HOUSING
LIVING WALLS LEAD URBAN UPRISING Incorporating biophilic design principles in landscape architecture is essential if our cities are to become more climate resilient. Here, Richard Sabin, Managing Director of Biotecture, looks at why that and other benefits make living walls the stand-out choice for overcladding projects.
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ver the last few years, the UK has faced a number of pressing urban challenges including poor air quality, loss of biodiversity and urban heat island effect. There is a growing understanding that living walls provide an effective way to help tackle these issues, particularly when space is at a premium. That brings us appropriately enough to the questions that we are commonly asked by architects and designers about adding living walls to existing buildings.
Can living walls be fitted as a rainscreen cladding system on an existing building? Yes, living wall systems are available that are designed and validated to ‘work’ as the rainscreen cladding element of buildings, whether fitted to a new or existing building. That makes a living wall system integral to the building design and in terms of value should be considered against other cladding systems rather than being seen as an additional cost. They comprise a supporting framework that is anchored back to the structure, along with CP board, waterproof membrane, ventilated cavity and vegetative panels.
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The total overall outward projection of a living wall from the structure can be as little as 80mm, which is again comparable with other rainscreen systems.
Do living walls impose weight loadings on existing facades? As with any rainscreen cladding system that is used to overclad an existing building, it is necessary to carry out a structural survey to verify that the structure can withstand additional loading. A structural survey will inform you of the most appropriate living wall system to use. Where the survey identifies that the facade is capable of accepting additional weight loading, it is possible to use a living wall product, such as BioPanel, which is similar to any rainscreen cladding system. If the existing masonry facade won’t accept additional weight loading, we guide specifiers as to the best way forward.
Where else can I specify living walls? Living wall systems can be used in a wide range of other locations, such as low-level walls, balconies, boundary walls, perimeter
fences for industrial plants, site hoardings, railings, roof gardens or terraces.
How do living walls help us tackle the climate emergency? Living walls help address the climate emergency in a number of ways. They help mitigate the heat island effect – proliferation of concrete, steel and tarmac in our cities absorb huge amounts of heat, creating their own microclimate. These elevated temperatures drive the need for energy-intensive air conditioning and cooling systems in what becomes a vicious circle. Living walls tackle this by creating building bio membranes, which involves choosing plant species that filter out sunlight, keeping the underlying surface of the building cooler and so minimising solar gain. That
