As director of Livingroofs. org I have always had concerns with the green roofs at BedZed.
Green roofs do work. This is usually reliant on the correct FLL (German)-accredited system being chosen and installed properly by a competent contractor. Livingroofs. org only promotes green-roof companies that are accredited. All too often contractors or specifiers choose a non-accredited greenroof system. Good green-roof systems can be seen throughout London, especially at Canary Wharf, where the first green roof was installed in 2000. There have been no major problems with the sedum blanket systems at Canary Wharf, which now has the second largest area of green roofs in the UK.
It would be detrimental to the uptake of green roofs in the UK, and their significant contribution to sustainability within the built environment, if one green roof on a high-profile building were to give the industry and the technology a bad name, through what appears to be poor design and installation. The fact that the sedum blankets adopt part of the curving roof profile hasn't helped; these systems aren't designed as such.
However, the experience at BedZed does highlight a serious issue. There is a lack of knowledge and understanding of green-roof systems in the UK, particularly for prospective clients wishing to improve the environmental performance of their buildings. Part of Livingroofs. org's mission statement is to provide independent advice and raise the profile and knowledge of green roofs in the UK. I am aware that Zedfactory is promoting further green roofs on its new schemes.
I trust that the use of an unaccredited system poorly installed will not turn it and other architects and regeneration professionals away from installing green roofs. We have made significant advances in the understanding of green-roof systems - including sedum blankets - and their benefits, since BedZed was constructed.
There are more than 100,000m 2 of green roofs in London. As far as we are aware, they are a success and we, along with key industry stakeholders, will continue to promote them and their appropriate installation.
Dusty Gedge, Livingroofs. org, London