Living walls installed on buildings can play a meaningful role in restoring biodiversity in cities, according to new research that highlights their value as habitats for a wide range of wildlife. The study shows that these vertical green structures provide refuge, food and nesting opportunities for animals in densely built urban environments where natural habitats are increasingly scarce.

The research examined living walls—structures fitted to the exterior of buildings and planted with flowers and vegetation—across three locations in and around the city of Plymouth. The sites represented a mix of urban settings, including the city centre and areas on the outskirts, allowing researchers to assess how wildlife responds to living walls in different urban contexts.

Over three separate survey periods, scientists recorded activity from a wide range of species, including pollinating insects, spiders, soil-dwelling invertebrates, birds and bats. The surveys documented hundreds of individual animals, demonstrating that living walls can support complex and varied ecosystems even in highly modified environments.

Among the most notable findings was the diversity of pollinators using the structures. The study recorded 12 different species of bees, hoverflies and other pollinating insects visiting the living walls. In addition, researchers identified 19 types of soil invertebrates and 12 species of spiders living within or around the structures, indicating that the walls support multiple levels of the urban food web.

Birdlife was also strongly represented. Across the three study locations, 32 bird species were observed interacting with the living walls. Importantly, three common urban bird species—house sparrows, blackbirds and robins—were found nesting directly within the structures, showing that living walls can provide safe breeding spaces in cities where traditional nesting sites are often limited.

The research found that the design of living walls plays a crucial role in determining their ecological value. Walls that used plants rooted in soil supported significantly more wildlife than those relying on artificial growing substrates. Plant selection also proved important, with species such as ivy, Mexican daisy and honeysuckle attracting the highest numbers of pollinators.

The findings were published in the academic journal Urban Science and suggest that well-designed, soil-based living wall systems can deliver substantial biodiversity benefits when combined with carefully chosen plant species. The study adds to growing evidence that green infrastructure can help mitigate the negative ecological impacts of urbanisation.

With global urban expansion accelerating, the researchers stress the importance of integrating biodiversity-friendly design into new and existing buildings. Current projections estimate that around 68% of the world’s population will live in urban areas by 2050, increasing pressure on wildlife habitats. Living walls are increasingly viewed as one way to support species that would otherwise struggle to survive in cities.

The project was carried out by scientists and students from the University of Plymouth, drawing on expertise from both environmental and biological sciences. A combination of visual surveys, invertebrate sampling and acoustic monitoring was used to assess animal activity at three living wall sites: the University’s Sustainability Hub, the Genesis Building on Union Street and the Sherford new town development.

Beyond biodiversity, the University of Plymouth has been examining other environmental benefits of living walls. One of the structures included in the study was installed at the Sustainability Hub in 2019 as part of the University’s long-term commitment to sustainable building practices. Ongoing monitoring has allowed researchers to evaluate its performance over time.

Previous research published by the University in 2021 found that retrofitting an existing building with a green or living wall can reduce heat loss through the structure by more than 30%, highlighting additional benefits for energy efficiency and climate resilience.

Together, the findings underline the potential for living walls to contribute to more sustainable and wildlife-friendly cities. As urban planners and policymakers look for ways to balance development with environmental protection, the study suggests that living walls could play an increasingly important role in supporting urban ecosystems while delivering wider environmental benefits.