Designers of beddington zero energy development, a housing complex about 20 kilometers from the center of London, have taken on the challenge of transforming suburbia.

Within its five blocks of terraced buildings and gardens, the development, nicknamed BedZED, includes 82 homes, 18 mixed work living units and 1,560 square meters of pure workspace. Its density is about 400 habitation rooms and 200 jobs per hectare. If that density were replicated throughout the U.K., it would cut urban sprawl by 75% and eliminate the need for development of greenfield sites, claims Bill Dunster, the project's locally based architect.

Along with efficient land use, project goals include energy efficiency and reduction of carbon emissions. The inclusion of workspaces reduces the consumption of fossil fuels and the production of emissions from commuting. Future addition of 40 communal electric cars charged by solar panels also is planned.

WIND DRIVEN Vents supply fresh air.(Photo courtesy of ARUP/Graham Gaunt)

Designers claim that BedZED's heating demand will be 90% below the requirements of national building regulations. For example, homes have no artificial heating. Instead, solar gain through expansive south-facing windows and human activity provide heat, says Chris Twinn, Associate Director of Arup Ltd., the project's London-based design engineer.

To store heat, designers went for thermally massive structures, using mostly masonry and concrete rather than wood, triple glazing and high levels of insulation, says Twinn. At 30 centimeters, the wall cavity insulation provides more than three times the insulating values of typical residential construction, he adds. Wind-driven roof vents draw in fresh air and eject exhaust. Heat exchangers between the two air streams warm incoming flows.

An onsite cogeneration plant fueled by chipped tree waste provides hot water and electricity for the whole complex and heat for work spaces. The plant is designed to deliver 130 kw of electricity and 200 kw of heat.

HOT HOUSE Solar gain warms interior. Photo courtesy of ARUP/Graham Gaunt)

Among other green features is the site's wastewater treatment plant, which will use reed beds to produce effluent suitable for watering gardens and flushing toilets. Trying to convince permitting authorities of the effectiveness of the autonomous wastewater system was one of several culture clashes with local officials, says Twinn. The municipal sewer connection forced on BedZED will lie idle, he adds.

The $17-million project earns praise as an investment from its developer, the not-for-profit Peabody Trust, London. About one-third of the units are rentals, with the remainder almost all sold. Construction is now nearly complete, and Peabody expects the complex to be fully occupied by early summer. According to Adrian Panucci, Peabody spokesman: "The response from the public has even taken Peabody by surprise."