Chandigarh may soon make solar rooftop plants mandatory for all houses and buildings occupying plots larger than 100 square yards in a first of its kind clean energy drive in the country.A notification to this effect is expected shortly, said Santosh Kumar, director of Chandigarh Renewable Energy Science and Technology Promotion Society (CREST), an arm of the union territory’s department of science and technology. CREST is in talks with Chandigarh administrator Kaptan Singh Solanki to get the urban planning department to issue a notification to this effect. “They are likely to issue it within this month,” said Kumar.According to the proposal, houses on plots of 100-500 square yards will have the option to install either a 1 kW solar plant or a 100-litre solar heating system. Larger houses will have no such choice. Those on plots of 500-1,000 square yards must set up solar rooftops of 1 kW, while those on 1,000-3,000 square yards will need 2 kW solar plant and those above 3,000 square yards must set up 3 kW solar plant.