Plant-Covered Walls Can Combat Urban Heat and Help Biodiversity
Sourced from Phys.org
Plant-covered facades help cool urban areas and provide habitats for plants, birds, insects and other organisms. An international team of researchers has drawn this conclusion after systematically comparing green walls, bare walls, and natural cliffs.
The research was led by Utrecht University ecologist Katharina Hecht, and published in the journal Building and Environment.
"Green walls can be much more than just a decorative trend," says Hecht. Up until now, construction companies and authorities promoting green walls have lacked hard evidence for their claims. Hecht's study now sheds light on how much these lush, green walls boost biodiversity and under what conditions, in addition to reducing urban heat.
The research was a collaborative effort, bringing together researchers from Utrecht University, including microbiologist Han Wösten, the Resilient and Inclusive Cities Lab at Singapore's Nanyang Technological University, led by Perrine Hamel, and the Singapore-based company bioSEA, led by Anuj Jain. Together, they analyzed a total of 20 walls in Singapore's urban environments.
Cooler surface
Green walls were shown to significantly reduce air temperatures around buildings. Researchers found daytime cooling effects of up to 0.6—0.7 degrees Celsius between the front and back side of green walls.
"This might sound like a small difference," says Hecht. "But in the context of urban heat, even small reductions can lower energy costs, and make buildings more comfortable to life and work in." With more and more green walls being built, this cooling effect can contribute to mitigating the urban heat island phenomenon. "It also helps improve overall climate resilience in cities."
More biodiversity
Biodiversity benefits were also significant: green walls hosted over 100 animal species, including insects, spiders, and birds. These numbers far surpass the number of species typically found on non-vegetated walls, which are only a handful.
From the Living Architecture Monitor
