Biodiversity Net Gain for local authorities

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

What do local authorities need to do?

The Environment Act 2021 makes biodiversity net gain mandatory for all but small sites and some exemptions from 12 February 2024 and for small sites from 2 April 2024. Councils will need to be ready to meet the new legal requirements then.

BNG has been required through national planning policy in England and Wales for a number of years, and can be achieved on site, off site, or through a combination of on-site and off-site measures. You can find more information about this on our Biodiversity net gain now and in the future page.

There is a lot of preparation required to get ready for the new legal requirements, including planning decision-making and policy, and our BNG readiness checklist provides a high level overview of what local authorities need to think about in preparing for BNG across the board. It’s worth thinking beyond the legal essentials if you want to make BNG really deliver for nature and people in your area:

  • BNG is not just about planning. How you could join up across council services?
  • Have you declared a climate and ecological emergency? BNG is an action you can take in your plan to address these twin emergencies.
  • BNG links into place-making and infrastructure and you can collect evidence about:
    • what you want your borough’s natural environment to look like, and
    • how the natural environment can deliver for local people.
  • Local Nature Recovery Strategies (LNRS) are being produced at the county, unitary or combined authority level and there will be other opportunities associated with working with neighbouring authorities on BNG.
  • BNG will involve local communities, landowners and farmers, especially where delivery of BNG happens off the development site. 
  • BNG will need expertise and resourcing.

This article in LGA's first magazine highlights how enhancing biodiversity through the planning system creates a range of benefits for local communities.

How can local authorities plan for and deliver biodiversity net gain?

We've been talking to lots of local authorities about BNG and what they have been doing to implement BNG. We have developed webpages on The BNG Journey to provide further information and examples of what local authorities are already doing to plan for and deliver BNG and drafted a BNG readiness checklist to to help LPAs structure an approach to preparing for mandatory BNG. A recording of a session in July 2023 on BNG for Planners which PAS's Beccy Moberly contributed to with The Planner and Environment Bank is available on The Planner website. Defra have set out 10 actions local planning authorities can take to prepare for Biodiversity Net Gain (BNG).

Where you join the journey will depend on where you are as a local authority, what your priorities are and what you're already doing, and we hope these resources will help you decide on what approach you take to the journey. Feedback is welcomed, please email Beccy Moberly with your suggestions.

How is PAS helping local authorities get ready for biodiversity net gain?

PAS has been commissioned by Defra to work on a LPA Biodiversity Net Gain Capacity and Skills project. This is an ongoing project, which started March 2021. The overarching aim is to support LPAs in delivering mandatory BNG from 12 February 2024.

We are developing a training and support programme for the 330+ LPAs England-wide, including resources for policy planners, development management planners, and councillors.

We have run a number of events as part of this project and you can find more information about these on our Biodiversity Net Gain Events page.

We have produced a Biodiversity Net Gain essentials slide pack that local authority officers can use to provide an overview of biodiversity net gain to colleagues, members and senior managers with a recording of a run-through of this also available.

We have a practitioner network that any local authority officer interested in BNG can join. We host meetings every 6-8 weeks and have an online forum where members can post questions, discuss issues and share resources and information. If you wish to join this network, please fill out this Microsoft Form.

Feedback welcomed on this page and please do share your examples with us: [email protected].