green roofs not only for new buildings

Arup has shown that green roofs, which contribute to a better quality urban environment, can be viable as retrofits on existing office buildings. A green roof has been installed on an Arup office building in London to test the logistics of a retrofitted green roof and the use of recycled materials as an alternative to commercially available green roof products.

Green roofs generally help with water retention; reduce dust, smog and noise levels; add thermal insulation and provide a natural habitat for animals and plants. Arup's roof was designed for biodiversity and tailored to enhance local ecological value, particularly in the provision of a habitat attractive to black redstarts - a protected bird species present in the local area.

Illustrating another retrofit of a green roof on an office building, this one in Canary Wharf, here's more discussion of how biodiversity can be important in an urban area.