The plan was originally drafted by French environmental activists. They had wanted a stricter rule requiring all new buildings to be covered. The government had to convince them to limit it only to commercial buildings to make sure people still wished to invest on real estate.
Green rooftops will help to keep the buildings cool in summer. The solar panels can provide electricity for any other air conditioning needs.
This project is helping France to catch up with other European countries in the solar power race. The capitol has started to invest in many more green, alternative energy projects, such as the NewWind wind tree.