Enhancing Urban Development
Sourced from Architecture Today
In early 2024, the UK government introduced biodiversity net gain (BNG) legislation to address the ongoing decline in biodiversity caused by urbanisation, infrastructure development, and other human activities. This new, mandatory planning condition, obligates developers to ensure that their projects result in a measurable net increase in biodiversity. By doing so, the legislation aims to mitigate the adverse environmental impacts of development, ensuring that the natural habitats and ecosystems are not only protected, but also enhanced. The introduction of BNG is consistent with global efforts to stop biodiversity loss and safeguard the natural world for future generations.
How to measure biodiversity
A standard biodiversity metric is used to assess the number of units a habitat contains before development, it can then be used to estimate the units needed to replace any habitat loss and achieve a 10 per cent BNG. The value of biodiversity is measured in standardised units assigned based on various habitat factors, including type, size, quality, and location. After development, the assessment is repeated to verify the BNG enhancements.
The landowner is legally obligated to create or enhance the habitat and manage it for a minimum of 30 years to achieve the target condition. Therefore, designers must ensure that the new development meets the required biodiversity units, while committing to long-term monitoring and maintenance of the created or enhanced habitats.
Ways to achieve biodiversity net gain
Developers can achieve BNG in three ways: by creating biodiversity on site, or if that isn’t fully possible, through a combination of on-site and off-site measures. However, as a last resort, if the developer cannot attain BNG through these means, they must purchase statutory biodiversity credits from the government.
Green roof solutions that support biodiversity net gain
Green roofs are considered a valuable feature for BNG because they can offer habitat for a range of plant and animal species, while also improving air quality and reducing stormwater runoff.
The biodiversity metric 4.0 will value a green roof, assessing it on criteria such as the diversity and abundance of plant species, the presence of nesting opportunities for birds and insects, and the ability to support pollinators.
From the Living Architecture Monitor
