20.05.2011
Recently, there have been discussions within municipalities and construction seminars about green roofs in Finland. Green roofs are still very rare in Finland.
A green roof is a roof of a building that is covered by vegetation. Green roofs reduce flooding and persistent heat. The vegetation on roofs binds water that would normally run to the streets and sewers. Vegetation on the roof evaporates water which reduces the temperature and increases air moisture in the area. Additionally, green roofs reduce noise and protect the roof structure of buildings.
For example in German, about 10 percent of roofs are covered by vegetation. In Canada and Switzerland green roofs have become mandatory in certain cities. In Toronto, new buildings must have more than half of the roof area covered by vegetation. In Basel, all the new level roofs must be covered by vegetation.
There is on-going research at which type of green roofs would be suitable for Finnish buildings. Researchers wish that green roofs would not come from other continents and in bulk form, because this would lead to foreign plants and vegetation spreading to Finland, which could harm the nature. (Source: Helsingin Sanomat, 3.5.2011)