Eco-towns, intended to tackle the twin problems of housing shortages and climate change, have to be carbon zero as a whole, be an "exemplar" in one area of environmental development and have at least 30% affordable housing.

BBC: Assessment over eco-town project

"We developed these carbon zero homes from the design and development stage through to people living in them, " said Professor Mark Gillott, of the University's School of Architecture and Built Environment.

BBC: Green's Spring conference targets the banks and Labour