy.- Wood is renewable and is a good option if the plantations are sustainable. Inthis case we used second-hand Oregon pine flooring which is a good qualitywood.- Using a waste material to create insulation saves resources. This product is alsobiodegradable and less toxic compared to other products on the market.- Natural, non toxic material.- Natural, non toxic material.- Re-used materials.- Re-used materials.Steps - Recycled brick pavers - Re-used materials.Shade cover formeeting room- Working for Water wattle - Making use of an invasive weed, namely black wattle trees as building materialsmakes the clearing of aliens economically viable.Services Material ReasonElectricalPlumbingSecurity- High density polypropyleneconduiting- EnviroLoo composting toilet- Grey water system linked tosink and basin- Solar water heating systems- Security bars and gates usingrecycled steel- Environmental alternatives are not readily available in South Africa.- Water saving technology.- Water saving technology.- They use clean, renewable energy.- Dumped materials are re-used or bought second hand. Much embodiedenergy is saved.Adventures and Lessons in Green Building15

From theGreenSpecificationdrawn up forthe building1 The GreenHouse Projectis aiming to use materialsin the constructionprocess which do notdamage the environment,are renewable, arehealthy to manufactureand live within, and whichencourage equity in oursocial system. Materialsspecification attempts toidentify material typesand suppliers which fitthese criteria. Wheresuppliers are specifiedthe contractor shouldnot procure materialsfrom alternative supplierswithout approval fromthe Principal Agent.2 Where generic materialsare specified and nosupplier is indicatedthe Contractor shallendeavour to obtainmaterials which aremanufactured bycommunity owned orsmall business.3 Within the principlesabove, the Contractorshall also procurematerials from sources(both retail andmanufacturers) asclose as practical to theconstruction site so thatenergy embodied in thematerials through theirtransport is as low aspossible.Partitioning, shelving andflooringWood, a renewable resource, waschosen for inner partitioning,shelving and some flooring. Forexample, the inside panelling ismade of SA pine boards whichare all separately screwed in withjust two screws per plank so thatdismantled planks have very little‘damage’ and are thus highly suitedto re-use. The metal supports forthe wooden partitioning weremade from the old angle iron thatwas part of the demolished oldpre-fabricated building.An alternative to ‘expensive’wood would have been gypsumboard but this would not havebeen recyclable and is difficult tointegrate with shelving. Anothersolution would have been todesign a more open plan officewhich would also have savedmoney on panelling. Open planoffices can be functional as long asthey have some private nooks forsensitive phone calls and meetings.While wood represents a reasonableenvironmental option, woodchoice is complicated by the factthat most construction timber ischemically treated to prevent insectdamage and rot soon after harvesting.A common preservative used totreat wood is a combination of copper,chrome and arsenic salts called‘CCA treatment’ that leaves timbertinged with pale green. CCA is toxicand leaches out of timber over time.CCA treated timber shouldn’t beburnt because this releases and concentratesthe arsenic.As an alternative the GHP researchedthe use of a more environmentally-friendlyboron wood treatment.Although boron productsconforms to South African Bureau ofStandards specifications, the use ofboron is rare in South Africa.One has to make special arrangementsfor green (freshly cut)timber to be treated with the boron-basedproduct. The GHP founda boron contractor in Mpumalanga,near the plantations, and ordereda quantity of treated wood. A firstbatch arrived successfully. Unfortunatelythe plant’s kiln broke andwhen the contractor was unableto meet the deadline, the GHP decidedto use conventionally-treatedSA pine. (For further information, seethe fact sheet in the appendix).Floor, partitioning andshelving finishesThe shelving and partitioning,made of new SA pine, werepainted with EnviroTouchmilk paint (cream colour). Thefloorboards in the three offices,also SA pine, were painted withdark green EnviroTouch.The kitchen units were madefrom solid South African cedarfrom LAM woodworks. SA cedar isavailable periodically. Ironically it isthe same price as SA pine despitebeing a superior wood. Two yearsafter installation the cedar still retainsits aroma. Cedar is sometimesused to repel insects in clothescupboards. Unfortunately thecarpenter treated the cupboardswith a PVA acrylic paint, instead oflimewash, and therefore most ofthe scent has been sealed in.Window sillsRather than using cement sills, theoutside window ledges are face16The GreenHouse Project

icks on their sides and the insidesills are simply plastered brick.These methods are simple and saveresources. They are also aestheticallypleasing and inexpensive.WindowsSecond hand windows wereobtained for most of the pottingshed except for the clerestoreywindows and meeting room. Thelatter were unusual size and couldnot readily be found in the yards.Custom-made pieces of glass werecut for the glass ‘gables’ on eachend of the building.All the accessible windowframes are unpainted but havelinseed oil applied periodically toprevent rusting.Retaining-walls in thegardenIn the garden, walls have beenbuilt of stone with the top layerthickly cemented for stability.There is cement mortar betweenall the stone but on the lowerlevels it is more recessed. On theeastern side of the building theherb garden and semi-paved areais an attractive space for workersto look out on, a food garden andalso an outside meeting space.Hollow ventilation bricks havebeen used as ‘paving’. Unlikeconventional solid paving, theseallow rainwater to penetrate thesoil. Conventional paving not onlydeprives the soil of valuable water,it also results in strong stormwaterrun-off which then erodes otherareas. Pennywort, a herbal andmedicinal groundcover, has beenplanted in between the pavers.DoorsSecond hand doors weresourced from demolition yardsin Jeppestown (Tudu and MarcoBoni) – three wood and glass doorsfor the offices and two solid whitedoors for the bathrooms. Secondhand sliding doors were found forthe meeting room.Security doorsThree security gates, front doorand four bins and gates weremanufactured from scrap foundon site or at metal scrapyards. Thefront and back security doors werewelded together from the left oversheets from which machine partshad been punched. CBS architectsartfully superimposed the shapeswhich were welded together byTrent Wiggill.The burglar bars were custommade of scrap iron and some‘driftwood’ by artist, DavidRossouw. He also crafted lightfittings by cutting old pipes intohalf metre cylinders and carvinginteresting shapes into them.The security bars of thewindows overlooking the greywater treatment systems weremeant to be able to open so thatthe plants could be watered andmaintenance carried out. However,human error crept in and now thesecurity screens for the windowsthat overlook the eastern courtyardcan be opened. The lack of easyaccess to the greywater systemmay account for some of the lack ofmaintenance of these systems.CeilingThe timber rafters are from theoriginal potting shed but new SApine was bolted to the existingtrusses to extend the structurefor the roof lantern or clerestorey(the raised part that lets in morelight and where windows canbe opened in summer to let outwarm air). The ceiling was made ofrecycled Oregon pine floorboardswhich follows the roof line toexpose the roof trusses and retainthe airy volume of the originalshed. Thermguard celluloseinsulation was utilised betweenthe ceiling and the roof tiles toimprove thermal qualities of thebuilding, although in practise theexposed lantern with single panesteel windows allows too muchwarmth to escape in winter.Light fittingsBesides scrap pipe fittings craftedby David Rossouw, copperlampshades were obtainedfrom a local artist.Adventures and Lessons in Green Building17

Bathroom and kitchenfittingsMosaic workwas done inthe bathroomsfrom brokentiles and mirrorto createattractivemosaic mirrorsabove thebasins in eachbathroom. Themosaic artistswere twounskilled butinterested peoplewho learnton site by trialand error. Oneyoung man went on to receivetraining with the Creative Inner CityInitiative (CICI), in which the GHPis a partner, and is now making aliving from mosaic work. The glass,used to decorate the front steps,was collected on site.The bathroom basins werebought from Liebermann pottery‘seconds’ (in other words ‘rejects’)next to the gasworks in AucklandPark, Johannesburg.The kitchen sink is a recycledhospital basin.FlooringA dung finished earth floor wasattempted in the office spaces butwas not a success possibly becauseof insufficient research into all theregional variations on this type offlooring. Three different ‘experts’arrived with three different dung‘recipes’. The on-site soil was alsovery difficult to work – althoughsimple tests indicated it had verylow clay content the soil becamevery sticky when wet and was impossibleto smooth. The resultantfloor (too many cooks spoil thebroth) cracked and bulged andhad to be dug up. The dung floorfailure resulted in much discussionabout possible alternatives. Awaterproofing screed had alreadybeen laid allowing a very deepspace for the dung floor, so CBSrecommended a timber floor usingSA pine in the offices.High traffic passages and receptionarea were laid in ‘soilcrete’– soil with 5% cement added. Variousmud, sand and cement mixtureswere tried in trial ‘tiles’ andthe most durable mixture chosen.The red soil and 5% cementfloors were sealed with a homemadewax recipe – 12 melted candlesto half a litre paraffin. It waspolished with a mixture of meltedcandle wax, paraffin and ‘Cobra’floor polish for several weeks afterthis and now only floor polish isapplied. The red earth imparts anattractive burnished colour withoutthe addition of any oxides.Donated pavers were used toedge and create expansion joins inthe soilcrete panels. These were laidon edge to create a deeper thermalmass that can absorb heat in theday and release it in the cool ofnight. The herringbone pattern thatwas chosen is also visually pleasing.Water pipesThese were made of polyvinylchloride (PVC), a type of plastic.This happened by default. Asdeadlines loomed some details,such as avoiding plastics as faras possible, slipped through thecracks. There are alternatives tousing PVC and readers are referredto excellent work carried out byGreenpeace Australia.GuttersThese were re-used from the oldbuilding.Meeting room ‘roof’The meeting room was originallypart of an old hothouse. Lowwalls and a glass and aluminiumstructure was already there. Theshading structure above the glassand aluminium ‘roof’ was newlybuilt of wattle poles supportedon a steel frame. Wattle, or thewood of other invasive trees, isavailable from Working for Water,a Department of Water Affairs andForestry initiative which clearsinvasive alien plants from watercatchments and makes the timberavailable for other uses. Not onlyare aliens cleared to conservewater and biodiversity, indigenoustrees do not have to be felled.Meeting room wallA straw bale wall was built on topof a brick foundation to divide themeeting room from the rest ofthe glass house. ‘Green’ architect,Helene van der Merwe was theguide for the making of this wallduring a learn and build workshop.The mud was sourced on site.(See the straw bale fact sheet in theappendix).18The GreenHouse Project

Potting shed roofVarious options for roofing wereresearched- Galvanised steel, which ispure steel with zinc coatingon both sides and will last 15years without being painted.Galvanised iron roofs requireinsulated ceilings to becomemore thermally efficient.- Clay tiles, which is a naturalproduct. Either new, or at best,reclaimed tiles, could be used.- Onduline, which is a lightweightcorrugated roofing and wallcladding material, manufacturedfrom organic fibres saturated withbitumen under intense pressureand heat. The material is flexible,economical and requires onlysimple tools (saw and hammer)for fixing. It can work on roofswith a pitch as low as 8 degreesand on curved roofs becauseof its flexibility. Onduline wasfinally rejected because of someconcern that the bitumen mightleach into harvested water.The GHP was offered a new fibrecement product produced by Everite,a company that used to sellasbestos roof sheeting. The productis called Nu-Roof. At that stage,it was still being tested by Everiteon low cost housing. It was madeof predominantly natural fibresinstead of asbestos. This offer wasrejected because the small print ofthe product data sheets revealedthat the product still contained asmall percentage of asbestos, roofaccessories such as ventilators andridge caps were still made withasbestos and the product had notproved to be durable. The GHPalso did not wish to support possible‘greenwash’. At the time Everitewas taking a bad rap for continuingthe asbestos trade and for theill health of workers at their plant.We finally re-used cementtiles which came off one of theprefabricated buildings on site thatwas demolished to make way forthe entrance ramp.Window puttyResearch showed that this is abenign product made of limestone(calcium carbonate) and vegetableoil (mostly linseed). Its use wastherefore not a problem.CementCBS architect Nic Whitcuttsaid ruefully that the pottingshed refurbishment was not an‘environmental masterpiece’since a certain amount of energyguzzlingcement was used.However, the use of cement wasconsciously cut in the construction,wherever possible, becausecement is energy intensive andpolluting, both to produce andtransport. While its constituentsare mainly limestone and ash,cement needs to be heated atextremely high temperatures.MaterialEnergy toproduce inkWh/tonnePlastics 45 000Aluminium 27 000Copper 15 000Steel 13 200Cement 2 200BricksStone 200200 to 800(depending onfinish)Sand and stonesSome research was done on quarriesregarding their environmentalcare, waste disposal and upliftmentpolicies. The Quarry OwnersAssociation was contacted for theannual environmental award winnersand the contractor was askedto deal with suppliers who sourcedtheir materials from these quarries.We were not able to verify that thiswas successful.Another consideration regardingquarries is whether the quarryingthreatens any endangeredspecies or communities. For example,Willow Quarries in Pretoria ismining in one of the last remaininghabitats of Juliana’s Golden Mole.This creature is more threatenedthan the black rhinoceros. Granitequarries in Limpopo have had negativeimpacts on local villages.Damp-proofing materials(and strategies)It is likely that the old potting shedwas built without dampcourse.During the refurbishment a damproofmembrane was laid downunder the floor. The level of thegarden is lower than the pottingshed floor, which is architecturallycorrect, if one wishes to avoiddamp problems. It was, however,necessary to excavate around thebuilding to achieve this.As an old greenhouse, themeeting room has experienced itsfair share of damp problems. Thewalls were initially just plasteredoutside. After initial signs of dampin the walls the exterior waspainted with BreatheCoat. This hasAdventures and Lessons in Green Building19

not completely sealed the meetingroom since it’s been difficult toseal joints between materials thatexpand and contract at differentrates; namely the aluminiumstructure, the glass and brick.It’s also been a challenge to sealaround the skylight and betweenmeeting room roof and kitchen.Wall finishesThe interior walls were either leftas raw Rhinolite or have becomeexperimental surfaces for variousnatural paint techniques. Rhinoliteis a standard product in theindustry, a white plaster, that fillscracks and creates a smooth wallfinish. Rhinolite is not waterproof,not washable and may come offwhen you brush past. It’s thereforenot suited to hard-wearing, hightrafficareas.Rhinolite is made of phosphategypsum. It is a by-product of thefertiliser industry (not a mineralthat is mined). It is thereforeslightly more environmentallyfriendly(although chemicalfertilisers have severe negativeenvironmental impacts, causingalgal blooms in watercourses anddestroying beneficial soil bacteria,and should not be over-producedor used indiscriminately).According to CBS, to changethe colour of Rhinolite from white,you would have to coat it with afirst coat of oil-based primer andthen two coats of any paint withoutepoxy. One cannot use water directlyon Rhinolite because it dissolves.Therefore the casein paint wouldn’twork directly on this surface.The GHP chose to experimentwith natural paints. Commercialpaints are made from petrochemicalsand can be toxic – ingredientsinclude cadmium, mercury, phenols,chlorine, sulphur, formaldehydeand other volatile organiccompounds (VOC’s). These cancause symptoms for both painterand residents, varying in severityfrom headaches and nausea, tocancer. Up to 30 cans of mostly toxicwaste is produced for each canof commercial paint, and paints areby mass among the most energyconsuming building products. Variousforms of traditional paint canbe made which are less toxic anddurable. These also allow the wallsto ‘breathe’ – that is moisture andair can move freely through them.In the toilets, there is a mottledcottage cheese paint with a greenpigment. It is durable but noteveryone likes the look.Bathroom casein paintIngredients- One tub of smooth cottage cheese- Two teaspoons hydrated builder’slimeMethod- Mix cottage cheese and lime in half abucket of water- Leave in the sun for 15 minutes.- Collect the curdles. Pour off the water- Take curd and mix with half ateaspoon of linseed oil then addwhite poster paint and extra water- Apply two to three coatsA luminous blue was created onsome walls and columns by usingReckitt’s Blue, a commonly availablewashing aid, which was addedto a milk and lime paint. The piantis made by taking one part hydratedlime to 12 parts low-fat milk (byvolume/weight)Luminous blueMethod- Sieve the hydrated lime- Stir in enough low-fat milk tohydrated lime to make a cream- Add balance of low-fat milk- Now add sufficient amount ofpowder pigment to desired colourand consistency. (Pigment powdermust be limeproof)- For best results continue to stirthroughout use. (The paint can bekept for a few days until the milksours)The red paint in the kitchen wasboiled linseed oil mixed with earthand rust salvaged from old metalobjects at the GHP. (More detail onmixing and colouring natural andhomemade paints can be obtainedfrom the GHP office).EnviroTouch ‘milk’ paint wasused on the wood – chromeoxide green for the floors and acreamy colour for the shelving.EnviroTouch contains naturalelements such as beeswax,plant oils and plant extracts. Noaromatic solvents or formaldehydeare used. The ‘milk’ paint is watersolublemaking it easy to use andavoids toxic solvents for thinningand cleaning.BreatheCoat was used onthe exterior meeting room wallsand bathroom sills. This cementbasedpaint does not containpetrochemicals. When BreatheCoatis mixed with water and appliedto a surface, the polymers in itsingredients form a breathablemembrane. The apertures in themembrane are big enough to letwater vapour molecules through,but too small to let larger liquidmolecules past. So, like your skin,the walls ‘breathe’ by letting airand moisture through, but watercan't get in.Red undercoat/primer was usedfor all high level new windows.Second hand windows and securitybars and gates are only paintedwith linseed oil which needs to bere-applied occasionally.To waterproof the roofslabs above bathrooms andkitchen, bitumen and aluminiumwaterproof paint was applied. Thisis toxic but effective. In addition,the soil covering helps to protectthe bitumen insulation from sundamage.It is possible that BreatheCoatBan (a heavy duty waterproofpaint suitable for road markings)could have been used instead butit is not clear how it would haveperformed under a constant coverof damp soil.20The GreenHouse Project

Attractive red mud, found onsite, was added to the outsideplaster to avoid painting. It hasworn very well. The correct mix ofearth stabilised with cement wasobtained through trial and error.In fact the plastering was notoriginally planned. The originalbuilding was face brick whichmakes surfaces extremely lowmaintenance. It wasn’t going to beplastered except that a contractorput windows in the wrong placeand areas had to be re-bricked. Theresulting effect was messy, hencethe plaster. Because some of theholes were filled in with stock brick,the GHP will have to watch out fordamp. Paint acts as an additionalwaterproofing layer on walls. Insituations where stock brick isfinished with coloured plaster it isconventional to paint the wall witha clear sealant. As these may betoxic we have avoided this.Rubble re-useMaterials avoided:Briefly, materialsavoided orminimised werethose with thehighest cost tothe earth.‘Costs’ or environmental impactscan occur during mining, manufacture,use or disposal of materials.Known toxics, such as asbestos,were totally banned from the site.The use of toxic paints (manypaints contain solvents made ofpetroleum which release volatileorganic compounds) were mostlyavoided and only a waterproof silverpaint was used on the sod roofbecause no natural product couldbe found at that stage to performthe same waterproofing function.To avoid painting outside, the externalwalls used earth and ochremixes in the plaster as a colourant.Products that cost a greatdeal of energy were minimisedas much as possible. For examplethe use of cement, which requiresenormous fossil fuel inputs tomake, was only used as sparinglyas possible. A natural mud plasterwas used on the straw bale walland inside, mud-based floors, wereutilised. The use of second handmaterials meant that embodiedenergy was saved.Products that threaten biodiversity,such as hardwoods fromrainforests, virgin granite from koppieecosystems, stone from poorlymanaged or polluting quarries.In terms of a Green Specificationdrawn up by the GHP, hazardousmaterials were to be avoided.The Green Specificationdefined hazardous substancesas “those which are proven tobe toxic, flammable, explosive,carcinogenic, poisonous orradioactive.”The specification stated:- Contractor may not use anyhazardous substances on siteunless the materials specificationspecifically instructs or impliesthis use (as in the case of enamelpaint primer)- No pesticides (includinghousehold pesticides) orherbicides may be used- Approved hazardous materialsmay not be disposed of downdrains or onto the ground- Safe storage must be approvedDemolition rubble was put into thewillow wall diverting high volumewaste from landfill by re-using itto create a porous substrate tosupport a living fence. The willowwall was originally designed topurify and release greywater.However the water tends to beentirely absorbed by the trees.(The willow wall is further examinedin the chapter on water-savingstrategies and the fact sheet in theappendix).‘Fun & games’ with asbestosThe original roof on the potting shed was a corrugated fibre-cement roofcontaining asbestos. The GHP decided to remove the roof in the interestsof long-term safety and because parts of it were already showing signs ofdegradation. Waste-Tech quoted GHP R12 596.71 to remove the asbestos roofsheets. This included dismantling, wet spraying, double bagging and disposalby burying at a hazardous waste facility.As a gesture of ‘goodwill’, Everite, supplier of asbestos roofs, agreed toremove 150m 2 of asbestos roofing and take it to their specialised dump attheir factory. Our architects had phoned Everite previously, but were turnedaway – Everite does not have a public service to remove asbestos products.In fact, companies that manufacture toxic products should be compelled bylaw to be responsible for safe disposal of such products. To our horror, thecontractors sent by Everite proceeded to remove the sheets with grindersand hammers and no protective clothing putting everyone involved at risk.(For further information on the asbestos removal, see our newsletter article onour website and the fact sheet in the appendix).Adventures and Lessons in Green Building21

Chapter 5:Water saving technologies at the GHCThe adoption of the conservation principlefor water is of particular importanceto South Africa, where it is a limitingresource for development.Examples include – roof-top rain-water harvesting foroutdoor watering; water efficiency in buildings throughthe specification of conserving fixtures such as lowflowshowerheads, tap aerators and water conservingtoilets; and indigenous, drought resistant plants forlandscaping. Indigenous planting also reduces the needfor potentially polluting pesticides, herbicides, andfertilisers.The GHC demonstrates the following radical butpractical water saving technologies and alternativesewage systems.Many of the water-saving innovations at theGHC were as a result of Thomas Linders of LindrosConsulting. This permaculturist helped establish thegardens and select plants for the sod roof and ramp.He trained the first garden manager at the GHP, anddesigned the water cleansing systems.EnviroLoo composting toiletToilets can consume up toone third of all the waterused in a household. Eventhough it is possible tomake great water savingswith more efficient flushtoilets, the GreenHouseProject went for a toiletthat doesn’t use water atall and needs none of theusual expensive sewagetreatment infrastructure.The composting toiletis a self-contained sanitationsystem that uses verylittle energy to operate anddoes not pollute. It recycleshuman waste into usefulfertiliser for trees and ornamentalplants; a costeffective, ecological solution (our faeces are only 3%solid matter – the rest is all water!).The EnviroLoo was chosen because installation is relativelyinexpensive and it requires minimal maintenance.A system of baffles inside the toilet separates liquidsand solids. Heat and draughts created by the system dryliquids, and aerobic microbes decompose the solids. Theunique whirlybird and chimney ventilation system aidedby the increased internal temperature causes a negativepressure within the container, which ensures no backdraftinto the toilet pan, and therefore no odour.LessonsThe chimney length is designed for a normal househeight, but our toilets were dug down and inbetween quite a tall building and hothouses. Theproblem wasn’t lifting the smells away so much asthe fact that given the position they were not tallenough for the whirlybirds to catch the breezes.The tall hedge was also preventing especially thenorth toilet from getting the breeze that helps thewhirlybird to turn and therefore create the vacuumneeded to pull the smell out of the bathroom andbring air into the toilet. The other way our locationmade it difficult is that the composting toilet issupposed to be positioned facing maximum sun sothat the chimney heats up also creating a vacuum.Again as there was no other place to put thetoilets the chimney and chamber are only heated inthe afternoon a little and therefore are not gettingthe vacuum build up in the morning. Contrary towhat one might think, the bad smell that resultedwas a strong ammonia smell from urine that was notdrying out fast enough. The original toilets also hada lever that one used to ‘flush’ the toilet – actuallyit lifted a tray that emptied the faeces into anothersection of the toilet.It is best to avoid a system with any mechanicalparts as GHP discovered. A visitor ‘flushed’ thecomposting toilet rather too enthusiastically, andbroke the lever. This has now been replaced with amoving belt system connected to the lever whichis now pushed down instead of being wiggled backand forth. The chimneys have also been lengthenedand now the system works beautifully.An interesting cultural complication arose witha Muslim employee. Muslims need to wash afterusing the toilet and the fact that EnviroLoos cannottolerate the addition of water caused our poorcolleague to walk to the other side of the Centrewhere he could use a conventional flush toiletinstead.22The GreenHouse Project

Low-flow water tapsSelf-closing,push-to-operateand low-flow tapsat basins and onshowers providesignificant watersavings onceproperly adjustedfor length of timeand flow. Installing low-flow or spray taps requires theentire fitting to be replaced. These taps have aerators,small screens that screw on to taps and add air to theflowing water so that one feels as if more water iscoming out. Once fitted, spray taps can result in watersavings of 60% compared with conventional taps.LessonLow-flow taps are appropriate for situations wherepeople are tempted to keep water running such asbasins and showers. A normal tap is better for a bathotherwise slowed flow can cause the hot water tocool down.Rainwater harvestingHistorically, many communities have depended oncollecting rainwater. It is useful for gardening, washingand even drinking, if filtered and tested. Collectionmethods vary from culture to culture and some formsof architecture incorporate special designs for thispurpose. At the GreenHouse Centre, rainwater isharvested from the roof and stored in built-in tanksfrom where it is used to irrigate the garden.LessonsBuilding water tanks from scratch is labour intensive.There aren’t good, environmentally-friendlyproducts for waterproofing tanks so it has beendifficult to seal the joints. However, the ancientRomans built water tanks lined with limewash,which were waterproof, so more experimentation isrequired to find a reliable, environmentally-friendlymethod. Galvanised iron tanks last only five to 10years. Plastic tanks last longer, but are made froma highly energy-intensive, non-renewable resource(oil) and are expensive to produce and plasticleaches chemicals into the water especially if thetank heats up.The tanks have not been used much. A systemfor diverting the first five minutes of rainfall (whichcarries pollutants picked up from the roof) hasn’t yetbeen implemented.In addition, collecting water may not even be thebest option at the GHC. It may be better to lead theroof water straight into the garden via a long gutter,suggest CBS Architects.Stormwater managementThe potting shed is a low lyingbuilding, with many higher,paved surfaces around it.Stormwater runoff from theseareas therefore presents aproblem to the potting shedbuilding.In the east courtyarda soakaway for overflowrainwater has been created.(For more detail on thestormwater system, see the factsheet in the appendix. Moreinformation on stormwatermanagement can also be foundin our Water and SanitationMasterplan document, alsosponsored by OVE).To the north of the buildingare a number of plantingswhich also help absorb somestormwater. These include bedsof indigenous acacia trees, avariety of scented pelargoniumspecies as a box hedge andplectranthus groundcovers.Adventures and Lessons in Green Building23

Recycling of greywaterThe term greywater refers to all the wastewater from non-toilet plumbing fixtures and appliances (toilet water is calledblackwater). There are various ways in which greywater can be cleaned – at the GHC greywater from the kitchen andbasins is cleaned in a biolytic filter and a small constructed wetland. In future, when more buildings are constructed,greywater will also be cleaned using the willow wall. (Details of the biolytic filter, wetland and ‘willow’ wall can be found infact sheets in the appendix).Lessons from the three greywater systemsThe biolytic filter and wetland system were not well maintained with water or micro-organisms but this wasrecently rectified. As living systems they need constant care. They are meant to remain wet. Compost needs tobe renewed so that there is fresh food for the earthworms. The earthworms themselves may require periodicreplacement. The wetland system too needs care especially since there isn’t a constant flow of water into it tokeep the plants healthy. On weekends and over holidays no greywater is produced.Also the bathroom feeding the wetland system is mainly used by the men, who tend to wash their hands lessfrequently than the women, so the ‘wetland’ is not very wet.Willow wall evaluation(Excerpted from the stormwater and sanitation study sponsored by OVE).Willow wallA Wall constructed usingbuilding rubble, with treesplanted within the wall.A Held together with wiremesh.A Grey water is released froma pipe at the top of the walland allowed to filter throughthe rubble-and-tree rootstructure.A Water can be collected atthe base of the wall and thenbe pumped/gravity flow togardens for irrigation.A Gravity flows along lengthof wall to sump and thenfrom sump is pumped backto highest point of wall socircular watering process.Positive featuresAIf well designedmay be an effectiveway of dealingwith grey waterin contexts wherespace is limitedA Makes good useof rubble whichwould otherwisego to a waste siteA Wall providessecurityA Trees can assistwith cleaning of airA If well-designedis aestheticallypleasingChallengesA Careful and skilled design is required toensure that the structure functions properlyA May require use of an electric pump to getgreywater to wall and then to gardensA It must be ensured that untreated greywaterdoes not accumulate in a storage tank– greywater should also be treated witheffective micro-organisms to break downpathogensA Few working examples available todetermine effectiveness at cleaning waterA If system malfunctions, trees in wall requirespecial wateringA It needs to be ensured that the willow wall iscorrectly situated on a site so as to maximisethe use of gravityA Needs to be designed by experiencedarchitect/landscape architect/person withsufficient practical know-how of watertreatment systems24 The GreenHouse Project

Chapter 6:Energy conservation strategies at the GHCOptimal energy conservation requiresreduction of both embodied and operatingenergy.Embodied energy of building materials and productsis the total energy used in the processes of production,from extraction of raw materials to final delivery.Operating energy is the energy required to keep thebuilding at a comfortable temperature, well lit and ableto run appliances.Retrofitting an old building and using second-handmaterials are excellent ways of conserving embodiedenergy. Buildings that are correctly designed to beenergy-efficient, save their inhabitants plenty of moneyand effort in ‘operating energy – cooling, heating andlighting. At the GHP, consideration has been given to arange of energy-related concerns such as passive climatecontrol, renewable energies and the re-use of materials.Good thermal properties:Warm in winter, cool in summerThe GHC solar water heaterA solar water heater,installed on the roofof the convertedpotting shed, warmswater for the office.Solar hot waterheaters are at presentthe simplest andmost effective meansof saving energy andpromoting renewableenergy sources.Solar water heating panels use the heat of the sun towarm water. Once installed, a system requires very littlemaintenance and should last for decades. Most comewith electrical back-up to compensate for rainy days.Solar water heating is best regarded as a fuel savingmeasure, and can typically save about half of your waterheating bills. Some commercially installed systems canbe quite expensive so it is worth getting several quotes.Costs can be reduced by installing a system yourself, oreven by building your own panels. Solar water heatingpanels work best on sunny days, but still contributesignificantly to your hot water demand when it iscloudy.In Australia, before widespread installation ofsolar water heaters, it was discovered that 20% of thenational bill went on heating water to less than 100degrees celcius.Eskom’s coal fired power stations produce up to3% of worldwide CO2. South Africa enjoys one of thehighest insolation (hours of sunshine) rates in the world.The GHP installed a 100 litre Enertron solar geyserto provide hot water for washing dishes and for handwashingin two bathrooms. The solar panel has energyabsorber plates to convert solar energy into heat.These plates fit over copper tubing which carry a fluidwhich is a kind of antifreeze. The fluid heats up andflows into pipes around the geyser where it passes theheat on to the cold water. This type of panel is usefulon the highveld where temperatures can be extremeand winter frosts are experienced. If there is water inthe panel it can freeze and break. Also the panel lastslonger because the pipes are not blocked with limedeposits carried by water.LessonThe geyser has been performing well. To be mosteffective, the panels should be cleaned periodically.Systems installed in frosty areas use an ‘indirect’heating method employing anti-freeze as the liquidin the panel. This should be topped up annually.InsulationEnergy is retainedthrough the use of acellulose insulation inthe ceiling. Trading as‘Thermguard’ in SouthAfrica, this is a loose,fluffed insulation materialmade of 80% recycledpaper (mostly newsprint).The insulation was pumped into the gap between thetiles and sloping ceiling mounted above the roof rafters.Cellulose has good energy and acoustic insulationAdventures and Lessons in Green Building25

properties, as well as having low embodied energycompared to other insulation products. It requires lowlevels of a boron additive as a fire, fungus and insectretardant. Boron has a low to moderate toxicity forenvironment and health. Cellulose loose fill can be usedin the ceiling, piped into cavity walls or stud walls foracoustic and thermal purposes. Workers must wearrespirators to prevent breathing in the fine dust whenapplying the insulation. It is suitable for many domestic,commercial and industrial applications.Solar cooker and free standing ‘Sunstove’Solar cookerA built-in solar stove wasmade by CBS Architects,adapted from designsfor portable units. Solarovens are a simple, nonpolluting,inexpensiveway of cooking food withsunshine. They can beeasily and cheaply built.The one at the GHP was built using galvanised steel,insulation and a brick base with a firmly fitting woodendoor so that heat is retained. The sloping, shiny metalsides concentrate the sun’s rays at the centre of thecooker. The glass cover is stuck to the cooker walls withsilicone (which serves as a strong, waterproof glue). Thewooden door through which you move food in andout of the oven is accessed from the reception area ofthe office. (For more information see the fact sheet in theappendix).Free standing ‘Sunstove’The GHP has acommercial ‘Sunstove’that can be carriedoutside on sunny daysfor use. This lightweightstove opens in front andis effective and userfriendly.Some 10 000 SUNSTOVES® have been sold to southernAfrican users. The SUNSTOVE® is aesthetic and rugged.It cooks for six people, yielding four to five litres ofmealie-meal or rice with one to two litres of vegetablesor meat. For over seven years it has been massproduced in lots of 1 000 at a cost of $20 each in SouthAfrica (around R150).Lessons1 According to CBS, the solar cooker has proved tobe a far more useful product and a better investmentof time and materials than the water tanks.2 The cookers are not used to their full potential,partly because of the power of habit anda certain mistrust of solar cooking. Peoplehabitually cook on open fires or conventionalstoves because it is familiar and secure. A dailystaple at the GHP is traditional maize porridgeand France Maleme, administrator at the GHP,says that the built-in solar cooker does not allowfor easy, in situ stirring, so the porridge is notcorrectly cooked. Education is very important ingetting people to break old habits.Sod roofA sod (earth and livingplants) roof providesinsulation above thekitchen, bathroom andstore area at the GHP.The building is protectedfrom the wet earth aboveit by a bitumen andaluminium waterproofpaint layer and a geofabriccalled biddum.The latter is made ofpetrochemicals and doesnot degrade. Two yearsago, when the pottingshed was built,alternatives were not available. However, CBS Architectshas since learned of hemp fabrics and also ‘Bio Jute’ soilblankets (made by Maccaferri and available in SouthAfrica from African Gabions).The biddum was laid on the painted concrete andthen covered with gravel. Drainage is provided allaround via gargoyles which are made of half clay pipesand slope downwards to direct water away from thewalls and windows.Roof plants include drought resistant Seneciomacroglossis and bulbinella spp.Education is very important in getting people to break old habits.26 The GreenHouse Project

LessonThe GHP sod roof was a complex and expensiveexercise for the small amount of garden it yields.Its contribution to energy efficiency is limitedby the fact that heat is gained and lost throughthree skylights. However, the garden coveringdoes prevent the hot sun from drying out thewaterproofing which typically results in failurethrough cracks.Reflective glass on windowsCompact fluorescent light bulbsCompact fluorescent bulbs are used throughout the pottingshed. Fluorescent lights convert electricity into illuminationthree to five times as efficiently as conventionalincandescent lights. Lamp life is also about 10 x longer.Compact fluorescent lamps (CFL) can be usedin many overhead lighting situations as directreplacements for ordinary light bulbs. A CFL willconsume up to 80% less electricity in its lifetime than alight bulb and could last 12 years if burnt for only threehours per day. An ordinary light bulb converts 95% ofthe electricity into heat and only 5% into light. A CFLprovides the same amount of light from one fifth of thepower consumption. However, some people prefer thequality of tungsten light for desk and reading lamps.Taking into account both product and electricity costsfor tungsten and CFL, the ordinary light bulb guzzlesfive times more electricity and costs four times more forequivalent hours of light delivered. Although CFL areexpensive to purchase, they also have a long lifetime– not one bulb has been changed at the GHC as yet.Natural lightingThe north and eastern windows are glazed with‘Antelior green’. This glass is a 6mm laminated glass witha green film and it is quite a lot more expensive thanstandard glass. Four mm is normal window thickness,while 6mm is used for safety glass.The theory behind the use of Antelior in thewindows of the most exposed facades, the north andeast, is that it controls penetration of sun’s rays sothe building doesn’t overheat on these sides. It alsoprevents some heat loss during winter.LessonIn practise this glass is expensive and for the price,it has a limited effect on the building’s thermalproperties. The glass does, however, have anattractive finish, reduces glare from the morningsun and gives building users privacy.The original asbestos roof on the potting-shed wasremoved by Everite and reclaimed tiles from otherstructures on the site were used as the new covering.The pitched roof trusses were modified to allow aclerestory window arrangement to improve the dimlighting conditions. This enables natural light toilluminate the office on dim days without resorting toartificial lighting.Three skylights have been constructed – one overthe kitchen and one over each basin in the bathroomsto let in much-needed light. They are built as brickedchimneys with north facing sloping glass, which issecured to the ‘chimney’ with silicone. Skylights letin natural light; this means one does not use as muchelectricity for lighting.Adventures and Lessons in Green Building27

Natural heating and coolingThe orientation (east/west) and position (surroundedby high rise buildings) of the existing building greatlylimits the extent to which natural heating can beused, demonstrating the crucial importance of correctorientation and position.The roof lantern allows hot air to escape in summerand is kept closed in winter to retain heat. Large northfacingwindows capture some heat.Lessons1 The glass-roofed meeting room is too hot inthe summer and too cold in the winter. Thelarge surface area, single layer glazing resultsin heat loss. By contrast, there is a comfortabletemperature in the strongroom during winterdue to its thick walls and sod roof. At the sametime, the safe is dark and airless, while themeeting room is light and airy. Finding thebalance between light, and a comfortabletemperature, is an ongoing challenge inarchitecture.tiles were recycled from a pre-fabricated shed that wasdismantled on site. Second hand windows and doorswere used, and craftsmen were commissioned to createburglar bars, light fittings, and security doors from scrapmetal products. Recycled wooden floorboards wereused to create a ceiling. Soil from the ramp excavationwas re-used in the floors and plaster. Nothing wentto waste – old ceramic tiles and glass were used fordecoration and the aesthetically pleasing floors weremade of donated pavers.Even excavated tar and soil have been separatedinto piles for re-use later. Building rubble and excavatedearth are also being stored on site for future use; therubble has been built into the willow wall which willserve to recycle grey water and the earth will be usedto build a double-storey earth building. Some of thesalvaged steel frames have been cut and re-welded tocarry new partitions in the office space, and old steelradiator pipes were adapted to provide internal andexternal light fittings.2 The clerestorey was designed to have openingswivel windows with latch pulls. Although along hooked pole was provided for openingthe windows this system has proved to beunworkable. Because of the great length ofthe pole it can only be stored in the centre ofthe building where there is more height, it isextremely difficult to manoeuvre inside theconfined office spaces and between trusses anddifficult to control when trying to open or closewindows. As a result of the effort required thewindows are seldom opened to release hot airas they were designed to do. It is also difficult toclean the clerestorey windows.Re-using old building materialsA big part of the potting-shed renovation was toconserve and re-use existing building materials, ratherthan using newly manufactured materials. Existingstructures and materials represent considerableinvestments in energy (called embodied energy),and as a result it is important to use constructiontechniques that allow for recycling, dismantling andre-erection of structures and materials. Concrete roofDesmond Khumalo (who was the SEED advisor)participating in the strawbale wall“learn & build” workshop28 The GreenHouse Project

Energy discussion and learningThe Danes are at the forefront of energy-savingtechnologies and many Danish projects operate witha target for operating energy reduction of 20 to 30%.The International Panel on Climate Change (IPCC)recommends a 70% reduction in CO2 to stabilise globalwarming. A 50% reduction in energy use in any onebuilding would be ideal. The aim would be to create themaximum thermal comfort for the minimum energyinput. The GHP has not quantified the energy savings ithas achieved in the potting shed revamp. Such researchwould prove interesting.While the production of conventional buildingmaterials is generally energy-intensive, large energysavings coming from thermal mass in a building, whilein use, may outweigh the environmental impact ofproducing building materials.Energy wastefulness can catch one unawares. Forexample, recycling greywater sometimes necessitateshigh energy use to pump this water to where it canbe used. Therefore not all greywater recyclingmakes environmental sense. However,localised recycling using sandfilters is agood idea. The use of soakaways tosend water back into groundwateralso makes sense.As a rule of thumb, it is oftenenvironmentally more sustainableto reduce consumption rather thanto try and re-use resources. A goodexample is to try and reduce heatloss through insulation, rather thanre-using heat from ventilation air, orreducing water use rather than re-usinggreywater. Complex systems, such as reusingventilation air, tend to have hidden costs.Because energy costs are low in South Africa (pollutionis ‘externalised‘ and not factored into the cost ofthe electricity), energy saving technologies showcasedat the GHP may not initially be ‘cost-effective’ butshould become more so in future.Findings and recommendations by OVE on energyefficiency at the GHC include the fact that the thermalcapacity of the present walls was found to be sufficient.No further insulation was needed. An original plan tohave a north-facing trombe wall was done away withbecause it would heat the strongroom (unnecessary),and the northern façade was narrow compared witheastern and western facades. Also, based on sun anglecalculations, the north did not get enough winter sunsince it was blocked by high rise buildings.Materials with good thermal mass wererecommended for the floor. This advice was followedin and the pavers were used on their sides to enhancethermal mass.Generally, windows should only constitute theequivalent of 25% of floor area. In the potting shed, wehave windows and doors at 45% of floor area, with theskylights adding 15%. Double glazing, if it were not soexpensive in South Africa, could offer a way of dealingwith heat losses in winter through these many windows.Another less expensive way of controlling heat losswould be thick curtains.In winter, GHP staff would freeze if it weren’t fortheir gas heaters. The meeting room, with its glass roofis particularly cold. It was built as a hothouse and muchof it is glass.The poor original orientation, and the fact that thepotting shed is surrounded by high rise buildings thatblock both light and heat, were major challenges inthe renovation. The old potting shed had aneast-west orientation (north-south is betterfor passive solar heating). In spiteof having roof insulation, large northfacing windows, and floor withgood thermal mass, the GHC is notthermally efficient and needs heatingin winter. The building losesheat through largish windows onthe south side and through the‘lantern’ or ‘clerestorey’, the raiseddouble row of windows runningalong the roof.One could have dealt with theheating/cooling problem in the pottingshed by using additional earth or straw balewalls, to boost insulation. CBS is looking at differentheating options for future heating in the buildingincluding small infrared heaters, which are placed closeto the each working person. Small wall-mounted panelheaters could also be used. The intention would be toheat people rather than spaces.As a rule of thumb, it is oftenenvironmentally more sustainableto reduce consumption rather thanto try and re-use resources.Adventures and Lessons in Green Building29

Chapter 7:Additional challengesGetting green innovations through councilThe City of Johannesburg approved thedrawings of the potting shed renovationand surrounding earthworks on the15 th of October 2001.To expedite authorisation, building plans approval (BPA)recommended that the composting toilets are omittedand flush toilets indicated in the drawings!A lengthy process followed wherein CBS Architectstried to have the composting toilets approved. At firstBPA refused, quoting a clause from SABS 0400 thatstates that if a waterborne sewer connection is available,that one shall use it. CBS countered with another clausefrom the Building regulations and Building StandardsAct No. 103 of 1977 item 18 stating that a local authoritymay in writing permit a deviation or grant an exemptionfrom any applicable national building regulation excepta national building regulation regarding the strengthand stability of buildings.In response BPA requested comment fromEnvironmental management and made reference to an‘old Transvaal ordinance’ held by Johannesburg Water.Rand Water noted their objection to composting toiletsin the inner city but couldn’t produce the ordinance.CBS also noted the Agreement of Use between the GHPand the City, which specifically states that the Centre isdesigned to test and showcase alternative technologies.BPA only communicated with CBS verbally and CBSconfirmed conversations in writing. The result of all ofthis is that permission has neither been confirmed nordenied, and we went ahead with the installation of thecomposting toilet!Building costsTotal cost of buildingBuilding always seems to cost twice as much (and takesthree times as long) as anticipated. Materials and labourcost R539 557. Adding in snagging at R20 000 andR150 000 project management fees, the final bill for thepotting shed renovation came to around R700 000.Some critics said it was expensive especially whencompared to housing subsidies which are only R20 000.Yet the latter amount is appropriate for someonebuilding a house themselves over many years andbuying a few materials per year, not to an office for sixpeople that needed to be ready within a few months.Quantity surveying and costsContractApproximateamount (Rands)Preliminaries 51 515Alterations 23 457Earthworks 5 256Concrete, formwork and 17 482reinforcementMasonry 19 398Waterproofing 10 570Roof coverings 10 310Carpentry and joinery 8 803Ceilings, partitions and 8 192access flooringIronmongery 1 194Metalwork 30 821Plastering 10 208Tiling 3 296Plumbing and drainage 15 825Glazing 16 100Painting 15 242Site Works 87 565Total 473 295Vat @ 14% 66 261Grand total 539 557Costs per square metreThe square meterage of the potting shed iscalculated as:< Internal areas: 120m 2< External stairs and ramp: 86m 2< Eastern courtyard: 80m 2< Southern courtyard: 22m 2< Water tanks: 7m 2< Greywater systems: 6m 2< Total: 320m 2< Per square metre price R2 187.50CBS Architects commented that this was a reasonableper-square-metre price for 2002. More luxuriousdevelopments were being built for R3 500 to R5 000 persquare metre at that time.30 The GreenHouse Project

Why was the building so ‘expensive’?If one argues the case for the building being expensivethen the justification has to be in part, the way thingsare priced by our wasteful society. At present, the moderneconomy externalises the costs of pollution and as acorollary, salvaging is not ‘rewarded’.In mere rands and cents, it would have been cheaperto raze the old potting shed to the ground and buildfrom scratch using – ironically – high-energy materials,such as cement blocks.Instead, it was expensive toretrofit the old building. Costswere further raised by employingartists to take ‘rubbish’ andlovingly craft it into somethingboth useful and beautiful. Soalthough the security screenswere created from recycled steel,some of it found on site, thedoors were expensive to make.The building also used a lot of wood. Wood isrelatively expensive and this added to costs. The ceilingwas made of recycled Oregon pine floorboards. Thiswas at least correctly priced since a new SA pine ceilingwould have been more expensive. The irony is that theold Oregon pine is a higher quality wood.The brief for the potting shed was to see how far onecould push recycling and re-use, even for new materialsused. For example, the inside panelling is made of SApine boards which are all separately screwed in with justtwo screws per plank so that dismantled planks havevery little ‘damage’ and are thus highly suited to re-use.An alternative to expensive wood could have been gypsumboard. The office could have been designed to bemore open plan which would also have saved money onpanelling. Careful woodwork also added to costs.Some of the things we tried during the potting shedrefurbishment were experimental. This meant thatsome work had to be re-done. For example, the dungfloor ended up becoming a mud and paving stone floor.External plastering was an afterthought and not in theoriginal budget.The interior walls were skim-plastered with rawRhinolite to create a finished coat but then whenthe floors were pulled up and re-done the finish wasscraped and dirtied with wheelbarrows. The Rhinoliteplaster had to be re-done. This meant paying for threecoats of Rhinolite instead of two.Small buildings are also expensive because thereare no economies of scale. It is expensive to have skilledworkers on site – one foreman might cost R15 000 perproject, but if the building is huge you get many moresquare metres built for this cost.Financial management of the constructionprocess needs improvementSeveral issues arose which need to be dealt with insubsequent processesk In comparison to the amount of work put in bythe architects we felt that the quantity surveyorscharged very high fees for the service they delivered.As the client we relied on the QS to develop accuratebudgets for the project and manage payment ofthe contractor within this. We were disappointed inthat the QS charged 7% of the 15% fees allocatedalthough they were not as involved as the architectswere, and engineers and landscapers also need to bepaid. When we challenged their invoice they quotedgazetted rates. In other words professional fees areunder-quoted in budget development.k The architects alerted the QS to the need to amendthe contract with the contractor when we discoveredthat she was not able to play the management rolerequired. The QS advised the architects that thiscould be sorted out later but at the end of the projectwe discovered that the contractor had already beenpaid management fees and site establishment whichwas not necessary, and no money could be shiftedfrom the construction contract to the architects forthe extra work required in managing site. The wholesituation turned nasty when we withheld the lastpayment in an effort to get the contractor to remedypoor work on site. It turned out that she had spenther money but not paid her workers. When the lastamount was withheld she proceeded to blame theproject for the worker’s plight to the extent that sheincited workers to threaten a demonstration duringthe Centre’s WSSD opening. All of this has addedto costs and frustrations and long after completionwe are still struggling to fix defects in the buildingresulting from the contractor’s mismanagement andpoor workmanship.k In the absence of a responsible contractor and therush to make up time extra on-site supervision wascontracted and payments were being made directlyby the architects as well as ourselves. Invoices werenot always collated and sent through speedily, andthe QS did not play an adequate role in monitoringspending against items in the bills. This resultedin overspending in certain areas, which has meantdropping some components from the building.Adventures and Lessons in Green Building31

LessonsTo address the points above in future design andconstruction1 We would like the principal agent to becontracted for the whole job on a set fee rate,and for them to negotiate rates with additionalprofessionals and be responsible for signing offpayments to them against the fixed total fees.We must all be careful that additional servicessuch as typing of documents and defineddisbursements are included in this percentage.The architects will also use discretion in makinguse of other professional services only whennecessary so that professional fees are reduced.2 Collation of invoices and authorisations forspending should be controlled at one point. Ifthe GHP buys materials directly it must either beagainst very clearly defined provisional sums inthe bills of quantities or the GHP financial administratormust be empowered to manage all paymentsagainst the bills of quantity. It is by far preferablethat a main contractor is responsible forbuying materials and paying sub-contractors andthat the GHP only makes lump sum paymentsagainst properly calculated payment certificates.Challenges in communication anddecision-makingThere wasn’t always a clear framework for makingdecisions on what constituted ‘green building materials’or methods. What’s more, working with emergingcontractors, the architects had to use creative strategiesto ensure construction complied with technical, greenand aesthetic considerations e.g. working side by sidewith artisans to physically lay out components, buildinga miniature model of the solar cooker so that the insidecould be manufactured at the correct angles and so on.Problems with materials, design andworkmanshipA process of snagging (identifying and fixing defectsin workmanship) continued into 2003. The architectsbattled to get sub-contractors back to site to fix latentdefects in their work. A new contractor had to bebrought in to fix poor workmanship by AbathandiProjects and some of the sub-contractors.Perhaps the most urgent problem was the fact thatthe building was not waterproof. Rainwater outletsfrom the sod roof only flowed clear of the walls duringheavy rains; the rest of the time water dripped onto thewindow sills and then through the putty in the windowframes. The meeting room walls were also gettingdamp. The roof needed a flashing to clear water off thewall. Rainwater came in through the apex of the roofand at the junction between the roof and the parapet.The height of the meeting room walls was raised tothe underside of the glass hothouse roof. Unfortunatelythis was done in more porous stock brick with the resultthat rain was penetrating to the inside wall. In order towaterproof the plastered stock brick walls, a non-toxic,cement-based paint, BreatheCoat Ban was applied onthe outside. This, combined with non-invasive adjustingof spouts and the use of silicon to seal windows, seemsto have solved the problem to some extent. However,there is still a damp problem in the meeting room dueto an inadequate roof overhang over the walls anddifficulty sealing the junction between the glass roofand new gable wall of the kitchen.The storeroom – created by building into one of theadjacent glasshouses alongside the old shed – suffereda stormwater deluge during construction. The floodinghappened because the existing glasshouse wall wassimply raised and earth filled in behind it. Stormwaterrushing down Claim Street soaked into this soft soil andthe unprotected old stock brick wall behind it. To fixthe problem the earth had to be temporarily removedso that the porous stock brick could be waterproofedand fast draining gravel packed next to the wall. Waterbuilding up against this wall underground can nowdrain through the gravel to a drainage hole onto a hardsurface from where it flows to the stormwater system.Some of the outside paving has collapsed. We havelearned that soil needs to be properly compactedbefore paving is laid.Various materials donations have been made to theGHP. While all donations are much appreciated, theyproved a bit of a challenge during the finely timedbuilding operation. Donated goods may take extremelylong to arrive because they are nobody’s priority. Thiscan slow progress.While using second hand materials is environmentallysound because it conserves embodied energy (and savesmoney), these also pose challenges. For example, specialdoor frames had to be commissioned to accommodateunusually sized doors.A substantial argument developed with the electricalcontractor who has refused to return to fix lights andplug points that have been working intermittently. Thecontractor blames the re-used light fittings which he wasasked to refurbish. To this day the electrical work is incompleteover this impasse and there is no budget for theGHP to call in a replacement electrician to fix the problem.32The GreenHouse Project

Chapter 8:ConclusionsIs renovation viable?Social and economic principlesof sustainable constructiony Promote labour intensive construction fordisadvantaged communities as this should result ina significant portion of the financial contribution of aproject remaining and circulating in local hands.The GHP tried to employ local people and work with emergingcontractors and independent artists.Perhaps the most crucial question posedby the potting shed project – (a study inre-use and recycling) – is whether it would havebeen more environmentally-friendly to tear down thewhole building and build a correctly oriented buildingfrom scratch that operates in a more environmentallyefficient way, or to re-use as much of the old building aspossible and deal with the problems it poses?Certainly from a building ‘convenience’ point ofview, demolition and rebuilding would have beeneasier. However this would be a loss of all the resourcethat went into the original building including materialsand the energy and water embodied (through mining,growing, manufacture, and transport of the materialsused to make the original building).There isn’t a simple or commonly-used formula atpresent for weighing demolition versus refurbishmentfrom an environmental point of view. There is a need forgreater information on the cradle to grave impacts ofeach material and process to enable this kind of analysis.Working with an existing building certainly requiresmany compromises. Our potting shed presented us withpoor orientation and space constraints. Some challengesprovided for unique and pleasant solutions, but the significantissue of extreme heat and cold is yet to be solved.Is the potting shed a sustainable building?We look at various principles of sustainable construction,as outlined in the GLAD files, in a section excerptedfrom "The Attainment of Sustainable Construction: AFramework", by R. C. Hill and P. A. Bowen, accepted forpublication in the Journal "Construction Managementand Economics", prepared for an Environmental TechnologyWorkshop, the Cape Town 2004 Olympic Bid, 2 May1996, and see how the potting shed measures up.y Implement skills training to allow disadvantagedpeople to meaningfully participate in a project toensure that development of human resources is alasting legacy of construction, in addition to thephysical presence of infrastructure.All contractors and workers were given free workshops in greenbuilding and development.y Ensure financial affordability for intendedbeneficiaries - the "bottom line" principle.Our building was expensive but certain aspects are affordableto replicate; for example recycling materials, using mud in theexterior plaster mix, designing our own skylights (basically achimney topped with a piece of north-facing glass).y Choose environmentally responsible suppliers orcontractors who can demonstrate environmentalperformance.We supported an ‘alternative’ wood treatment facility and triedto find quarries which had demonstrated good environmentalpractise.. There are currently no ‘green’ building contractors,so we tried to educate our teams in green building sitemanagement. (See chapters three and four).y Seek intergenerational equity by avoiding excessiveresource consumption and not overtaxing the assimilativecapacity of the environment to absorb wastes.We were careful about materials, water and energy use. Weused as much recycled and low impact material as possible. (Seechapter four).y Pursue quality in creating the built environment.Cherished spaces are cared for and maintained whiledehumanising structures are prone to vandalism.Sustainability requires a shift away from "maximumquick profit financing" and "tight-fit designs" tobuildings that "are designed for life cycle value" andwhich embody "generous design", "modifiabilitythrough modularity” (see principle on re-use) and"cherishable delight and craftsmanship".The aesthetic appeal, use of art and vernacular craft are palpable.Adventures and Lessons in Green Building33

y Humanise larger buildings. Experts suggest that thischallenge should be tackled through a combinationof the use of "thin" buildings (which optimise insideoutsidecontact, i.e. contact with nature).The potting shed is bright, airy and people-friendly. Links withthe garden have been established on the eastern side, wherewindows overlook a pretty courtyard, and at the back, wheremeals are shared in an open eating area.y Infill and revitalise existing urban infrastructure with afocus on rebuilding mixed-use pedestrian neighbourhoods,which integrate housing, retail space, and workplaces. Experts envision "new communities as morefinely integrated, walkable neighbourhoods with astrong local identity and convivial public spaces".The GHC is sited in multi-use Joubert Park and surrounds: ataxi commuter node, a pedestrian thoroughfare, a meetingand relaxation space, creche and art gallery, surrounded byoffices, shops and residential buildings. It forms part of urbanregeneration in the area.The potting shed is bright,airy and people-friendly.Process oriented principlesof sustainable constructionThese principles seek to ensure that environmentalassessment and management is:y Interactive and consensual, in promoting interdisciplinarycollaboration and partnerships between government,industry, consultants, contractors, non-governmentorganisations and the general public.The development of the GHC has indeed been interactive andconsensual, in promoting interdisciplinary collaboration andpartnerships.y Premised on due consideration of alternatives.Many alternatives were debated before the masterplan wasagreed on.y Based on a life cycle framework for design, whichrecognises the need to consider all of the principlesoutlined above at each and every stage in planning,design, implementation and decommissioning.This has been done. (See chapters three and four).y Based on an approach which seeks synergies betweenthe environment and development and in which reducingthe use of resources also saves money.Many of the environmental features will save money, for example,solar water heater, re-use of greywater and the solar cookers.Environmental principlesof sustainable constructiony Reduce the use of the four generic resources used inconstruction, namely, energy, water, materials, andland.We tried to conserve all resources.y Optimisation of this principle for energy requiresreduction of both embodied and operating energy.We reduced embodied energy by re-using materials. We reducedoperating energy by trying to make the building as energyefficientas possible.y The adoption of the conservation principle for wateris of particular importance to South Africa, whereit is a limiting resource for development. Examplesinclude: roof-top rain-water harvesting for outdoorwatering; water efficiency in buildings through thespecification of conserving fixtures such as low-flowshowerheads, tap aerators and water conservingtoilets; and indigenous, drought resistant plantsfor landscaping. Such planting also optimises forprinciple E5 through reducing the need for potentiallypolluting pesticides, herbicides, and fertilisers.We harvest rainwater, have low aerator taps, water conservingtoilets and drought resistant plants. Our garden uses no fertiliersor pesticides.y Maximise resource reuse and/or recycling. Examplesof reuse include the renovation of existing buildingsand refurbishment for a new purpose.We renovated the potting shed and turned it into an office. Were-used as many components as we could on site. We institutedon-site sorting of usable waste.y Use renewable resources in preference to nonrenewableresources.We used wood instead of plastic. We installed a solar waterheater which uses renewable energy.y Minimise air, land and water pollution.On site, we managed noise, odour, dust and solid waste. Wereduced our use of chemicals to the minimum.y Conserving or restoring life support systems and thebiodiversity of plants.In our natural water treatment systems, our compostingtoilets, our stormwater infiltration system and our organicgardens we have restored something of the naturalecosystems that used to occur in Joubert Park We notice thatbirds and butterflies, local people and children find refuge inthis beautiful, productive green corner of Joubert Park Thathas to mean we’re heading in the right direction.34The GreenHouse Project

Chapter 9:AppendixThis chapter offersfact sheets on manyof the technical detailsof our potting shedconversion.These fact sheets areintended to empower allwho share our vision.Please feel free to use,copy and disseminatethese fact sheets, as longas you credit the GHPas the originator ofthese resources.Further fact sheets areavailable in our GreenLiving and Development(GLAD) Fileson our website atwww.greenhouse.org.zaFact sheets:x Summary of the Green Specification used during thepotting shed conversion...pg 36x Straw bale construction...pg 38x Solar cooker...pg 40x Sod roof...pg 41x Mini wetland for cleaning greywater...pg 42x Biolytic system for cleaning greywater...pg 44x Living willow wall...pg 46x Storm water drainage system...pg 48x Asbestos...pg 50x Timber preservation...pg 52Adventures and Lessons in Green Building35

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Summary of the Green Specification(used during the potting shed conversion)GreenA holistic approach to ourenvironment which placesecological sustainabilitywithin the framework ofsocial justice, equity and abetter quality of life for all.PURPOSE OFSPECIFICATIONTo find a way to guide the contractorsbehaviour on site and throughthe construction process.Influence decisions aboutpurchasing of bulk materials basedon life cycle of material prior toconstruction.SUSTAINABLECONSTRUCTIONSPECIFICATIONConstruction phase 1:Conversion of potting shedPREAMBLE= Purpose of GH Centre= Importance of this constructionprocess as a learning example– spotlight on the GHPOBJECTIVES= Conversion of the potting shedto pilot Green constructionprocesses at CentreAim of specification – to ensurethat construction activities areconducted in an environmentallyand socially responsible manner by= Stipulating measures againstwhich the environmentalperformance of the Contractorwill be measured= Providing for capacity buildingprocessesGENERALEnvironmental awareness= Contractor and all staff toattend half day workshopwithin first two weeks on site= Contractor to ensure that allunderstand and comply= Contractor can requestassistance through principalagent (in this instance thearchitect)= Contractor recognises value ofmutual learning processCompliance with specification= Contractor must comply= Failure to comply? – correctionor remediation of damage tothe cost of the contractorMonitoring of environmentalperformance= Principal agent (PA) responsiblefor monitoring and reporting onenvironmental performance ofcontractor= All instructions to contractorthrough the architect= Provision for extra outside partyto carry out this roleDocumentation of constructionprocess= Need to document process forlearning= Contractor to make siteavailable for this= Contractor’s role – Terms ofreference to be given:• Diary to record what happens– events, questions, learnings• Document labour stats (gender,home address)• Document where materials comefromSITE ESTABLISHMENTSite layout plans= Contractor is responsible forproviding layout plans showing:• storage of materials• water and waste managementstrategy• areas to be cordoned off forprotection= Signed off by principle agent (PA)Demarcated areas= Vehicle access= Safety of excavations= Clearing of site restricted to areaagreed= Storage of rubble and wasteonly where agreedConstruction managementprogramme= Contractor to supply proposedlabour schedule in conjunctionwith work programme – agreeon:• local labour component for theconstruction team• proportions of women to beincluded in the team• Scheduling of ‘learn and build’opportunities= Contractor and PA to proposemethod for recruiting locallabour before constructionstartsFAUNA AND FLORA= Protect areas of naturalimportance= Provide access for relocation ofplants and animals before siteclearing= Contractor may not removeplants or animals withoutapprovalSOILTopsoil= Topsoil to first be strippedfrom any area where it may becompacted or polluted= Contractor to:• Keep topsoil and subsoil separatefor later reinstatement• Prevent erosion of stockpile andfree of weeds= Weed control chemicalsforbiddenSoil erosion= Contractor to implementmeasures to prevent general soilerosion on siteThe GreenHouse Centre is strivingto be a zero waste facility36The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaSummary Green Spec cont’dWATERWater bodies= No waste materials may beplaced in any water bodies= Only piped water or rainwaterharvested on site may be usedfor construction work= Contractor to provide litterand silt traps to preventcontamination of water bodiesStorm water control= Natural runoff should bediverted around site workings toprevent pollution= Storm water control to beimplemented= Storm water accumulated inworkings needs to be tested forcontamination before releaseWater conservation andpollution control= Contractor to prevent waterwastage= Contractor to implement watersaving strategies e.g. re-usingwater for cleaning tools in nextdays mix= Mortar to be mixed on nonporoussurface or mixing trays= Contractor to supply owncontainers to harvest rain wateruntil water tanks erectedHAZARDOUS SUBSTANCESHazardous substances are thosewhich are proven to be toxic,flammable, explosive, carcinogenic,poisonous or radioactive.= Contractor may not use any hazardoussubstances on site unlessthe materials specification specificallyinstructs or implies thisuse (as in the case of enamelpaint primer)= No pesticides (including householdpesticides) or herbicidesmay be used= Approved hazardous materialsmay not be disposed of downdrains or onto the ground= Safe storage must be approvedHazardous waste= Awareness of, careful handlingand storage= Disposal by approved hazardouswaste contractor= Avoid the use of substanceswhich generate hazardouswastesWASTE MANAGEMENT= GreenHouse Centre is striving tobe a zero waste facility= A waste management strategyfor dealing with all wastesgenerated in the constructionprocess, and generally by staffmust be signed off= Site to be kept free of litterPrevent or reduce – e.g. by usingdrop boards for plasterRe-use= Careful dismantling of existingbuildings= Storage of useful waste created= Client will sell or give awaywasteRecycle= Separation of all waste= Recycling of paper, tins, plasticand glass is a minimumrequirement= Contractor to establish acomposting areaDisposal= Licensed landfills, no illegaldumping, no burning of waste= Rubble not to be used forlandscaping without approval= Contractor and PA to createsystem for logging of wastedisposed ofWaste water Effluent= Effluent may not be disposed ofinto storm water= Prevent contamination of stormwater and soilSewage= Prevent sewage contaminationof surface and groundwaterENERGY EFFICIENCY= Contractor to conserve energyat all times• E.g. maintaining equipment• Using cfl bulbs• Switching off lights etcAIR QUALITY= Control of dust on site – may notuse oils= Control of air pollutionemissions of vehicles andmachinery= Ensure employees wearprotective gearNOISE= Control of noise= Ensure employees wearprotective gear= Control and monitoring ofevening, weekend and holidaywork – liaison with localresidents for over-time workCOMMUNITY IMPACT= Lighting must not be intrusive= Contractor to ensure publicsafety – monitor excavations,movement of vehicles etc= Client responsible for communityliaison but contractor tosupply information and attendmeetings if needed= Contractor responsible for keepinga log book of written and verbalcomplaints for referral to PA= Contractor responsible forremedial actionsLocal labour= Proportion of local labour andpercentages of women to beagreed= Contractor to keep a log ofpeople requesting employmentat the sitePROCUREMENT OF MATERIALSNote intention to use nondamaging,healthy and fair tradematerials= Contractor may not findalternative suppliers for thosespecified without approval= Contractor to buy from SMMEand community owned businesswhere possible= Within above frameworkmaterials to be supplied fromclosest supplier to reducetransport energySITE REHABILITATION= Contractor shall rehabilitate thesite as required by PA xAdventures and Lessons in Green Building37

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Straw bale constructionBuilding with straw bale is anextremely environmentally-friendlymethod because the main material,straw, is a renewable resource, in factan annual crop which is easy to growand plentiful.One can bale wheat straw, hay oreven veld grass. The mortar andplaster is earth, another relativelyabundant, low-tech and often freeresource. Straw bale is durable,fire resistant when snugly packedand plastered, and has thermalqualities that are superior toconventional bricks.Straw bale can be used to buildentire houses or simply for specialfeature walls, seats or other smallerstructures. At the GHC, we usedthe technique to build one wallin the meeting room. This room,being a revamped glasshouse,has poor thermal qualities. It washoped that straw bale wouldimprove this somewhat. The wallalso has sculptural and decorativequalities. Its overall purpose was toprovide a teaching function; bothin its creation and as an exhibit.Two ‘truth’ windows, like eyes,reveal the straw inside the wall toall who care to learn. One largercentral window looks into theadjoining glasshouse.The wall was constructedduring the course of a ‘learn andbuild’ workshop at the GHC.The labour was not only free, theconstruction served as learningexperience for GHP staff and otherparticipants.The following were prepared inadvance= Foundation bricks and concrete= Six baling pins set into theconcrete and protruding about450mm= Eighteen straw bales plus extrafor the fill and cob (30 hay orveld grass bales obtained)= Polypropylene string to retiebales into halves= Additional bale pins – 12 pinsat 900mm made of recycledconduit pipes. At higher levelsit would be more practical touse shorter pins or bloudraadstaples= Bale staples – consisting ofstrong wire at 3 or 4mm bentinto U-shaped staples to pinacross bales, 30 were required= Galvanised hoop iron to fix toside walls – 8 pieces of 600mmlength with steel nails to fasteninto the wall at every course= Cob mixture for plastering (thiswas made on the day)= Bale pins (steel rods)= Four dowels at 12mm diameterand 300mm long= Tools included a wheelbarrow,angle grinder, hacksaw, woodsaw, drill, extension cords,pliers, hammer, nails or screws(for wooden lintel), mallet (forknocking in pins or tweakingbales), plumb line large sheetof black plastic for mixing mudplaster and cob on, buckets,spades, bale needle, orangebags, ladder (extra bales areuseful for scaffolding), broom tosweep up loose strawFor the ‘truth’ windows= A wooden window frame= A wooden lintel= Glass to fit= Sill= Small amount of wire meshHelene van der Merwe, an architectwith a special interest in sustainablebuilding presented the workshopon straw bale walling. It ranover two days to accommodateall the participants in the small,enclosed space earmarked for thewall. Participants could not all workat once and had to wait their turn.Before the workshop, thearchitects made sure there wasa foundation and low brickworkplinth on which to build thewall. Spikes were built into thefoundation to act as the firstsupports for the bales – we usedleftover electrical conduit pipefor this. No plastic damp coursewas used on top of the brickwork,although we placed several flatquartz stones along the wall as anold fashioned moisture barrier.The space and materials werealso prepared beforehand. A tarpaulinwas laid down to protectthe floor. The straw, which wasactually mown, and baled grassobtained from a farmer livingnear Helene, was placed nearby.Outside sifted earth, sand and claywere ready for making the cob. Formaking the cob mixture, the grassstraw was cut into shorter lengthswith garden clippers. Mortar iscommonly made of clay and water,worked to consistency like thickporridge. A handy method of mixingis using a shallow trough andchurning the mud with Wellingtonboots – we just trod ours on a tarpaulinlifting the edges to keep themixture in the middle.38The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaStraw bale construction cont’dSThe bales were laid like bricks,course by course, overlapping theway bricks do for strength. Steelbale pins, measuring half a metre,can be inserted vertically, everytwo or three courses, to tie coursestogether, for extra strength. Weused our conduit again, that wecut into shorter lengths with ahacksaw.Where a half or quarter baleswere required, bales were dividedusing a special technique inwhich the sections are ‘sewn’together before the bale is split.Dividing bales is facilitated witha homemade tool called a ‘baleneedle’ made of wire. You use thisto simultaneously divide and restitchthe bales.Besides the vertical pins, heavygauge wire was also used to helppin the bales together sideways.We shaped the wire into whatlooked like huge staples that werehammered into adjoining bales.There was no frame at the topof the wall, nor was it tied intothe brickwalls to the side, andconsequently the top becamewobbly. Perhaps the wall shouldhave been designed to be under aroof truss and one could have tiedbale supports to the trusses above,comments Helene.However, by placing people oneither side of the wall, participantswere able to push the wall straight.Loose straw, stuffed into orangebags, was used to fill up the finalsections at the very top under theceiling. A wooden window framewas also set into the wall on dayone and held in place with wire.Day one ended with roughplastering with a cob mixture.Amazingly this stiffened thewobbly wall to an imoveablemass by the time it dried thenext morning., converting thepreviously skeptical foreman onthe spot. There is some scienceto cob – it is a mixture of sand,clay, water and straw. The theoryis that you take whatever soilis available on site because it isenvironmentally costly to shipsoil in from far away. You analyseyour soil and augment it until youhave the correct consistency. Youcan test the soil by rolling andsqueezing it, to see if it is high insand or clay. Clay sticks togetherwhile sand breaks apart. If your soilhas a high clay content you haveto add more sand and vice versato get the perfect mixture. Theplaster is worked into a smooth,glutinous mixture the consistencyof cement plaster by churning itwith gumboots. It feels right whenit is not too runny or sandy thatit won’t stick together, but not sostiff that one can’t work it into thewall.Ideally a straw bale wall shouldreceive three coats of plaster– the first is rough and straw-richwhich is punched and proddedinto the bales to create a key forsubsequent layers. The secondis smoother with shorter piecesof straw and worked on andsmoothed over.The final coat is the smoothestof all. The GreenHouse staff cuttheir straw into small pieces withgarden scissors. Some buildersuse bran for this layer and othersput their straw through a leafmulcher. GHP staff worked on theirown for the final layer of plasterand created sculptural shapes,decoration and whimsical touches.A unique touch in the pottingshed was the use of two ‘eyes’or ‘truth windows’ in the wall toreveal the straw underneath. Thesewere made by two panes of glass,tied in place with wire and thenplastered in place. xFriends of the GHP gathered for a Learn & Build workshop on straw bale construction and built the meeting room wall.Adventures and Lessons in Green Building39

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Solar cookerTwo cooking surfaces have been created on the northern façade on either side of the front door. Onthe left is a built-in solar cooker and on the right, a space on which the portable cooker can be placed.The built-in cooker was designed by CBS. A brick housing was created to hold aspecially made galvanised steel ‘oven’. A sheet of glass was stuck on top with silicone.The shiny sides of the oven are specially angled to concentrate the sun’s rays on the pot.Recycling spaces havebeen created underneath thesolar cookers. In the front ofthe building in the receptionarea there are two windowseats built of bricks andcovered with a wooden top.The top can be lifted to revealtwo compartments on eachside. The four compartmentsare awaiting bins for paper,glass, tins and plastic whichcan be disposed of from theinside of the building. Onthe outside of the building,these ‘compartments’ eachend in a small door (alsowelded from scrap to matchthe front door security gate)so that recyclables can thenbe removed for recycling.There are two corresponding‘benches’ on the outside ofthe building whichare ‘tables’ tosupport thetwo solarcookers.One isbuilt inand theother isa freestanding‘Sunstove’.xConstruction detail byCBS Architects40The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Sod roofDrought tolerant flowering plantse.g. Gazanias, Bulbine FrutescensSoil mixed with a polymer(Terra Wet) to hold waterFacebrick parapetSize: 6.7mm gravel in alayer 50mm deepGravelBitumen waterproofingTwo layers ‘geotextile’ (synthetic fabricthat doesn’t rot)Screed to fallsClayrainwaterspoutRoof structureAdventures and Lessons in Green Building41

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Mini wetland for cleaning greywaterAquatic plants planted directly into gravelGreywaterUpbend keepsgreywater inpipe so it cantrickle out evenlythrough drilledholessloping baseCleaned water seeps intogarden soil through holesdrilled in 50mm water pipe6.7mm gravellaid 500mm deepBend in outlet pipe allowswater to remain in thebottom section of wetland42 The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaMini wetland cont’dA small artificial wetland was designed by Thomas Lindersfor the potting shed of the GreenHouse Centre to clean thegreywater from one bathroom.The term ‘greywater’ refers to wastewater fromplumbing fixtures and appliances like a basin, but doesnot include water from the toilet. Wastewater from thetoilet is called ‘blackwater’.How the wetland worksConstructed wetlands mimic the processes that occurin natural wetlands. Decomposer organisms such asbacteria, fungi, and actinomycetes live on the surfaceof the roots of aquatic plants and soil particles. Theseremove and break down dissolved and particulateorganic material turning it into carbon dioxide andwater. They are also able to break down complicatedchemical compounds into the simple building blocksof nature, so that they can be utilised appropriately.Certain aquatic plants even exude bactericidalcompounds from their roots that eliminate harmfulbacteria.All aquatic plants pump atmospheric oxygen intotheir submerged stems, roots, and tubers. Oxygen isthen utilised by the aerobic microbial decomposersattached to the plants below the level of the water.Plants also play an active role in taking up nitrogen,phosphorus, and other compounds from thewastewater. This active incorporation of nitrogenand phosphorus can be one mechanism for nutrientremoval in a wetland. Some of the nitrogen andphosphorus is released back into the water when theplants die and decompose. However, much of thenitrogen that comes into the wetland in the form ofnitrates is converted to nitrogen gas through processesin the wetland.Size of wetlandThe horizontal area of this type of wetland (verticalflow wetland) is calculated on the rule of thumb thatapproximately one square metre is needed to treat150 litres of household water. (Compared to a horizontalflow wetland which needs approximately eight -10m 2 /person/day).To work out how many litres of wastewater yourcreate add up how many basins, sinks or baths of wateryou might use on a busy day. You can work out thevolume of each by taking the length x breadth x depthof the fitting to get a measurement in centimetrescubed. Convert this to litres by dividing by 1000.(One litre = 1000cm 3 ). To work out how many litres youuse in the shower or with a running tap, measure howmany minutes it takes to fill up a container. You canwork out the volume of the container and then estimatehow long you spend in the shower on average. Forexample if your container holds two litres and takes twominutes to fill then if you normally shower for10 minutes you use – 10 minutes divided bytwo minutes = 5 x 2 litres = 10 litres.MaintenancePlants used in theconstructed wetland at theGreenHouse Centre include= Cyperus textillis(Small papyrus – a generalcleanser),= Acorus Calamus(Sweetflag – bactericidal plant),= Schoenoplectus lacustris(a bulrush – a generalcleansing plant)The wetland is maintained by cutting off the deadparts of the plants after winter. The wetland can alsobe dosed with EM occasionally if there is a build up ofsoapsuds. The bent up pipe-end can be used to cleanthe wastewater pipe if it blocks. xAdventures and Lessons in Green Building43

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Biolytic system for cleaning greywaterShade net holding compost withearthworms between two layersof bark. Greywater seeps out ofholes in pipeRemovable cover over filterGreywater200mm layerof gravelUndergroundcleaned waterseeps out ofholes drilled ina 50mm pipewhere plant rootscan use it44The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaBiolytic system cont’dWhat is inside the GreenHousebiolytic filter?The biolytic filter was made by laying down a piece ofshade net, which would later be wrapped up the sidesand over the top of the filter medium.The following were layered within the shade net:A small Biolytic system has been built at the potting shed of theGreenHouse Centre to clean the greywater from one bathroombasin and the kitchen sink.The term ‘greywater’ refers to wastewater fromplumbing fixtures and appliances but does not includewater from the toilet. Wastewater from the toilet iscalled ‘blackwater’.What is biolytics?Biolytics is a system for treating wastewater thatwas invented in 1990 by an Australian named DeanCameron. It was first used in South Africa in 1999 bythe Spier Wine Estate, and it worked successfully.The Biolytic filtration system is an aerobic, selfsustainingprocess that uses the organic nutrientsin the wastewater to feed a balanced mix oflarger decomposer organisms, earthworms andmicroorganisms forming a biologically complex androbust ecosystem.Size of filter= 150mm of rough bark,= 200mm of half decomposed compost containingearthworms and other macro-organisms,= 50mm barkThe bark was soaked in a solution of EM (effectivemicroorganisms) for a couple of days before it was used.A 50mm pipe with holes drilled into it sprinkles thegreywater through the filter. Block off the end of thepipe so that the water is spread evenly along the pipeand wont gush out of the end.MaintenanceThe system should be maintained by refilling the halfdecomposedcompost (including earthworms) at leastonce a year and dosing the whole system with EM (orcompost starter) twice a year to maintain the bacteria.It is best to feed the cleaned water that comes out tothe roots of plants such as shrubs, trees and fruit trees.At the GreenHouse, water hungry granadillas growvigorously at the outlet pipe. xApproximately 1m 3 of biolytic filter is needed to clean500 litres of greywater per day.To work out how many litres of wastewater yourcreate add up how many basins, sinks or baths of wateryou might use on a busy day. You can work out thevolume of each by taking the length x breadth x depthof the fitting to get a measurement in centimetrescubed. Convert this to litres by dividing by 1000. (Onelitre = 1000 cm 3 ). To work out how many litres you usein the shower or with a running tap, measure how manyminutes it takes to fill up a container. You can work outthe volume of the container and then estimate how longyou spend in the shower on average. For example if yourcontainer holds two litres and takes two minutes to fillthen if you normally shower for 10 minutes you use: 10minutes divided by two minutes = 5 x 2 litres = 10 litres.Adventures and Lessons in Green Building45

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Living willow wallGreywater piped to highest pointTrees planted onoutside of fence300mm apart2.5 metre highwattle & pig wire fence(half a metre shouldbe submergedin rubble)75mm waste water pipe –lies loose on rubble & ismoved up as wall grows300mmRubble packed into800mm x 800mmtrench and betweenfencing110mm ‘geopipe’ collects cleaned waterfor storage in a 2 x 2 x 2 metre underground brick tank46The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaLiving willow wall cont’dIf you visit the GreenHouse Centre you will see a strange construction built around thenortheast corner. This is the beginnings of a living wall, designed by Thomas Linders, that hasmany uses.The wall:= Creates a protective boundary to the GreenHouse Centre= Uses building rubble instead of dumping it= Cleans greywater= Provides a habitat and food for birds and insects= Controls noise from the streetHow it worksThe rubble is packed into a trench and between two rows of fencing that make the centre of the wall. Thetrench was lined with plastic to stop the water from seeping away. A row of trees is planted on the outsideof each fence. Wastewater sprays out through sprinkler nozzles fitted into holes drilled in a pipe that runsalong the top of the rubble wall. The roots of the trees grow into the rubble seeking the water and nutrientsand as the water trickles down through them it is cleaned. Clean water is collected by a perforated pipe atthe bottom of the trench and gravity flows down to a collection tank. The clean water in this tank can bepumped out for use in the garden.The building that will supply wastewater to the trees has not been built yet but we needed to start usingthe rubble and growing our protective wall. For this reason water collected in the tank is currently pumpedback onto the wall and we have to water the trees in dry months. When completed the wall will standtwo metres high.Which trees?The trees that were chosen are all water loving plants. It is the microorganisms that live around the rootsof the trees that break up the chemical compounds in the greywater into nutrients that the trees can use.Although we call this a Willow wall a number of different trees have been planted. All of them including theWillows are indigenous to South Africa. Each type of tree adds to the living fence in the following way:Common name Latin name The reason it was usedCape Willow Salix mucronata Deciduous, fast growing, creates huge root mass to hold rubble togetherRiver Bush Willow Combretum erythrophyllum Deciduous, fast growing, nesting for birds, bee fodderOtterbessie Gomphostigma virgatum Evergreen, flowers for insectsTree Fuchsia Halleria lucida Evergreen, flowers for birds and butterfliesDogwood Rhamnus prinoides EvergreenOldwood, Ouhout Leucosidea sericea Evergreen, nesting place for birdsKatdoring Acacia caffra Deciduous, attracts bees and birdsMaintenance of the wallThere are two important things to do to maintain the wall, especially in its first few years – ensure a fairlyconstant source of greywater and weave!The bark of trees in the willow family is very special because it contains a natural growth hormone.This helps in developing the living fence. As the trees grow the branches of the willows should be woventogether. Over time these woven branches may actually grow together and will send new roots out intothe rubble in search of the moisture and nutrients trickling through it. In this way the trees will enmesh therubble, holding it in place so that by the time the wire fencing has rusted it won’t be needed anymore. xAdventures and Lessons in Green Building47

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Storm water drainage systemEntrance ramp400 x 400 x 500mm sumpUnderground pipeLayer of geotextile(biddum)200mm topsoilTerracedgarden400mm layer of19mm stonerubble230mm retaining wallswith drainage holes48The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaStorm water drainage system cont’dThe next thing to work out is how quickly this waterwill drain away into the soil surrounding the infiltrationpit. Research has shown that over time accumulatedorganic matter can cause the pit bottom to block.Therefore only count the square metre area of the sidesof the pit when you do this calculation, and not the areaof the bottom.The rule of thumb is that the water will drain atbetween:= 10 litres/m 2 of area of the side of the pit/day in siltyclay soils= 25 litres/m 2 /day for sandy soilsThe potting shed was originally built with three sides of thebuilding submerged in soil.During the renovations the architects excavateddeep steps into this bank of soil to create a gardenand provide access to the building. This excavationposed a challenge during rainy periods, as it couldquickly fill with storm water and flood the building.Conventionally one might need a sump, many metresof piping and a pump to take the water out and intomunicipal storm water drains. Rather than taking thisroute, however, our water consultant, Thomas Linders,and CBS Architects designed a system to quickly drainstorm water into the subsoil where it will replenishgroundwater. See the diagram of this system for details.The main component is a rainwaterinfiltration pitThe size of the pit can be worked out using thefollowing guidelines:First of all try and work out what volume of rainwateryou might have to deal with. Contact the weatherbureau to find out what the average maximum rainfallis in a day for your area. Then measure the area of thesurfaces that feed run-off water into the area that youare trying to drain. For example does the rain flow from aroof, stairs, or paving. Work out how many square metresthis is and then times this by the number of metres(millimetres divided by 1000) of rain expected duringthe highest daily rainfall. You will now have a measure ofthe volume of water, in metres cubed, you can expect ina day. From here you could work out the size of pit youmight need to simply hold the water that fell.(one litre = 1000cm 3 , to work out litres multiply metrescubed by 1000)You may need to increase the surface area of the sidesof your pit if you need the water to drain faster.In addition to using this rule of thumb it isrecommended that you do a percolation test to seeif water will drain away quickly enough to use aninfiltration pit in the soil you have.Percolation test= Dig a 300mm square hole 250mm deeper than thedepth of the planned depth of your drainage pit.= Fill the hole with water and leave it to soak awayover night.= The next day (when there is no water in the hole)refill the bottom 250mm of the hole with water, butnow measure the time it takes for the water to drainaway.= Divide this time in seconds by 250 to get thepercolation value Vp.= If the area you will be using for infiltration is largedig several holes in different places and test eachone. (Don’t do the test during abnormal weatherconditions such as heavy rain, severe frost ordrought).If your soil has a percolation value of more than100 seconds/mm it is probably not a good idea to use arainwater pit, although if you have light rain and designcarefully values up to 140 are acceptable. xAdventures and Lessons in Green Building49

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: AsbestosWHAT IS ASBESTOS?Asbestos is an incombustible,chemical-resistant fibrous mineralused for fire proofing and electricalinsulation or as reinforcement inbuilding materials. It is mined fromasbestos containing rock, which iscrushed and milled to produce rawasbestos. There are several types ofasbestos, and all cause cancer. Blueasbestos, of which about 70% wasmined in South Africa, is knownto be particularly carcinogenic topeople who breathe it.DANGERS TO HEALTHAsbestos breaks down into fibresthat are so small they can bebreathed into the deepest partsof the lungs, where they lodge inthe sensitive tissue. These fibresmay cause asbestosis, lung canceror mesothelioma, a cancer in thelining of the lungs. No one candispute the connection betweenasbestos and health problems.However, it sometimes takes 30years or more for an illness toshow, which makes it hard to convincepeople of how serious theproblem can be. Initial exposurecannot be detected because thereare no early symptoms, and evenmedical x-rays cannot determineexposure. These time-gaps makeit hard for people to prove claimsagainst mining companies, manufacturesand installers.LOCAL CONTEXTSouth Africa used to be the world’sthird largest asbestos producer,making asbestos mining and materialsproduction a particularly relevantlocal problem. In South Africa,asbestos was mainly mined in theNorthern Cape, Mpumalanga andLimpopo Province. Tens of thousandsof South Africans went towork day after day in the asbestosmines without any form of protection.Many of the harmful fibreswere breathed in, remaining intheir lungs. Family members werealso affected as miners carriedthe fibres home on their clothing.Open waste dumps from the mineswere scattered amidst communities.Yet the miners were unawareof the risks. They didn’t even usea simple mask, which could haveprevented 90% of the deaths.Many of the miners andmembers of their communitieshave become seriously ill or havedied. Groups of affected minersand their families have sued forcompensation for their suffering.Everite, a company manufacturingasbestos products, is also beingsued by cancer victims.Although asbestos miningoperations have stopped in SouthAfrica, asbestos is still importedfrom our neighbour, Zimbabwe.Nine companies in South Africause asbestos in their productionprocesses, mainly in the motor industry.Everite manufacture buildingmaterials containing asbestos,although they are now developingsafe alternatives. For example, cellulosefibres can replace asbestosin asbestos cement. Everite havedeveloped a comparable newproduct called “NuTec” to replaceasbestos cement tiles.AVOIDING EXPOSURE – WHERETO LOOK OUT FOR ASBESTOSDespite the known impacts onhealth asbestos continues to beused in many products. All aspectsof asbestos related mining, transportation,processing, productmanufacture and ongoing use posea risk to the people involved inthese processes and in the vicinity.Miners are at greatest risk, sufferingthe highest proportion ofdeaths from asbestos related illnesses.Where mining companieshave not rehabilitated asbestosmines, nearby residents are also exposed.Often there are no warningsigns near asbestos dumps, and theroads to some of the abandonedmines remain strewn with asbestos.A quarter of people affected byasbestos worked in the buildingtrade, having breathed in asbestosdust during their day-to-day workor because work with asbestos wascarried out near them. In SouthAfrica, asbestos is mainly used inbuilding materials and pipes, oftenmixed in various percentages withcement. Building materials includeroof-sheets, walls, ceilings, gutters,chimneys, sewerage pipes and waterpipes. In the past asbestos wasused in many other building materialse.g. insulation boards and vinylasbestosfloor tiles. Although this isno longer allowed, both these olderand more recent asbestos containingbuilding products are still inplace in buildings. For examplemany houses in Soweto have asbestos-cementroof sheeting becauseit was a relatively cheap material.Homeowners may be exposed tolow levels and risk is increased ifthe materials begin to break apartthrough weathering. Electricians,plumbers, building maintenanceworkers, shop-fitters and carpentersare at risk if they carry out refurbishment,repairs, or maintenancework on buildings that contain asbestos.Other workers, not normallyassociated with the building trademay also routinely disturb asbestoscontaining materials without realisingit. For instance those installingcommunications networks, computers,alarms and interior furnishingcould also be at risk.Asbestos is still used to makevehicle brake pads, clutches, andgaskets. Mechanics removing andinstalling these systems should takecare, and also dispose of these itemsin sealed bags. High concentrationsof asbestos dust is also found in cityair where vehicle traffic is high dueto release from break pads.Some packing materials, anumber of fireproofing spraysand protective clothing and someplant pots also contain asbestos.In South Africa many people usepanel heaters made from asbestos.CONTROLLING ASBESTOS RISKAvoid new materials that containasbestos. Manufacturers shouldsupply a ‘material safety datasheet’ (MSDS) for their products.50The GreenHouse Project

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaAsbestos cont’dWhen choosing materials requesta MSDS and check it for asbestoscontent.If you are not sure if an existingbuilding has asbestos materials init, try to find the original buildingplans which should indicate whatmaterials were used. Look out formaterials, which are lightweightwhen they look heavy, and thosethat are very thin for their strength.If asbestos is in good conditionand not likely to be damaged orworked on, it is safest to leave itin place and introduce a managementsystem. If you decide to leaveasbestos that is in good conditionin place, make a note of where it is,for example on your building plansor other records and keep thisinformation updated. Setting up aregister of the location of asbestosmaterials in the buildings is a goodidea, but always be aware thatsome hidden asbestos may still bepresent.Friability refers to the abilityof the material to crumble. If theproduct is old or weathered its friablenature may cause the fibres tostart breaking apart, which allowsthem to become airborne and thuspose a danger to people. Actionmust be take if the material is damaged,frayed, cracked or scratched;the surface sealant is peeling orbreaking off; the material is becomingdetached from its base;protective coverings designed toprotect the asbestos are missing ordamaged, there are signs of waterdamage such as water stains or ifthere is asbestos dust or debris inthe immediate surrounding area.CONDITIONS THAT CAUSEDAMAGE OR DETERIORATIONTO ASBESTOS MATERIALSCAN INCLUDE:= Water damage= Ageing and deterioration ofbonding agents that hold theasbestos together= Vibration, cutting, grinding,sanding, impacting, striking,or destructive handling of anormally non-friable asbestosmaterialIf the asbestos is in poor condition oris likely to be damaged or disturbedyou will need to decide whether itshould be repaired, sealed, encapsulated(enclosed) or removed.REMOVAL OF ASBESTOSIf asbestos is likely to releasedust, cannot be easily repairedand protected, or is likely tobe disturbed during routinemaintenance work, it is best toremove it. Removal is the onlycomplete solution, but can be veryexpensive. Use only an expert todo this dangerous work.Removal tips= Workers doing the removalmust wear filtration masksand disposable or protectiveclothing= Take care not to expose otherunprotected people. Clothingand shoes worn during asbestosrelated work should remain onsite for laundering. All workersinvolved in asbestos-removalshould shower before leavingwork= Wet the material to decreasethe amount of fibres releasedinto the air. Never use a vacuumcleaner to remove asbestos dust= Make provision for the disposalof contaminated liquids= The materials should beremoved in sealed bags= Take precautions to preventbags with wet asbestos frombursting= Don’t break up large pieces ofasbestos materials= Never use power tools onasbestosas they create more dustDISPOSAL OF ASBESTOSIdeally asbestos containingproducts should be disposed of ata hazardous waste facility.ENCAPSULATIONWhere it is possible, it may bebetter to encapsulate asbestosrather than removing it andreleasing fibres in the process.Encapsulation is done bycontaining the entire area ina plastic enclosure that onlyallows air to enter. It is oftenthe best option when dealingwith insulation on heatingsystems. There are two typesof encapsulants. Penetratingencapsulants seep into asbestoscontainingmaterials and bondwith asbestos fibres. They havelittle impact on the outwardappearance of treated materials.Bridging encapsulating products,such as paint, coat asbestoscontainingmaterials with a moredurable surface. They are mostcommonly used to encapsulatepopcorn ceilings and furnace andheat duct insulation.Encapsulation is not a permanentsolution, although encapsulatingthe entire surface may offera longer-term fix. Asbestos can becontained, but the treated asbestosstill must be tested and possiblyremoved before a building isdemolished. If the area becomesdamaged, re-encapsulation or removalmust occur.ASBESTOS REGULATIONSIn South Africa, the National Centrefor Occupational Health (NCOH)is responsible for monitoring thehealth and safety of workers, includingworkers exposed to rawasbestos and materials containingasbestos. Obviously, the NCOH cannotbe everywhere at once – it is upto employers to ensure health andsafety in the workplace and up toworkers themselves to make surethat they are not exposed to hazardsat home and in the workplace.New asbestos regulationswere promulgated by the Ministerof Labour in the GovernmentGazette of 10 February 2002.Employers have a responsibilityto inform workers of the presenceof asbestos. The regulations makeit compulsory for employers toensure that workers are adequatelyand comprehensively informedabout the Regulations, and receivetraining in all aspects of workingwith asbestos.In June 2004 the minister madean announcement that new regulationswill be published soon toprohibit the use of asbestos. Forcertain products, where no currentalternatives are available, governmentwill allow for a three to fiveyear phasing-out period. x(For further information please referto research on asbestos atwww.greenhouse.org.za).Adventures and Lessons in Green Building 51

© The GreenHouse Project, Tel: +27 11 720 3773, www.greenhouse.org.zaFact sheet: Timber preservationThe first step in protectingtimber is to protect itfrom damage by insectsand dry rot.TYPICAL PRESERVATIVESTO AVOID:= PCP – A clear treatment, it is commonlyused to treat T&G boardingfor ceiling and floor boards. PCP orPentachlorophenol, is highly carcinogenic,and includes undesirablechlorinated substances, phenolsand solvent carriers. These will offgasat room temperatures and areparticularly hazardous for constructionworkers.= TBTO – A clear treatment, is oftenoffered by treaters as an alternativeto treatments which will discolourthe timber. Tributyle Tin Oxide, isa neuro-toxin and a known healthhazard. However what is not oftenrevealed is that it is mixed with thesolvent carrier Gamma Benzine Hexachlorideknown as Lindane. Thisis a deadly carcinogenic substance,which has been banned in Germanyfor over 40 years!= Creosote & Carbolinium – a darkoily treatment, includes between200 and 300 Petroleum compounds,many of which are V.O.C.‘s (VolatileOrganic Compounds) off-gassinghigh levels of harmful and carcinogenicsubstances.= CCA – Typically staining timber ashade of green, Copper ChromeArsenate has been found to leacharsenic into the soil and is highlytoxic if burnt. Concerns have lead toit’s recent banning in the USA.= Methyl Bromide/Bromomethaneis an insecticide often used to“doom fog” old buildings infestedwith borer beetle. While a provenhealth hazard and a suspected humancarcinogen, it is also an ozonedestroying substance.PYRETHRUM-BASED TREATMENTA plant based preservative, which canbe used to preserve seasoned timbers. Itis mostly used for paint-on DIY applications.While safe in its natural form, thereis still some debate around the safety ofits synthetically produced derivative.To speak to a supplier contactTimber Quest Fores-Tree, Tel: (021) 8457665, and/or Sommerset Timbers, Tel:(021) 845 8713.BORON-BASED TREATMENTA more environmentally safe ‘mammal-friendly’preservative is boron.(Mixtures of borax and boric acid aretraditionally used in powders, or insolutions widely used for eye washes,skin washes, urinary antiseptics andnappy rinses. Inorganic borates arenot carcinogenic or mutagenic).In spite of having SABS approval forover 50 years, its use is still fairly uncommonin South Africa. Its main disadvantageis that it is prone to leaching,which means that they are not goodfor burying in the ground or submergingin water. When used externally, it isimportant to apply further oil or waxtreatments such as “Outdoor” by EnviroTouch,Tel: (021) 556 1238.Some of the boron-basedproducts available on the localmarket= Totim B., Tel: 0800 411 200. Theagents are “Copper’s Arch”, PortEdward, Tel: (039) 682 6019.= Topro 94, Tel: (012) 664 1817/8.= Timbor, Tel: (039) 682 6019.= Timberwatch made by EnviroTouch,Tel: (021) 556 1238. An applicationfor seasoned timber which isrubbed on with a cloth or rag andcan be used to treat existing beetleinfestation.On-site boron-based treatmentFor small-scale operations, wheretimber poles are being harvestedlocally, Totim B is ideal. This borontreatment relies on the method ofsap displacement. As such the timbermust be cut as freshly as possiblewhen treating. Poles are cut andbrought to the dipping tank withtheir bark intact, where after they arestripped and immediately dipped inthe Totim B solution.If you treat your own wood youare meant to register with the SABS asa timber treater. This entails an inspectionby the SABS and a registration feeof approximately R600.Although this is an additionalcost, it does help ensure that thepreservation has been effective.Should one choose to treat withoutSABS certification, one must thenaccept any potential liability and one’sbuilding will not be compliant withthe National Building regulations.Boron treated timber suppliersIf treating your own timber is not feasible,ready-treated wood is availablefrom the following suppliers:= Somerset Timbers (Cape Town),Tel: (021) 845 8713.= The Pole Yard (Noordhoek & CapeTown), Tel: 789 2083.= Plett Timber Industries (PlettenburgBay), Tel: (044) 533 2404.= Houtbosloop Timber Products(Mpumalanga), Tel: (013) 733 4271.D.I.Y. TIMBER PRESERVATIONIn order to protect timber from dry rot,it is imperative to keep timber as dryas possible at all times with good roofoverhangs and protective footings.Various D.I.Y. methods do exist forkeeping insects at bay, though noneare SABS compliant.= Soaking the timber in water tode-starch the wood. Timber mustbe fully submerged for a min of sixweeks or until totally de-starched.The timber will look bleached.Starch is the food that insects areattracted to.= Harvesting the timber in newmoon (in winter) when the sapis at its lowest. This is an old Boermethod that was historically used topreserve poplar poles from insect attack.A tree surgeon once explainedto me that when timber is stressedit sends out natural anti-bodies toprotect itself from disease and insectattack. During late winter and at thetime of the new moon, is when timbertypically has the least amount ofsap and is at its most stressed.= Aloe Ferox is being used by KleinKaroo farmers as a substitute toconventional timber preservatives.The left over pulp from theAloe processing is used in a pressure-treatingtank to treat seasonedtimber. Being water soluble, it istypically only used internally.TIMBER FINISHINGAll timber, whether exposed to the elementsor not, usually still need somesort of treatment. We recommendnatural products such as EnviroTouch.(For further information please refer toresearch on timber preservatives in theGLAD Files on www.greenhouse.org.za).52The GreenHouse Project

ContactsThe GreenHouse ProjectPO Box 32025,Braamfontein, 2017South AfricaTel: +27 11 720 3773Fax: +27 11 720 3532Email: dorahl@ghouse.org.zaWebsite: www.greenhouse.org.zaCBS ArchitectsNow practising as James JacobsArchitects: (084) 351 9816Nic Whitcutt: Tel: (011) 482 7848,Cell: (083) 460 6052Sub-contractorsInvolved in the GreenHouse Projectpotting shed office renovationAfrica Glass IndustriesFor Anteloir Green laminated glassTel: (011) 607 4500Dirk BahmannFor rebuilding of GHP modelTel: (011) 805 3851Bathroom SpecialistsFor basins and plumbingTel: (011) 675 0990Blue Hills Hardware ccT/A S.A.W TimbersFor thatching laths (wattles)Tel: (011) 318 2420Enviro OptionsFor the EnviroLoo composting toiletsTel: (011) 708 2245EnviroTouchFor environmentally-friendly paintsTel: (021) 552 6834ESG Renewable EnergyFor solar water heaterTel: (012) 661 2501Freedom HardwareTel: (011) 493 7872Glow ElectricalFor electrical maintenanceand installationTel: (011) 970 1510 or 975 5593L.A.M WoodworksFor supply of wooden fixturesTel: (011) 402 9023Liebermann Pottery & TablewareFor basinsTel: (011) 482 2215/7Lindros WholeEarth ConsultantsAdvisors in organic agricultureand wastewater cleansingTel: (011) 467 0081Marmernova & 7 Building ProductsFor granite and marble kitchen topsTel: (011) 455 4422OrejenFor recycled timberTel: (011) 888 6811Rocha’s Paint & Building SuppliesFor cement bricks, stones and sandTel: (011) 624 1004/9David RossouwArt & Artifice for AfricaFor burglar bars on windowsand light fittingsTel: (011) 614 0217/6205San Afrika Cash ‘n CarryFor sink mixers etc.Tel: (011) 792 2104Sun Timber SalesFor SA pine supplyTel: (011) 474 2544/5/6/7Superior InteriorsFor timber fittingsTel: (011) 342 6521ThermguardFor cellulose insulationTel no: (033) 346 0111Tridarc OrangeFor manufacturing of burglardoors and metal skirtingTel: (011) 433 2210Helene van der MerweFacilitating straw-balelearn & build workshopTel: (012) 993 4339Constructionmaterials scrapyardsMarco Boni Building EnterprisesTel: (011) 618 3090Tudu ConstructionTel: (011) 618 4755 or 614 9873DonationsAfrica Glass IndustriesxArts Culture and NationalHeritage Distributing Agency(the National Lottery Trust)xBritish AirwaysxCanada FundxCity of JohannesburgxThe Development Bankof South AfricaxEnnertron solar geysersxEnviro OptionsxMr. and Mrs. GrealyxInternational WaterSecretariat/Lindros ConsultingxPPC CementxMr. Sumner SwanerxThermgaurdxMr. and Mrs. WahlAdventures and Lessons in Green Building 53

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