What is biodiversity net gain?

Biodiversity net gain is important because:

• the natural environment provides benefits to us all and is essential for the processes that support life on this planet
• it delivers measurable improvements for biodiversity by enhancing or creating new habitats in association with development.

Read Natural England's biodiversity net gain brochure (opens in new tab)

Biodiversity net gain is calculated using the biodiversity metric, produced by the Government, which is used to measure the biodiversity value of habitats on a site in biodiversity units.

Following the identification of habitats and their condition, the metric uses the biodiversity value of habitats found on a site before development, alongside the proposed habitats after development, to determine if there is a loss or gain in biodiversity.

For mandatory biodiversity net gain, developers must use the statutory biodiversity metric to calculate a minimum 10% biodiversity net gain from the pre-development biodiversity value of their development site.

• Read the Government's metric tools and guides (opens in new tab)

Achieving 10% biodiversity net gain means fully compensating for losses of habitat on a development site, and then going further so that, overall, there is a gain in biodiversity units of at least 10% as a result of the development process.

• Calculate biodiversity value with the statutory biodiversity metric (opens in new tab)

Habitat banks can be used by developers to achieve their mandatory minimum 10% biodiversity net gain.

• Read more on habitat banks

Under the Environment Act 2021 and supporting Statutory Instruments, biodiversity net gain is mandatory for most development.

Eligible developments must meet the mandatory requirement of a minimum 10% biodiversity net gain over the pre-development biodiversity value of the site. This can be achieved either on-site, off-site or with a combination of both.

• Find out more about BNG in planning applications