Habitats, ecology and bio-diversity
Biodiversity net gain
Biodiversity net gain aims to leave the natural environment in a measurably better state after development or land management work.
Biodiversity net gain requirements
Biodiversity net gain (BNG) means improving biodiversity through development or land management. Biodiversity means the variety of plants, animals, and other living things.
The Environment Act 2021 requires qualifying developments to deliver at least 10% biodiversity net gain. This became mandatory on 12 February 2024.
We may not be able to approve a qualifying development if it does not demonstrate at least 10% biodiversity net gain.
The statutory framework includes a 'biodiversity gain condition'. Subject to some exceptions, this condition applies automatically when we grant planning permission.
You must meet the biodiversity gain condition before starting development. After receiving planning permission, you must submit a Biodiversity Gain Plan and get our approval before work begins.
You must also provide evidence to support some of the decisions in your plan.
The National Planning Policy Framework identifies improving biodiversity as part of sustainable development. It refers directly to providing net gains for biodiversity.
Policy EN4 of the adopted Swindon Local Plan covers biodiversity and geodiversity. It requires development to avoid negative impacts and, where applicable, provide biodiversity net gain.
Applications covered by the requirements
Statutory biodiversity net gain applies to all planning applications unless an exemption applies.
Check the biodiversity net gain exemptions.
Information you must submit with your application
You must provide enough information for us to assess how your application will meet the biodiversity net gain requirements.
Your application must include:
- a statement confirming whether you believe the biodiversity gain condition would apply if we grant planning permission
- the biodiversity value of the on-site habitat before development
- your completed biodiversity metric calculation, including the metric's publication date and version
- the proposed earlier assessment date and your reasons for using it, if you are not using the application date
- a statement confirming whether activities have reduced the site's biodiversity value before the application
- the date immediately before any unauthorised degradation started, if this happened between 30 January 2020 and the application date
- a description of any irreplaceable habitat on the site at the application date, or an agreed earlier date
- a scaled plan showing north, the site's existing habitat, and any irreplaceable habitat
Please note, we may refuse to validate your application if you do not provide this information.
Calculate the site's biodiversity value
You must assess the site before development to calculate its biodiversity value.
Submit the relevant biodiversity metric with your application. This must be either the Statutory Biodiversity Metric or the Small Sites Biodiversity Metric.
You must:
- submit the metric as an unlocked Excel file
- show how the development will deliver at least 10% biodiversity net gain
- prioritise providing the biodiversity gain on the development site
Use the statutory biodiversity metric tools and guidance.
Providing biodiversity gain off-site
You should provide biodiversity gain on the development site wherever possible.
If you propose off-site biodiversity gain, you can:
- buy biodiversity units from a registered site
- create and register a biodiversity gain site on land you own
- buy statutory biodiversity credits
You must provide a statement explaining how you have followed the biodiversity gain hierarchy.
If we accept off-site biodiversity gain, you must provide evidence that you have bought the units or credits from a registered source. You must also show that they are allocated to your development.
Submit a Biodiversity Gain Plan
If we grant planning permission, you must prepare and submit a Biodiversity Gain Plan before starting the development.
The plan must set out your final approach to biodiversity net gain. It must include all relevant information, habitat management plans, and arrangements for managing and maintaining the gains.
Read the guidance and use the template to submit a Biodiversity Gain Plan.