Shaw?s Cottage is a two-storey timber framed private house in the London Borough of Lewisham, built in 1993 using the Segal method. The roof was designed by EcoSchemes Ltd in consultation with the owner and architect John Broome. Reasons for the green roof included increased biodiversity and footprint replacement.
The Build Up of the Roof:Single ply butyl membrane covered by protective fleece. 60mm of rubble and subsoil covered by turf and on the pitch, gravel. On the steeper slopes a timber framework was constructed on top of the fleece to stabilize the substrate and a biodegradable jute covering mat used to prevent erosion during establishment. Gravel filled gutters connected to downpipes.Details of Green Roof Element:Designed to provide a variety of substrates and aspects, with areas of gravel/soil on flat areas, and chalk rubble/garden soil on pitched sections. The top section of the Shaw’s Cottage roof is 4 degrees and the steepest section on the Shaw’s Cottage roof is 23 degrees. The lower roofs are flat. The roof was partly turfed with lawn grass from the site and partly left to colonise naturally.By 2001 the vegetation of the different areas had become similar, despite the differing soil chemistry and aspects. Turfed areas were found to support a dense tussocky grassland sward comprising species such as Agrostis stolonifera, Dactylis glomerata and Phleum bertolonii, with herbs including Cerastium fontanum, Trifolium repens, Plantago lanceolata, Rumex obtusifolius, Malva sylvestris and, in disturbed areas, Medicago lupulina and Euphorbia peplus. Sedum had colonised the gravel.