These two projects, with 400-500 units, involve an investment of around Rs.10 billion each.

'We have received proposals from the DLF group as well as the Siddha group for setting up clusters of such units at Rajarhat in Kolkata,' WBREDA director S.P. Gon Chaudhuri said.

'We have agreed in principle for the DLF proposal but are yet to weigh Siddha group's proposal,' he said.

The units would have solar panels on the terrace to generate power for residential use; excess power, if any, would be sold to the state grid.

'They proposed to build 400-500 houses spread across 70 acres. Apart from solar power, the projects would also have rainwater harvesting capabilities as well as equipment to convert waste into energy,' Gon Chaudhuri said.

These units would be built with green materials, which are made by consuming lesser amounts of energy in comparison to traditional building materials.

The two proposals come close on the heels of WBREDA's Rabi Rashmi Abasan project, India's first commercial solar housing scheme.