A look round the 'impossible' zero-carbon house
Professor Phil Jones from Cardiff University gives a tour of a zero carbon property near Bridgend.
Chancellor George Osborne scrapped a requirement for new homes to be zero carbon by 2016 because he said it would prove too expensive.
The house took just 16 weeks to construct and cost £1,000 per sq m - that is within the range for social housing of £800 to £1,000 per sq m, the designers said.
The property has insulated render on the outside and air heating systems that rely on the sun.