Green roofs are now required by law on all new buildings with roof slopes of less than 30 degrees in Copenhagen. It is hoped that as much as 5,000 square metres will be covered with new vegetation each year. The initiative is part of the city’s plan to become the world’s first totally carbon neutral city.

Toronto has also made green roofs compulsory but only on residential buildings that are at least six stories high.

A green roof on a building in Toronto
A green roof on a building in Toronto