New law requires green rooftops in France

More rooftops in France will soon go green. Under a law just passed by the French Parliament, new buildings in commercial zones must partially cover their roofs with plants or solar panels.

Although French environmental groups had lobbied for a more stringent rule that would require green roofs to cover the entire surface of all new buildings, the government has agreed to give developers the option of installing solar panels to generate electricity instead, reports The Guardian.

The new law “is a very positive step forward and a concrete lever for greener and smarter cities,” said James Watson, CEO of the European Photovoltaic Industry Association. “There are so many unused rooftops in our cities today and solar photovoltaics are the perfect solution to make the best out of them as they can be seamlessly integrated in an urban setting.”

James added that rooftops, large or small, represent 70 per cent of the installed solar capacity in France. During summer, green rooftops help keep buildings cool, while photovoltaic cells provide electricity for the remaining air-conditioning needs. The new regulation is expected to help France catch up with the fast solar adoption pace of other European countries, as well as jump on the green roofs bandwagon already popular in countries like Australia, Germany and Canada. 

Not only will the incorporation of green roofs in buildings change a city’s skyline, it could also work to lower urban air temperature and ameliorate urban heat island effects in France, which occur when generated heat is absorbed by the buildings, pavements and vehicles in cities.

Rooftop gardens also lessen energy demands and attendant CO2 emissions in a variety of ways – they can help improve a building’s insulation, reduce cooling and some winter heating costs, as well as lower the electromagnetic radiation from other buildings.