In London and other UK cities, the major problem in accommodating the DETR's target is land. Vacant areas are scarce and of poor quality – mainly brownfield sites.
One scheme designed to tackle the problem has just been awarded outline planning permission. The Beddington Zero Energy Development, BedZED, will make use of a former sewage works in Surrey for a combination of housing, shops and workspaces.
Just as important as the type of land used is the way it is being transformed in this scheme. The BedZED designers looked at current and potential future problems of energy and land use, and the changing ways people live and work. They want the scheme to become totally sustainable and non-ozone depleting. Therefore, while maximising space use was vital, the servicing determined its final shape.
The project was initiated around five years ago by architect Bill Dunster and Chris Twinn of Ove Arup & Partners. Developed by the Peabody Trust with environmental organisation BioRegional, the scheme will create up to 100 homes and 1800 m2 of workspace. Contract tenders are due for November, with the main contractor due on-site in December 1999.
Peabody was only the second highest bidder for use of the site, however on DETR approval, the council could consider the environmental benefits of the tender – the first time this has been authorised.
The scheme is designed to reflect existing local styles. Use of local materials and commodities will be maximised – building materials will be chosen from renewable or recycled resources and sourced, wherever possible, from a 35 mile radius of the site to reduce transportation energy.
Internet access will be provided to reduce the need for travel off-site. On-site facilities, as well as workplaces, will include an organic grocery store, nursery and health centre. In theory, the scheme appears to mimic the new town developments built earlier this century as individual, self-contained communities.
All energy supplied to the site will be from renewable sources, with no fossil fuel use.
The layout of the buildings is designed to maximise solar energy gain for heating and lighting. They consist of blocks of south-facing living areas, with low level workspaces on their northern side (see figure 1).
Offices will be daylit by indirect northern light through the atrium and skylight – minimising computer glare and helping to prevent overheating.
The combination of solar, people and appliance heat gain, triple glazing and super-insulation (designed to 0·1 W/m2K) should remove the need for conventional heating. Heat regulation will be provided by exposed high thermal capacity room surfaces.
The areas are designed to a high level of air tightness with an air change rate of 0·1ac/h. Heat from domestic activities which would otherwise go to waste is therefore used to form part of the natural heating system.
With such a low rate of change, ventilation was a concern. However, a natural solution for this is also being applied – use of the passive stack effect and heat recovery.
Domestic hot water will be heated by a 100 kWe biofuel chp plant, initially fuelled by tree surgery waste. The scheme will be connected to the national grid to enable matching of the constant chp output to demand.
In addition to the buildings, an adjacent landfill site will be reclaimed to create a working ecology park with over 50 acres of lavender fields, wetlands, community forests and green space. This could eventually supply BedZED with all the fuel it needs.
Water conservation is also high on the agenda. Mains water will be connected for drinking water and washing only. Rainwater and grey water will be used for toilets.
Transport is seen as one of the biggest energy consumers and it is unrealistic to assume residents will never need to travel off-site. With this in mind, one proposed solution involves using photovoltaics to fuel an electric car pool. An EC-funding application for a building-integrated pv array has already been made.
On top of being totally sustainable, if the BedZED scheme is successful it could stand out as a net producer of renewable energy.
Source
Building Sustainable Design
