The first commercially viable "zero carbon" house has been built by a Witney company.

The state-of-the-art property, know as Sigma, has been created by the Stewart Milne Group and fits in with the Government's aim that all new homes should be zero carbon within a decade.

With a timber frame shell made at the Witney plant, the building scores five stars on the new Code for Sustainable Homes - the highest rating currently possible for houses that can be built in large quantities.

Chairman and chief executive Stewart Milne said: "We see this as a major step in advancing tomorrow's homes to meet and hopefully exceed the future requirements of the Government and our customers."

The development was visited by Housing Minister Yvette Cooper at the Building Research Establishment exhibition at Watford yesterday, along with hundreds of visitors who queued up to get a look at the futuristic home.

Stewart Dalgarno, managing director of the Witney plant, said the development was part of a two-year research programme.

One of the hurdles is cost, with each plot currently costing £45,000 more to equip than a conventional home, but Mr Dalgarno said the possibility of cutting up to £1,000 a year in energy costs and being exempt from Stamp Duty would be attractive to many buyers.

The house is designed to be located in urban or suburban areas. It has an open-plan layout, and can have three or four bedrooms.

The ground floor can be separated from the upper floors to create a self-contained apartment or home office.

Features include solar panels for hot water and to generate electricity; roof-mounted turbines to generate power; and a 'grey water' recycling system, where washing water is stored to be used again to flush the toilets.

There are plans to make the new homes completely zero carbon, by linking them to a green source of power such as a large wind turbine.