15 February 2018
By Rosa Shirm
From Grey to Green: Transforming the City with One Green Wall at a Time
Green Infrastructure in 2018
The recent launch of the government’s long-awaited 25 Year Environment Plan has been the hot topic of conversation amongst sustainability professionals, as the industry eagerly analyses the government’s plans to drive forward the agenda of a ‘cleaner and greener’ Britain. At KLH Sustainability, we are particularly interested in the government’s intention to enforce mandatory requirements on developers to integrate green infrastructure in the built environment. The plan seeks to integrate more stringent green considerations into building planning, and successfully captures the shift in sustainability goals by embedding an ‘environmental net gain’ principle.
At KLH Sustainability, we are strong advocates of integrating green infrastructure into our urban environments. The challenge we face in increasingly dense cities such as London, is the scarcity of open areas for the development of green space. The solution is, of course, to be innovative with the space we do have. Integrating green infrastructure in dense, inner-city space can be made possible by seeking opportunities on buildings’ facades, transforming the dull, urban grey into green walls.
More than attractive architectural statements of environmental consciousness, green walls have a role to play in improving our cities as the rate and intensity of urbanisation accelerates.
Green walls provide large surface areas for pollutant deposition and can result in local reduction in concentrations of particulate matter between 10-20%. Within street canyons (see figure 1), this can increase to a reduction of particulate matter by 60% and nitrogen dioxide by 40%. In addition to air quality, green walls are a key component of a city’s functional network of green spaces. Not only do they provide new habitats, but they also facilitate movement between habitats by contributing to networks of green corridors across vast urban space.
Street canyons: pollutants can become concentrated when trapped in streets lined by high-rise buildings.
The benefits of green walls are not limited to the environmental but also span across the social reaches of sustainability.
Green walls present an opportunity to use limited space to improve the quality of life for people in urban areas. The positive links made between the natural environment and an individual’s sense of wellbeing, stress reduction and mental regeneration are amongst the well-established restorative benefits of contact with nature. Studies also show that green facades can absorb sound energy that normally would be reflected by concrete glass and steel and can reduce sound levels from traffic by 15dB. This minimises the excessive noise that threatens the wellbeing of urban residents.
Green walls provide a healthy and functional way for cities to become more attractive, resilient and increase the quality of living for residents, whilst competing with issues of diminishing space in inner-urban environments.
On our East Wick and Sweetwater project, the team have sought to improve the residents’ quality of life and the local environmental conditions within the Queen Elizabeth Olympic Park by designing in green walls on the facades of the new developments, and the green roofs on our St James’ Market project form part of The Crown Estates “Wild West End” strategy to connect St James’s Park in the south to Regents Park in the north via a building-integrated green corridor.