The properties, which all lie just off the A45 by Sixfields, boast a 'sustainable urban drainage system' which offers an alternative to traditional drains.

Instead of using sewers for rainwater, the development has specially designed reed-bed ditches which create habitats for wildlife, as well as reducing the risk of flooding in heavy rains.

The green development has been made possible thanks to the persistence of English Partnerships, which owns the Upton site.

Tom Hustler, regional communications manager for the regeneration agency, said it had demanded tougher environmental standards than the standard planning regulations.

He said: "There is a demand for housing in Northampton and long-term what we are trying to do is produce places people what to live in, which have higher green standards than the usual building regulations demand.

"We have also made a point of hiring several different developers so there is a mixture of homes and designs."

One of the developments on the site, NU@D2, has been designed by housing company Barratts.

The flats and houses have photovoltaic panels which feed directly into the homes' hot water systems and extra-thick insulation. Prices start at £170,000 for a two-bedroom flat.

Karen Heath, sales manager at the site, said: "Some of the buildings have what we are calling a cedar roof. It is a green roof and will be made up of a material with plants growing from it.

"This means it will absorb water when it rains heavily and then release it slowly, rather than having it all rush down in heavy rain."