Project Description
The redeveloped former Oaks shopping centre in Acton, West London provides 178 new apartments and 42,000 sq. ft. of retail space. ABG worked with Osel Architecture, developers O’Shea and contractors Cawston Specialist Roofing to implement the blue roof attenuation system design for the project.
The Challenge
The redevelopment project required SuDS planning measures to minimise contribution to local flood risk and to meet the water authority’s site discharge limits. Underground stormwater storage tanks are problematic and expensive to construct in town and city centre locations such as this, with the excavation process creating additional site traffic that adds to carbon emissions and causes extra site safety management risks.
The Solution
ABG provided a design alternative to implement a total of 11 blueroofs areas to attenuate and control the discharge of stormwater across the various roof levels, including onto five separate podium decks. The blueroof attenuation volume was designed to accommodate a 1 in 100 year storm event, plus 30% allowance for climatic change and calculated to match the discharge consent limit defined for the site catchment area with NHBC approval.
The ABG blueroof system is used to provide temporary attenuation of stormwater, and to restrict the rate that water enters the wider drainage network. The ABG blueroof design means the stormwater attenuation requirements were met within the roof and podium build-ups, and therefore the need for expensive underground storage or other SuDS methods could be avoided.
The ABG blueroof system provided a carbon saving alternative for retrofit onto the Oaks redevelopment, with installation of attenuation at roof level estimated to have reduced carbon emissions by 59% compared to excavating basement stormwater tanks. In addition to the blueroofs, ABG also installed five biodiverse green roof areas that further improved the sustainability rating of the redevelopment.
The ABG Service
ABG provided a full technical solution from design to manufacture, supply and installation of the blue and biodiverse roof systems.
