Copenhagen and its green roof ambitions
Copenhagen is the first city in Scandinavia to have a manditory green roof policy. The new policy makes vegetation and soil a mandatory obligation in planning. The policy covers all roofs with less than a 300 pitch and also covers refurbishment of older roofs. However such roofs will get some public financial. The green roof policy is part of a wider ambition the City has to be carbon neutral:
’Copenhagen has set itself the ambitious target of becoming the world’s first carbon neutral capital by 2025. To meet this ambitious goal we need ambitious measures. Therefore we have now decided to ensure the City adapst to extreme weather conditions by making new requirements for getting grass on top of as many buildings as possible, ’ - Mayor of Technical and Environmental Administration, Bo Asmus Kjeldgaard.
The City of Copenhagen has set out four requirements for green roofs. Buildings with green roofs should be able to meet at least two of the following effects:
- Absorb 50-80% of the precipitation that falls on the roof.
- Provide a cooling and insulating effect of the building and reduce reflection.
- Help make the city greener, reducing the urban heat island effect, counteracting the increased temperatures in the city.
- Contribute to a visual and aesthetic architectural variation that has a positive effect on the quality of life.
- Double the roof life of the roofing membrane by protecting it against UV rays etc
Today about 20,0000 m2 of the roofs in Copenhagen are flat and at least 30 buildings have green roofs. It is envisioned that new development should add 5000 m2 per year – though this is only aspirational as i twill depend on the development cycle and economic factors
This is a summary taken from the press release by the City of Copenhagen on 17th May 2010