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Sustainable HousingSustainable housing has thepotential to produce goodquality housing at a price thatis affordable both in the shortand long term. The concept of sustainability (meeting theneeds of today withoutcompromising the needs of future generations) has beenaround for a number of yearsnow, however its applicationto housing has been slow. Those projects thathave been undertaken tend to focus largely onproducing ultra-green housing that is extremelyhard to reproduce as mass development projects.

A truly sustainable housing project shouldincorporate economic, social and environmentalissues in the planning and design stages with theaim of providing a building that is affordable,accessible and environmentally sound. It goeswithout saying that compromises will have to bemade, but the result is a project that can be appliedto the mass housing market, where the greatestenvironmental impact lies.

The requirement for new and upgraded buildingsin the UK is massive and it would be preferablefor these new buildings to follow a sustainablepath to reduce the long-term environmentalimpacts associated with such developments.

This guide provides a background to what isinvolved in building a sustainable house orhouses.

Planning the ProjectThe planning of a housing project initiallyinvolves communication and interaction betweena variety of parties. These parties should include acomponent of environmental expertise. Due to theexpert advice and assistance now available itwould not be impossible for a developer to

produce a sustainable building(s) without the

assistance of an environmental specialist howeverit would be advised that there is environmentalexpertise available throughout the project.

It is desirable that a forum is created fordiscussing all the options that are open to theproject. Ideally the forum group will consist of the builders, the structural/civil engineers, thearchitects, the quantity surveyors and of course thedeveloper. It is likely that the developer will havea general idea as to what they wish to be

constructed and it is from this point that the forumcan move forward.

A forum should encourage the active participationof all members of a design team with regards tothe discussions regarding material choice. Thisparticipation will prove essential in ensuring abalanced view of materials. For example, aninexpensive material that has excellent

environmentalperformance maybe inappropriate foroperational reasons.

This may be something that is obvious to thedesigners but may not be so crystal clear to anenvironmental scientist. Conversely, materialsthat are routinely used in construction may haveenvironmental issues that would not have occurredto other members of the design team. In thesesituations the forum acts as an informationexchange but it has also is useful in situationswhere there is a delicate trade-off between thethree criteria so that the best overall (sustainable)option can be chosen.

If the project wishes to be accredited to anenvironmental standard, such as BREsEcoHomes, it is good practice to use it as an initialframework for planning the project as this willhelp the project gain the highest possible rating.As with all standards for sustainable design, theprioritisation of issues may not be in agreement

with your own, however there is the opportunityfor obtaining some easy credits, gained by

A background to running a sustainable housing project

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making simple changes to the design at minimalor no cost.

Building DesignThis is a major decision in any development,particularly where sustainability is an issue, as thedesign of the building will play a major role indictating the building materials used. The designof a building is generally decided andsubsequently the materials selected that arerequired within the job, however if specificbuilding materials are to be prescribed it issensible that these are highlighted. Certain goalsshould be set out early on especially the longevityof the building. Most buildings are currently onlydesigned to last 60yrs.

The structure of the building will be a major issuein the sustainability of the materials required forconstruction. Ensure that the structure that isdecided upon is going to have a durableframework but also has the potential to be easilyremoved at the end of its life.

The energy use of the building will depend on theefficiency of the insulation and also the way in

which the insulation is fitted. Thermal bridging,where two building elements meet, should belooked at closely as these areas can be majorsources of heat loss. The way in which a buildingis heated is important. If you are increasing theinsulation of a building you can decrease theheating requirements. Dont forget to take intoaccount solar gain and also the heat given off byhousehold appliances. Renewable sources of power should be investigated as these may be ableto provide either heated water or actual power for

appliances.

Electrical goods (primarily white goods) have thepotential to consume large volumes of power,therefore select goods on their energy efficiency.Light fittings can be selected that will dictateenergy efficient bulbs.

It is important to ensure that the outsidetemperature, through insulation, does not undulyinfluence the building although it is equally asimportant the building is adequately ventilated andalso receives sufficient daylight. Heat exchange

extracting fans can be used to good effect inbathrooms and kitchens to ensure that the heat isnot all lost to the outside.

The security of the development will play a major

role in making the development desirable to livein. This is not only influenced by locks andintercoms but also by lighting and design. Accessfor all if influenced by door width and also stepsand similar. Aspects of the development whichinfluence how the new project will integrate intothe existing community should be examined suchas the capability of local facilities to support thedevelopment.

Building MaterialsThe materials that are used to construct thebuilding will have a major influence on all aspectsof the construction. Look at the cost of thebuilding material from a number of angles, as acheaper option may save money in the short termbut require greater maintenance or have a shorterlife-span resulting in greater expense in the longterm, and with it greater environmental impact.More sophisticated insulation may cost slightlymore now but over the lifetime of the project may

produce significant savings in heating costs.Furthermore materials that are marketed as moreenvironmentally sound may actually represent agreater risk through application of chemicals forimproved performance or maintenance.

If the site requires demolition prior to the initialdevelopment, the possibility for re use as fill orfoundations should be investigated. Ideally, anysoil that is on the site should be protected on siteto reduce the need for soils to be brought in.

Contamination on the site should be remediated towithin guidance values, if possible, with theminimum amount being put to landfill, with onsite remediation techniques being investigatedwhere applicable.

Try to source materialslocally to support the localeconomy and also to reducethe amount of transportationrequired. Perversely,transportation by sea, by

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weight, is by far the most energy efficient.

Timber will be one of the major materialsinvolved in any building job. It is an idealbuilding material for its strength and ease of

shaping. It also has the potential to be a fullysustainable building material. Ensure that whenwood is purchased it is known that it issustainably harvested. The FSC certification isone of the most rigorous checking system fortimber. It ensures that the forests from whichtrees are taken are sustainably harvested and alsothat forests are replanted. Other standards existsuch as Forests Forever which ensure that trees arereplanted for those that are harvested. Ensure thatthe information that you are provided with isgenuine, as many countries are still exportingtimber with little regard for the environment.

Timber treatment is not always required. If thetimber does not need to be treated withpreservatives then there may be no real need.Various varieties of trees have timber that can beused without any form of treatment in exposedsections (eg Douglas Fir). Timber such as this canbe used for cladding or even as roof tiles.

The blocks used in construction can be made frommaterials with a recycled content (85-90%). It issometimes sensible to ensure the quality of theproduct by buying block with lower recycledcontent. Most other aggregate based products canalso be obtained with a high percentage recycledquotient.

Insulation material can be foundthat are made from 100% post

consumer products. Theperformance that they offer isequal to that of Glass Fibre but isgenerally more expensive.Additional costs may be incurredwhen using post consumerproducts for insulation in the formof time or else boarding. Though itis desirable for post-consumerproducts to be used, economicsmay dictate the use of standard

insulation. The environmentalimpacts of Glass Fibre products, if

properly managed, are not significant compared tothe benefit that the product offers within thebuilding.

Plastics are liked for their flexibility and also for

being lightweight. Various plastics have gainedbad reputations for the pollution created duringproduction and also for releasing chemicals intowater. Most plastics can be recycled, to an extent,at the end of their useful life. Plastics should notinstantly be discounted for use within sustainablebuildings, however investigations should be madebefore they are used.

With regards to metals each has its ownadvantages and disadvantages all of which shouldbe taken into account. Durability and the abilityfor recycling are the primary advantages whereascost and weight are the disadvantages. Iron andsteel will require to be coated to protect them fromthe elements that is an additional cost that shouldbe calculated for.

At the end of the buildings life it is desirable thatthe building may be dismantled easily forrecycling or re-use. Screws allow for timber to beremoved far more easily than nails and also limemortar can more easily be separated from bricksthan cement. Both screws and lime mortar willrequire extra time during construction whichshould be calculated for.

Construction PhaseThe construction phase will be the busiest phase inthe buildings life and with this, increased risks of environmental impact, complaints and loss of money. It is important that the impact of this is

minimised. This is also going to be the firstcontact with the local community so it isimportant that the disturbance created isminimised.

Each phase of the construction should be plannedout in detail with a site plan issued to allcontractors informing them of the locations forstorage and waste disposal, drains, fuel and otherissues. This plan may have to be changed anumber of times over the life of the project but itis essential to maintain a well-organised site tominimise accidents, risks and damage to materials.

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Waste segregation has the potential to savemoney. Inert waste has a far lower land fill costthan active waste and wood waste will becollected for minimal or no cost by some

companies. This requires skips to be on site atany one time, which on city centre sites mayalmost be impossible due to space restrictions.Further segregation of waste may be possible if space is available. It isimportant that proceduresare developed andcommunicated to allparties on site to ensurethat they are aware of forexample the differenttypes of waste generatedthe risks associated with it and the mechanisms inplace for reducing these risks.

Additional benefits relating to having a dedicatedstorage area includes the reduced risk of damageto materials prior to use. Materials that are takenout and not used should be returned to this area toprevent materials stored at random around the site.

Oils, diesel and other chemicals should be storedin bunded areas that comply with Health, Safetyand Environmental Legislation and otherrequirements and if diesel is regularly beingtransferred to plant or machinery, a bundedtransfer area should also be created. The sitemanager should be provided with spill kits forboth chemicals and oils so that any spills that dooccur do not create contamination on site.

Handing Over to the Occupier

When someone buys any piece of electricalequipment they are provided with a detailedinstruction manual that explains how eachcomponent works. Though few people read thisguide cover to cover it is generally kept and usedas a reference when and if problems occur.

A new house or development of houses should beprovided with an instruction manual that explainshow all the appliances work, locks are used androoms ventilated. The document can also be usedto explain how to reduce power consumption andalso to increase the warmth within the building. A

list of local shops and services will serve theoccupier and community well and reduce the timeit takes for new residents to be integrated into acommunity.

Providing appropriate bins for the new owners andalso the location of the nearest recycling facilityshould encourage recycling of household waste.

To prove the success of the building project it maybe desirable to monitor the power consumption of the houses once the tenants have moved in. Thisinformation can be compared to otherdevelopments that are not as sustainable to provethe long-term economic benefits of a properlyinsulated building.