Save-the-planet overtures and tighter building regulations may be convincing more householders to think green, but it's spiralling utility bills which are causing them to act.
High fuel costs are a compelling reason to study your home's energy-efficiency and make improvements that could save thousands of pounds a year as well as cutting damaging carbon emissions.
The Government's proposed Green Deal offering grants of up to £6,500 will be an incentive for those who lack confidence or money to invest in energy upgrades to existing homes.
Others may be tempted by the lower running costs of a new house, which on average are six times more energy efficient than older ones.
The Code for Sustainable Homes
Since April 2008, all new-builds have been covered by the Code for Sustainable Homes, a green standard which works on a points system and grades properties on a scale of one to six using criteria such as water-saving and onsite "micro generation" from, say, solar technology or wind turbines. Level six is the most "sustainable" rating and requires all energy to come from zero-carbon sources. Such homes are highly insulated and almost airtight.
From 2016 every new home will have to be level six, a standard developers so far have been slow to embrace despite a raft of building regulations which are starting to bite. Experts estimate fewer than 20 level-six projects have been completed in the UK and most are one-off houses. Even the Department for Energy and Climate Change cannot give a precise figure.
Meeting the zero-carbon target
Energy used to heat, light and run our homes accounts for 27 per cent (40 million tonnes) of C02 emissions in the UK. But only a 50 per cent reduction in carbon emissions is possible using all the key technology now available, according to Berkeley Homes.
Green architect Bill Dunster, designer of the BedZed/Peabody housing scheme in Sutton, the UK's first zero-carbon development, is working with Essex developer Grover Property on a level-six scheme of 88 super-insulated prefabricated homes.
Called Eco Grove, it includes a community farm where food will be grown for local residents. Homes are set to go on sale later this year. Another project, BohoGreen - which is for 67 apartments in Hove - is in the pipeline. Call Zedfactory on 020 8404 1380.
Meeting the zero-carbon target is estimated to add about £35,000 to the cost of a home. Developers doubt buyers are prepared to pay more. If builders are unable to pass on extra costs, land values are likely to fall.
No need for heat
Currently, the most environmentally advanced homes in Europe are those built to the German Passivhaus construction standard. These do away with the need for a conventional heating system by being airtight, using lots of insulation and a heat recovery system that transfers heat from air being expelled from the building to cooler, incoming air.
Four such homes are available to buy at Aubert Park, Highbury (right). Triple-glazed, south-facing and insulated, they look fabulous and are so energy efficient that no heating is required. Built on a former factory site amid Victorian terraces, the 3,000 sq ft family homes have the restrained modernist look of the best Scandinavian or Continental architecture. The timber frame structure has a thermal skin wrapped in crisp white render, iroko and zinc cladding.
Such homes need not cost a fortune to build. "About £1.50 a sq ft, which is less than in the housing association sector," says Pieter Brons-Harper, the developer. Of course, there is the cost of land plus professional fees and a profit margin, meaning buyers are being asked to pay £2.2 million for each one of the houses. Call estate agent New London on 0845 643 1500.
The website greenmoves.co.uk features green homes on sale, while you can visit WWF's campaign at: wwf.org.uk/sustainablehomes. For details of how older properties can be made energy efficient (with the Energy Savings Trust); visit est.org.uk.