In Peckham, south London, the London Wildlife Trust has built a visitors' centre made of timber, which consumed only a quarter of the energy that using brick would have involved. It has a 'living' roof of grass and wildflowers.
In Streatham, south London, J Sainsbury has designed a superstore around several listed buildings, including a 19th-century silk-mill. A leak- detection system prevents the escape of chlorofluorocarbons.
In Pembroke, Peter Holden Architects has converted a derelict quayside building into an office,using the stonework and many of the slates from the original building.
At Grove Road Primary School in Hounslow, west London, a central glazed courtyard cuts out the noise from jets passing overhead. Materials were recycled from the previous demolished building.
The award will be presented in London on 6 May.