As part of its overall strategy to become a carbon neutral city by 2025, Copenhagen has become the first Scandanavian city to adopt a policy that requires green roofs for all new buildings with roof slopes of less than 30 degrees. Copenhagen presently has 20,000 square meters (over 215,000 square feet) of flat roofs. It is hoped that as much as 5,000 square meters of new development each year will be covered with vegetation.
Vegetated roofs, or green roofs, provide several benefits for buildings and their surroundings. They can absorb as much as 80% of rainfall, helping to reduce stress on stormwater systems. They help reduce urban temperatures (the “heat island effect”). And, they protect roof membranes from the sun’s UV rays and the greatest temperature swings, such that roof membrane life is extended as much as double that of an unprotected membrane.
Thanks for the tip @mona_jensen!