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Solar buildings in Gårdsten - Gårdstensbostäder

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SOLHUSEN IGÅRDSTENolar buildings in Gårdsten


The creation of Solar buildingsin Gårdsten is a story withmany dimensionsTHIS IS A STORY ABOUT TECHNOLOGY AND HOUSING RENEWAL.Solar buildings, Solhusen, has become renowned as an example of propertyrenovation with energy solutions based largely on solar heating.THIS IS ALSO A STORY ABOUT COLLABORATION BETWEENEXPERTS AND LAYMEN. It is about how a housing company succeeds inmobilising the tenants’ inventiveness and how they can then act as asource of inspiration and ideas for both architects and building engineers.AND IT IS ALSO A STORY OF PERSISTENCE. To in one and the samerenewal project reduce future maintenance and energy use, cut livingcosts, apply modern recycling technology and achieve new aestheticvalues requires a persistent initiator and a strong belief in the capacity ofthe individual.


SolhusenRenewal andresidentialinfluenceThis brochure is intended to highlight the creation of Solhusenfrom all these points of view. But first a brief description ofGårdsten and the background to the renewal process.Gårdsten is a “million new homes programme” area datingfrom the early 1970s. It was in considerable need of renewalwhen Gårdstensbostäder, founded in 1997, purchased some2,000 apartments in the area from Bostads AB Poseidon andGöteborgs Stads Bostadsaktiebolag and many of the apartmentswere vacant. Today, Gårdstensbostäder has also


acquired around 700 apartments in Norra Gårdsten(previously apartments owned on a co-operative basisand apartments under private management) and consequentlyit manages all the rented apartments inGårdsten.The management also included development – tocontribute to the overall transformation of the areaand ensure that it becomes a better area in which tolive.The latter is possible only if the residents themselvesare involved to a significant extent in thedevelopment process. Each change has been precededby discussions and collaboration with the tenants andthe results achieved – improved commercial services, areduction in vandalism, a more pleasant environment,new jobs for the unemployed – have shown both theresidents and others that local collaboration has beenmeaningful.The inception and care of Solhusen are thebest proof of all.


From grey concreteBeforeThe first Solhus area, Solhus 1, comprised threeblocks with 255 apartments and was renovated as aturnkey project with Skanska as the main contractor.Preparatory work commenced in spring 1998 and inMarch 2000 the first tenants could move in.The project’ssecond phase, Solhus 2, was completed inautumn 2003. Solhus 2, which was completed as anumber of sub-contracts, essentially comprised thesame number of apartments, with in principle thesame (exterior) measures taken as the original Solhus1 with a five-year performance guarantee.With advanced plans to combine renovation withsolar heating, Gårdsten was included in the EU projectSHINE for Solhus 1 and Regen-Link for Solhus 2,which offered certain financial support from the EU tocover some of the additional costs.As an EU project,the Solhusen buildings were subject to particular technicaland architectural stipulations. At the same time,it facilitated more extensive preliminary studies andenquiries than would normally have been the case.The name Solhus (“Solar buildings”) was chosento emphasise the focus on the future, with thereconstruction of a “million new homes programme”area where use of solar energy was one of severaltechnical measures employed.The focus also includedGårdstensbostäder’s wish to keep rents low and make


locks…BeforeBeforePhoto ©Christer Nordström Arkitekter ABit possible for the tenants to influence their costs(with the help, for example, of individual metering ofspace heating, electricity and water use). Gårdstensbostäderalso had the ambition to trim costs byreducing the number of stages in the constructionprocess.This ambition had cut costs by SEK 20 millionby the time Solhus 2 was completed in the form of31 smaller, “tailored” contracts.The buildings were constructed using prefabricatedconcrete elements and have flat roofs.There are twotypes of buildings: buildings with access balcony walkwaysand three or five floors above ground, withan external staircase leading to entrances from thewalkway balconies, as well conventional slab buildingswith entrances on the ground floor and internalstaircase leading to three floors, including the groundfloor. The balcony access buildings have balconiesfacing south along the whole building and the slabblocks have recessed balconies facing east and west.The blocks were supplied with heat from districtheating and they were fitted with mechanical supplyand exhaust ventilation.The tenants paid rent thatincluded heating and electricity and consequentlythere were few incentives to save energy.


…to open, bright “Solar buildings”The balcony access buildings were fitted with roofintegratedsolar collectors which, via accumulatortanks in the cellar, pre-heat hot water in the block.The balconies in the balcony access buildings wereglazed to protect the facades, reduce heat loss andimprove the balconies. During spring and autumn,the sun shining on the balconies pre-heats the ventilationair for the apartments. The open groundfloors of the balcony access buildings at Solhus 1 havebeen replaced by greenhouses for the tenants andnew, bright laundry rooms and rooms directly adjacentto the greenhouses, which can be used by thetenants. In addition, compost machines transformhousehold waste into soil, which can then be used inthe greenhouses.


New energysolutions combinedwith renovationThe proposed general measures, produced in collaborationwith the tenants, were complemented anddeveloped during the project’s enquiry and systemphase.To provide system documentation a basic alternative,in most cases covering mainly necessarymeasures, was compared with a more expensivealternative, which entailed energy savings within abudget for additional investments.The project finally came to include carefully plannedrenovation where the majority of the additionalcosts for energy measures are covered by the reductionin operating costs.The energy-related measurescan be summarised as follows:· Conversion to exhaust air ventilation in the balconyaccess buildings and the installation of heat recoveryon ventilation in the slab blocks· The glazing-in of balconies in connection withrenovation (damaged concrete elements)· Replacement of the inner windowpane by low emissionglass in the existing double-glazed windows· Solar collectors integrated into the roof inconnection with roof renovation· Additional roof insulation in connectionwith roof renovation· Additional insulation of the gables in connectionwith facade renovation· Insulation of the bases in connection withrenovation of the drainage system· New washing machines and drying roomequipment connected to the hot water system· New energy-labelled white goods as partof the refurbishment of the apartments· Installation of presence-controlled lightingin the common areas· Installation of a central control andsupervisory system· Introduction of individual metering forelectricity and heating as well as hot and coldwater


In addition, the buildings were given new laundryrooms and common areas, greenhouses on theground floor in the balcony access buildings andnew rooms for ventilation units on the roofs of allthe buildings. The entrances and stairwells havebeen renovated and the whole area has been givena new colour scheme and external lighting. A newtype of waste-handling system has also been introduced,with sorting at source (a new facility besidethe car park) and composting (beside the greenhouses).Wastechutes and rubbish rooms are nowbeing used for other purposes.Illustrations ©Christer Nordström Arkitekter ABBUILDINGS WITH DOUBLE FACADES/ENVELOPESThis building has solar air collectors on the southernfacade.The walls to the north, east and west have beenfitted with extra insulated facades outside the existingwalls. In doing so, a cavity was created between theexisting walls and the new facades where the heated airfrom the solar collectors is circulated by a fan.BUILDING WITH SOLAR COLLECTORSON THE ROOFWhen the sun shines on the solar collectors the liquid(glycol mixed with water) inside the collectors is heatedup.The liquid is transported down to the accumulatortank in the cellar with the aid of a small circulationpump. The warm liquid heats up the water in thetank, and the tank is used to heat the hot waterused for washing dishes and clothes, baths etc.


Result:Major savingsThe follow-up through to 2004 has shown that operatingcosts have been cut by reducing the buildings’heating, ventilation and hot water requirements by45%, from 5,000 to just over 2,700 MWh/year.The graph on the next page shows the resultsfrom the follow-up of heat supply, use of electricityand water use:· district heating requirements (corrected fortemperature variation) have been reduced fromjust over 270 to approximately 145 kWh/year/m 2· electricity use is reduced from approximately50 to 35 kWh/year/m 2· water use is reduced from 2.36 to 1.63cubic metres/year/m 2The collective metering of electricity, water andheating has been changed to individual metering, whichmeans that each tenant can influence the cost ofelectricity, water and heating, which has also contributedto reducing operating costs.EACH APARTMENT HAS JUST OVER SEK5,000 LOWER OPERATING COSTS PERYEARThe additional cost for the operating and energysavingmeasures that have been made amount toapproximately SEK 20 million, of which just under30% is covered by a contribution from the EU andthe Swedish Energy Agency.Since the tenants moved in savings have increasedeach year due to the tenants’ actions, as it has provedadvantageous to be thrifty. However, the cost of purchasingdistrict heating, electricity and water increasedduring the same period.In 2001, the saving was approximately SEK 1.0million and in 2004 approximately SEK 1.6 million.During the period 2001–2004 the total saving wasapproximately SEK 5.3 million, which is just over SEK5,000 per apartment per year.MEASUREMENT OF HEATING, WATERAND ELECTRICITYSpace heating, or rather the thermal comfort, ismetered by means of room temperature measuredin the living room and bedroom. The temperature


measurements are transmitted from this sensor to amemory in the stairwell. The information from thismemory is then passed on to a receiving station,where all the measurements are processed.The finalresult shows how warm it is in the apartment andwhat the tenant will pay.The tenant decides on thetemperature in the apartment with the aid of thermostatson the radiators. The basic rent is basedon a temperature of 21 degrees. If the tenant wantsit warmer it will cost extra and if the tenant wantsit cooler there will be a rebate.Similarly, the measurement of cold water and hotwater takes place using flow meters and an electricitymeter.All information is transmitted automatically to areceiving station for compilation.The rent is adjusteddepending on whether the tenant uses more or lessthan what is included in the basic rent.Radiator thermostatTemperature sensor5,000“Savings” Water cost Electricity cost District heating cost4,0003,0002,0001,0000Before 2001 2002 2003 2004


The tenants are very muchinvolved in the changesThere are many factors to be taken into account– the EU project’s requirements, the assessmentsof building experts, Gårdstensbostäder’s ownexpertise and conditions – but first and foremostthe tenants’ wishes and views. The aim was thatthese should be the controlling factor in the process.Interest in being involved was initially lukewarm.Many tenants were sceptical about whether theycould actually influence the work. They were reluctantto move into replacement apartments in thearea that were offered during the reconstructionwork. Methodical mobilisation was required to getthe tenants involved.INTEREST-AROUSINGINFORMATION APARTMENTAn information apartment, strategically located inthe heart of the area, was set up.The apartment wasrefurbished to the standard that was envisaged as anorm for the area and included models and informationmaterial.In the information apartment it was possible todiscuss with the tenants in more depth than at themore customary tenant meetings. In the “livingroom” there was a graffiti wall with the heading “Wewant” and a heading “We do NOT want”. The writingon the graffiti wall increased steadily and gaveGårdstensbostäder a solid foundation for the project.TENANT CONTACT INSEVERAL STAGESA meeting at which the reconstruction plans werefirst presented was attended by 80 tenants. Around20 of them stated that they were willing to take partin the envisaged project working groups.In the next stage, the inspection, each tenant wasvisited by a project manager responsible for tenantinfluence and an inspector. It emerged that the vastmajority were positive about the reconstruction.In a packed meeting hall there are many people whoare reluctant to put up their hand and say what theythink but the personal contact during the inspectionstage led to 74 tenants indicating an interest in beinginvolved in the eight working groups. Of these, 54became permanently active in the ensuing work. Thiswas in an area with 150 households.


WORKING GROUPS’ PROPOSALSThe working groups were made up of interestedtenants with the project manager responsible fortenant influence as a source of inspiration and convenor.Experts from the project management and otherspecialists were invited to the groups as necessary.The groups formulated proposals and a basis forwhat the tenants wanted the renovation to result inwas created. This was based on the material thatemerged at the information apartment, at the tenantmeetings and during the inspections.THE SECURITY GROUP submitted proposalsfor a new lock system and an entry system withcards, which would operate both the entrance dooras well common areas. The group also wanted newentrance doors in the galleries as well as entryphonesand better lighting.THE APARTMENT GROUP produced a detailedproposal for how the apartments should be renovated.THE WORKING GROUPS FOR THE NEWGROUND FLOOR, UTILITY ROOMS ANDTHE ENVIRONMENT rejected the architect’sfirst proposal and instead, in consultation with thearchitect, they formulated a further proposal for howthe new ground floor should be designed.They wantedthe utility rooms on the ground floor with a viewover the outdoor areas, large windows, automaticlighting and a new booking system with cards. Theutility rooms should be located directly adjacent tothe greenhouse and the public rooms.The group alsoproposed a new waste-handling system with compostingand a new system for residual waste. For theground floor, proposals were formulated for premisesthat could be used by all the tenants in the block.THE WORKING GROUP FOR THEEXTERIOR ENVIRONMENT compiled theviews from the information apartment and theinspection and reported that refurbishment wasnecessary.The group were agreed that refurbishmentinitially should make the areas outside the buildingsinto good play areas for small children. The tenantswere even involved in the colour scheme – theywanted to do away with the feeling of grey concrete.The Building Committee approved a model with anew colour scheme facing inwards towards the outdoorareas where the tenants moved around andfacing outwards the facades were painted in a light,uniform colour to retain the original facade image.THE WORKING GROUP FOR CAR PARKSAND TRAFFIC put together basic documents thatwere centred on the fact that the residents wantedfresh-looking, secure garages and outdoor car parkswithin view of the apartments.THE WORKING GROUP FOR AERIALS,SATELLITE DISHES AND IT wanted an IT-linkto the apartments and a satellite dish or a commonlocation for their own satellite dishes on the conventionalslab buildings.When the reconstruction and renovation workhad been completed several of the old tenantsmoved back. Other apartments quickly acquired newtenants.The building managers sent out invitations tomeetings dealing with the exterior environment andthe tenants continued to show an interest in theirarea. Together with the building managers and a


Mobilisation followingre-occupationlandscape architect they drafted a proposal for newplay facilities and flowerbeds and a fence aroundtheir own outdoor areas facing the paths. AtEkgården an old football pitch was converted into anarea for boulesMANY OF THE TENANTS’ PROPOSALShave been implemented in conjunction with thereconstruction.The involvement and interest from the rebuildingphase has continued.The tenant meetings have beenwell attended and the tenants have been involved ina range of different projects.At Aspgården the tenants have on their own initiativetaken over the cutting of the grass and clearing ofweeds so that they have the flowerbeds they wantand to save money for the rest of their outdoor area.The outdoor area committees have also createdcommon areas.At Aspgården the tenants have paintedand equipped a children’s room for games, crafts andother things. The room can also be used by thetenants for children’s parties and similar activities.Another room has become a table-tennis room. Atable-tennis room has also been arranged atSyrengården.


Awards forSolar buildingsThe project has attracted considerable attention both nationally andinternationally, with a whole range of education visits and newspaperarticles in the daily press and trade magazines.Building of theYearIn 2000, the project wasnominated in the constructionindustry competition“Building of the Year” in theclass “Renovation Project ofthe Year 2000”.Energy PrizeThe method for individualmetering of heating led tothe Energy Prize for 2002.Best ColourSchemeIn 2001, the project wasone of the winners in theMaster Painter’s competitionfor “Best ColourScheme”.World Habitat AwardWas recieved 2005 in Jakarta and presented by brittish BSHF (Building and SocialHousing Foundation) in cooperation with UN Habitat.


FACTFILE:NUMBER OF APARTMENTS: 255LIVING AREA: 18,720 SQUARE METRESPRODUCTION COST: SEK 105 MILLION(equivalent to SEK 5,608 per square metre)OF WHICH THE PRODUCTION COST FOR ENERGY-RELATED MEASURES: SEK 20 MILLION(equivalent to SEK 1,068 per square metre)REDUCED ENERGY COST 2004: SEK 1.6 MILLION(equivalent to just over SEK 6,000 per apartment)


SFacts aboutGårdstenNumber of residents: approximately 7,000Location: 13 km northeast of the centre of GöteborgHeight above sea level: 100 metresNumber of homes: 3,038Of which municipal-owned rented apartments: 2,694Construction period: 1969 – 1972Currently under construction: 44 semi-detached dwellingsPlanned: 150 – 200 single-family dwellingsTowardsKungälvTowardsAleSolhusenTowards VolvoVästraGårdstenÖstraGårdstenBäckebolköpcentrumTowardsGöteborgGÅRDSTENSBOSTÄDER · Kastanjgården 3 · SE-424 39 AngeredTelephone: +46 (0)31-332 60 00 · Fax: +46 (0)31-332 60 01E-mail: gbg@gardstensbostader.goteborg.se · www.gardstensbostader.se

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