On March 19, the French Parliament approved a law mandating that half of rooftops on new buildings in commercial zones be covered with either a green roof or solar panels. This new legislation is a compromise between France’s Socialist government and environmental interests, as it is limited in scope to commercial buildings and half, rather than their entire roof areas.

The law comes in advance of the United Nations’ climate summit, which will be hosted in Paris at the end of the year. Green roofs help to insulate buildings, reducing energy demand, and they decrease stormwater runoff, among other benefits.