See the October, 2008 Greenroofs.com Guest Feature Article by Frances Carroll here. Visit the West Midlands Fire Service website here. For more info on this project, please contact the landscape architect, Frances Carroll, of Moore Environment at: T 01675 466877; F 01675 466899; [email protected]; or visit http://www.moore-environment.co.uk/index.html. See the Moore Environment’s Technical Summary of the project here. Contact the client, Allan Parsonage, Project Manager, at: [email protected], 0121 380 6015; and Pete Wilson, Safeside Complex Manager, at: [email protected], 0121 380 6429.
The West Midlands Fire and Rescue Authority?s (WMFRA) new Regional Head-Quarters in Birmingham, completed in May 2008 appears to be a triumph for sustainable development. The new HQ development is located on a 4.34 acre site at Vauxhall Road, close to the centre and east of Millennium Point Birmingham. Built on a ?brown field site? formally a disused Cooperative dairy, it now houses over 7100 m2 of office space plus a dedicated educational facility. By incorporating sustainable construction practices the development met one of its key objectives; the achievement of an ?Excellent? BREEAM rating. These include a combined rainwater harvesting system, (supplying water to the toilets) and the construction of a new green/brown roof so called because the design evolved from an original proposal to include an ornamental ?green? roof and the introduction of a ?brown? roof once the client learnt such a roof was more likely to enhance bio-diversity.
The ?20,000 green/brown roof was designed by Moore Environment, a company of Landscape Architects and Environmental Designers and Assessors. The brief for the design was to provide an interesting outdoor educational space for visitors and staff and to replicate typical brown field land, which is considered to provide valuable and varied habitats for a wide range of fauna and flora. Within Birmingham such sites are known to have attracted the rare black redstart, a small robin-sized bird that has adapted to live at the heart of industrial and urban centres, where the terrain of typical brown field sites, with brick and concrete debris, resemble its natural mountainous habitat. The creation of habitats to attract this species was another key objective for the design of the roof.
To recreate suitable conditions the green/brown roof was installed utlising layers of material comprising mainly of demolition waste such as crushed brick and concrete, dusted with a sandy loam to create a substrate or growing medium. The substrate is laid in depths ranging from 75mm to 150 mm to add visual interest and for diversity of habitat for invertebrates and insects: particularly bees and butterflies. This dry material is alkaline due to the cement and mortar content but such a surface has proved to be a rich haven for native plants that thrive away from competition. Two dry meadow wildflower seed mixtures were applied at 2 grams per m2 with some areas deliberately left clear for colonisation by local species. Both mixes contain Sedum acre (Biting stonecrop), an extremely drought tolerant plant with high nectar reserves making it invaluable to insects.
Seed Mixture 1 was designed to be bio-diversity focused. It included:Agriomonia eupatoria (Agrimony), Agrostemma githago (Corn cockle), Anthyllis vulneraria (Kidney vetch), Centaurea cyanus (Cornflower), C. nigra ( Common knapweed), Daucus carota (wild carrot) and Silene vulgaris (Bladder campion).
Seed Mixture 2 included some slightly more ornamental species such as:Achillea millefolium (Yarrow), Campanula rotundifolia (Blue harebell) and Verbascum nigrun (Dark mullein).
In order to comply with fire regulations, an inert perimeter strip, min 500mm wide, was surfaced with washed pebble-mixture and left clear of seed and compost. Much of the research for the design of the roof was in collaboration with ecologists based at Birmingham University with a particular interest in the ecological benefits of the establishment of bio-diversity roofs. Other research has come via information found on the Living Roofs (www.livingroofs.org.uk) and the Black Redstart websites (www.blackredstart.org). Download the WMFRA Master Plan (PDF), shown below as a thumbnail, here.