Forwarded to you all from Cornelia Oberlander…
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
Read yet another article recently about the city of Vancouver being pro green roof and can’t help but be more frustrated and confused.
The time came when I was finally in the financial position to build my dream garage and really wanted a green roof. Helped my brother build one on his farm four years ago, it was simple and still looks great. Now I knew I’d have to go through city by-law politics so I did a bit more planning since I designed and am building this garage all by myself. Through BCIT I received very detailed info on the construction of a green roof and added this to my blueprints. Blueprints first went through an engineers approval and then a roof truss suppliers approval. At city hall during the lengthy approval process I was asked for permission to copy my roof details since they apparently had no guide line for green roofs. With pride I happily agreed but started to have my doubts when I received a lot of strange looks from city hall about my odd ball plan. Eventually I was asked for additional approval from an architect to explain ‘the interaction of the roof membrane and structure below.’ It would be waterproof was what I thought. Anyhow after many phone calls just trying to find an architect willing to work on a residential project I was quoted with an estimated $1700 minimum. So I went back to city hall crossed off my beloved green roof detail in front of them and said “I am just putting up a flat roof with a membrane and will just let the leaves and moss pile up on it”.
“That is fine” was there reply.
It is one of those moments you can laugh at when you look back at it. But my warning to others out there don’t waste your time on the green roof let mother nature worry about it.
Sincerely
Filip Hroch
Hi Filip. You were absolutely right to think a green roof will work. The trouble is that those that have been warming the same chair for 30 years in City hall have no idea, and are scared of anything they have no idea about. It is ridiculous, status -quo thinking like this that is holding this city and others back from what they can be.
Mayor Roberts talks green but he sure can’t back it up when something as simple as a green roof can’t get past the chair warming bureaucrats right under his nose.
Keep pushing! When and if I can ever afford to own a home in this city (being from here), I will try to get my green roof approved as well.