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

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