Work has been completed on the installation of a climate and water resilient research roof in the heart of Manchester.
The city centre workspace, Bloc, that has been transformed by Bruntwood Works as part of its £50m Pioneer redevelopment programme – the blue-green roof from Polypipe Civils & Green Urbanisation will help to develop a greater understanding of how new construction and data technologies can help cities and urban developments to mitigate the impact of climate change and population growth, while enhancing biodiversity.
Over the next two years, the ‘smart’ blue-green roof, designed by environment management consultants EPG, part of the STRI Group, will allow United Utilities – which co-funded the development at Bloc – to assess how storing and re-using rainwater at roof level can reduce the volume of surface run-off entering its sewer network. As a result, it will help to lower the flood risk associated with the prolonged high-intensity storm events that are becoming increasingly frequent as the climate changes.
Unlike conventional green roofs, which use a drainage layer to simply remove rainwater, the 525 sq m blue-green structure retrofitted to Bloc’s flat roof stores rainwater beneath the planted surface where it lands. Advanced passive irrigation components within the attenuation layer draw water up through the structure to the underside of the green roof substrate to support surface planting.
The technology protects green areas during periods of drought, reduces potable water demand during hot weather and enhances biodiversity by maintaining flora in optimum growing conditions. In the case of Bloc, planting has been specially selected by partners of the project, STRI, from local varieties to help attract pollinators and a particularly rare butterfly, the Manchester Argus.
This Net Zero re-use of water to sustain surface planting is a new approach to water management known as green urbanisation and represents the next generation of sustainable drainage systems (SuDS).
Nicholas Wright, Specification Business Development Director at Polypipe Civils & Green Urbanisation, said: “The two-year roof research programme at Bloc will demonstrate the full creative and multifunctional potential of green urbanisation, which represents the next generation of sustainable drainage systems.
“By introducing integrated natural habitats across the urban landscape, we create healthier, more resilient communities that are highly carbon and energy efficient.”
Sophie Tucker, United Utilities’ Area Engineering Manager, said: “As a company we continue to explore innovative ways on how things can be done differently, as we look at alternative methods to increase resilience in our sewer systems, away from simply building underground. As such, we’re heavily invested in learning more about urban assets that can deliver surface water separation and sustainable solutions which can make our regions more resilient to the long-term impact of climate change.”
Polypipe Civils & Green Urbanisation’s Permavoid solution has been used at Bloc to create the blue-green roof structure. The shallow sub-base attenuation system, which is made from 100% recycled polymer, manages rainfall at source. This collected surface water is then either retained for re-use or gradually released to help prevent flooding ahead of periods of extreme weather.
Learn more about Permavoid, green urbanisation and the new technologies supporting sustainable urban green asset creation here.
