The competition was set up by the Living Steel organisation, which promotes the use of steel in new housing.
The practice, which also recently won the international Manubuild prefab housing competition ( Piercy Conner lands pan-European Manubuild contest), has picked up 50,000 euros (£34,500) in prize money, as well as the contract to develop these designs.
The Kolkata site was one of two locations in the competition, along with one in Warsaw, Poland, which was picked up by Dutch practice Architectenbureau Cepezed.
Piercy Conner's project aims for a simplicity of approach to keep costs and build times down. This has informed the development of the sun-screens, which are reminiscent of Indo-Islamic architecture. The simple fixing system used to construct them is quick to assemble.
Jury chair Glen Murcutt said he was 'struck by the simplicity and lightness of touch of the scheme'.