In 2024 the UK government introduced Biodiversity Net Gain (BNG) legislation to address the ongoing decline in biodiversity due to urbanisation, infrastructure development, and other human activities. The new compulsory planning condition requires developers to achieve a net gain in biodiversity through their projects to mitigate the negative impacts of development on the environment. This aligns with international efforts to halt biodiversity loss and preserve the natural world for future generations.
Measuring biodiversity
Biodiversity value is measured in standardised units. A site proposed for development will be evaluated using biodiversity metric 4.0, receiving units for the various habitats weighted by elements including type, size, quality and location. This process is then repeated after development to confirm the BNG enhancement.
Designers must ensure a new development will achieve the required units and commit to long-term monitoring and maintenance.
Solutions to support on-site BNG
Green roofs are considered a valuable feature for biodiversity net gain as they can provide habitat for a variety of plant and animal species. These living roofs provide an additional barrier against heat gain and heat loss, as well as creating a more energy-efficient building. A green roof can create a biodiverse habitat for the local wildlife and contribute to the reduction of the urban heat island effect where localised temperatures rise because of solar heat gain reflected or ‘stored’ within the hard construction materials. Green roofs also improve air quality and help to manage stormwater run-off to reduce flooding. On an educational level, when these vegetated or recreational spaces are installed on school buildings, they have proved to be valuable learning tools for students.
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.
After introducing green roof technology to the UK and Ireland more than 30 years ago, Bauder is now setting the standard by supporting designers and helping them understand the impact of specifying green roof systems by assessing their BNG value.
Each green roof project is unique in its requirements. If you would like to learn more about Bauder’s green roof solutions, contact Bauder here or call 01473 25767.
