Page updated 8 February 2024. This is the front page of a set of resources PAS is developing to support local authorities with the introduction of mandatory biodiversity net gain. It provides an overview of biodiversity net gain and why it is important. Links to further content are at the bottom of the page. PAS has a BNG practitioner network for local authority officers. A link to a form to join the network is available further down this page.
Overview of PAS BNG resources
What is biodiversity net gain?
Biodiversity net gain (BNG) is an approach to development, and/or land management, that aims to leave the natural environment in a measurably better state than it was beforehand.
The word ‘biodiversity’ comes from the term ‘biological diversity’. It refers to the variety of all living organisms, including animals, insects, plants, bacteria and fungi. More information on biodiversity and its importance can be found on the Royal Society's website and the LGA has an e-learning module for officers & councillors on biodiversity. A habitat is the area and resources used by a living organism or assemblage of animals and plants.
Biodiversity net gain delivers measurable improvements for biodiversity by creating or enhancing habitats in association with development. Biodiversity net gain can be achieved on-site, off-site or through a combination of on-site and off-site measures.
For a simple overview, view Natural England's Introduction to Biodiversity Net Gain on YouTube.
Natural England have also produced a Biodiversity Net Gain brochure, which provides an overview of BNG and its benefits.
The British Standards Institute have produced the Little Book of Biodiversity Net Gain. You can also take a look at a recording and slides from the Natural England BNG update we hosted in April 2023.
Under the Environment Act 2021, all planning permissions granted in England (with a few exemptions) except for small sites will have to deliver at least 10% biodiversity net gain from 12 February 2024. BNG will be required for small sites from 2 April 2024. BNG will be measured using Defra’s biodiversity metric and all off-site and significant on-site habitats will need to be secured for at least 30 years. This sits alongside:
- a strengthened legal duty for public bodies to conserve and enhance biodiversity,
- new biodiversity reporting requirements for local authorities, and
- mandatory spatial strategies for nature: Local Nature Recovery Strategies or ‘LNRS’.
Further information about mandatory BNG and the Environment Act is available on our Biodiversity net gain now and in the future page.
Why is biodiversity net gain important?
The most recent State of Nature report, published in 2023, found that there has been a 19% decline in the average abundance of wildlife species in the UK since the 1970s. This is despite legislation and policy to protect biodiversity and wildlife.
Although certain sites and species are protected, there are limited mechanisms to value, maintain, enhance and create wildlife habitats beyond protected sites. As a result, most habitats continue to be lost to development, reducing nature's ability to connect and thrive.
BNG is additional to existing habitat and species protections. BNG aims to create new habitat as well as enhance existing habitats.
Nature is important in its own right, but it is also is essential for the processes that support all life on Earth, including humans. The natural environment provides benefits to us all through 'ecosystem services'.
For local authorities, BNG links to a range of agendas including:
- addressing the climate emergency
- place-making
- green infrastructure
- access to greenspace and nature
- mental and physical health and wellbeing
- flood resilience
- improving air quality