The Garden Guide

Sustainable roof design

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Sustainable cities , Sustainable gardens, Sustainable landscape architecture, Green building, Hundertwasser, Green roof planning, Solar panels, Landscaped Architecture, Walls and roofs, Roof garden,

From a lanship viewpoint, the roof is the most important aspect of a building. It receives the most sun and the most water and can provide the best habitat. We therefore congratulate the Jane Goodall Institute and Xchanging for sponsoring a Chelsea 2006 show garden to show what can be done. The roof garden was designed by Jennifer Hirsch, an American horticulturalist with a Kew diploma.

Photovoltaic (pv) solar panels flank two sides of the roof garden.The 24 palens can generate 720 kWh of electricity, equivalent to 22% of the annual usage of a family of 4, and saving 310 kg of carbon emission, had the power been obtained from fossil fuel. Rainwater is collected in stainless steel tanks which double as garden seats. With a vegetated roof:

  • half the runoff is retained on the roof - saving our rivers from being converted into concrete ditches with flood relief channels
  • summer temperatures below the roof are lowered by 20-30%

As Tom Turner wrote, the question all environmental assessors should ask is 'Will the roofs of new buildings be vegetated? If not, why not?' [Landscape planning and environmental impact design] (UCL Press, 1998, p 399)

The Jane Goodall 'Up on the Roof' sustainable roof garden at Chelsea 2006

A pv solar panel with roof decking and plants

Photovoltaic panels can be designed to fit with, and resemble, roofing tiles