We need to create greener housing on a large scale. But apart from a few photovoltaics and chp projects from housing associations, nothing much is happening. What will it take to make housebuilders get with the sustainability programme?
Some 140 000 new homes are built in Britain each year, but the number using anything other than conventional energy sources runs into just hundreds. While countries like the US and Germany have large-scale programmes to put photovoltaic panels onto buildings, the sight of a photovoltaic panel on a British house roof remains such an oddity that it is likely to draw curious glances from passers by.

The few new homes that are built to use energy from renewable sources are often the product of a housing association, keen to demonstrate a more environmentally-friendly way of housebuilding and reduce energy bills for their low-income tenants. Meanwhile the bulk of new homes, those sold for the mass market, continue to guzzle the gas, pump out the CO2 and at the same time are being packed with ever more energy-using gadgetry in the form of domestic appliances, home entertainment systems and IT.

None of this is helping the Government to deliver its energy-saving objectives, specifically its commitment under the Kyoto Protocol to reduce greenhouse gas emissions by 5% on 1990 levels by 2010 and have 10% of the country's energy demand met by renewable sources. And with technology like photovoltaic panels being much easier to fit to new homes than they are to existing ones, opportunities are clearly being missed.

Housebuilders are not totally ignoring environmental concerns. Energy saving boilers and extra insulation are going into new homes, while the buying public's desire for light, space and big windows is allowing architects to exploit passive solar gain. But when it comes to integrating technology like photovoltaic panels, wind turbines or combined heat and power (chp) plant into residential schemes, there are strong reasons why housebuilders are reluctant to do their bit for the Kyoto Protocol.

Prime among the obstacles to adopting renewable energy is cost. The Building Centre Trust will shortly publish a report which supports renewable energy, Renewable Energy in the Built Environment. The report states: "As a rule of thumb for consumers at prices in 2001, the cost-effectiveness of energy efficiency – reducing consumption – is greater than the payback achieved by employing, say, photovoltaics to generate your own electricity."

"Had we not got a DTI grant to provide photovoltaic slates, I doubt we would have done it because the payback time is so horrendous," says Mark King, technical development manager of Laing Homes on the housebuilder's recent application of the technology on homes in Edmonton, north London. The 2 kW of photovoltaic slates fitted onto each home at Edmonton cost around £15 000 and have a payback period of 75-80 years. The DTI grant paid a substantial share of the cost of the slates, with buyers being charged a premium of around £5000-10 000 on their homes. Irrespective of the premium, homes sold quickly and there was so much interest in the technology that the housebuilder built a special viewing platform for visitors to the site. "But I don't believe that people bought because the homes had photovoltaics," says King. "I think they bought because of the market."

Nonetheless, Laing is not giving up on green power after this trial. "We intend to follow the solar roof slate initiative with a range of projects that will promote and encourage sustainability," says Laing Homes chief executive Steve Lidgate.

At London's Greenwich Millennium Village (GMV) various energy options are being explored in a bid to reduce primary energy consumption for a typical home by 80% (see factfile 'Two approaches to chp'). GMV's developers, a consortium of Taylor Woodrow Capital Developments and Countryside Properties, set themselves this demanding target as part of a set of objectives that would establish this 1377-home development beside the Millennium Dome as a sustainable community.

Both photovoltaics and wind turbines have been considered, but both will only play a small part in powering this major London housing scheme. Most wind turbines are confined to farms, but more than 30 single 60kW to 1·5 MW turbines have been erected in the UK to power hospitals, factories and housing projects. Two wind turbines were proposed for the GMV site but only one will be built as the developers failed to win planning permission for one, a common potential stumbling block for this particular energy source, especially in the kind of urban, high-density locations where today's new homes are most likely to be built.

GMV also focused on cost. "Cost and payback is a big issue," says Richard Hodkinson, of GMV's innovation consultant Richard Hodkinson Consultancy. "There are much better things you can do, like having a more efficient boiler." The developer is however already achieving a 65% reduction in primary energy consumption, through the application of chp, and is reducing CO2 emission levels for each home from the average of 3·5 tonnes a year to around 1·1 tonnes. Originally, the developer planned to fuel its chp plants using biomass, but it has since rejected the idea. "We came up against three issues: space to store the fuel, cost and supply difficulties, and concern about the emissions being given off by the chp engines," says Hodkinson.

GMV does not believe that it is attracting buyers on the green benefits of their homes either and chp is being marketed as offering the convenience of a "boiler-free home". "You have to bring it down to something tangible," says Clive Cain, senior development manager with GMV.

Buyer resistance to unfamiliar technology is often quoted by housebuilders as another potential obstacle to renewable energy, and both Laing and GMV are educating their customers, Laing with seminars for homeowners explaining exactly what they have bought, and GMV with a technical data sheet on renewable energy that can be picked up by interested visitors to the sales centre.

But housing association the Peabody Trust has made a virtue of energy saving by christening its 82-unit housing scheme in Sutton, Surrey, the Beddington Zero Energy Development, or BedZed. The scheme combines homes for affordable rent, shared ownership and outright sale and all potential occupants have responded equally enthusiastically to the scheme's green features, including a chp plant fuelled by biomass. "It helps that the scheme is in Sutton which is known for being an environmentally-friendly borough. Its residents are quite environmentally aware," says a spokeswoman for the Peabody Trust.

Private housebuilders do however see scope to include photovoltaic panels and other environmental technology on the list of optional extras which early buyers can have added to their new homes at a supplementary cost. To this end housebuilder David Wilson Homes is trialling green technology in a research project with University of Nottingham. "As part of a standard package the majority of purchasers wouldn't value it," says Mike Stansfield, managing director of David Wilson Homes. "But there are still a significant proportion of people who would pay more for them."

In the housing market, consumers will lead the way. Until people buying houses start asking for sustainable features, housebuilders have no real incentive to add them – unless the penalties for not doing so are made harsher.

Two approaches to chp

As a rare large-scale private housing application of chp, Greenwich Millennium Village (GMV) is a testbed. “We’ve already learned some big lessons – like not to oversize the plant, and how to procure. We actually had it done as part of the usual building services design,” says innovation consultant Richard Hodkinson of Richard Hodkinson Consultancy. Services engineers on the project are WSP and Thorburn Colquhoun. The scheme is being equipped with a series of chp plants, which are being constructed alongside and among the homes, allowing the developer to phase its investment in plant. GMV owns the energy centres and has awarded Alstom an initial 30-month contract to manage the facilities. “After that our options are open – we could sell them, or the village’s management company could own them,” says Ross Hammond, project director with the consortium. The first energy centre is located in the basement of an apartment block and has an output of 80 kW, to serve 100 homes. A second larger 450 kW output energy centre is currently under construction to serve 450 homes. The developer will be sourcing its photovoltaic panels and wind turbine from supplier Proven Technology. Across London at Beddington Zero Energy Development, in Sutton, the Peabody Trust’s homes will have heating and hot water generated by a 110 kW chp plant fuelled by biomass. The biomass is waste timber, sourced from a local tree surgery and cut from local trees. The chp unit generates electricity and distributes hot water round the site via insulated pipes. These deliver heat to domestic hot water cylinders positioned centrally in each home so that they also serve as heat emitters. There are photovoltaics at BedZed too, as the scheme has a 109 kW installation from BP Solarex to charge the batteries of the scheme’s pool of 20 electric cars. The zero energy concept was developed by environmental consultant BioRegional and architect Bill Dunster. Ove Arup and Partners is services engineer on the project.