The Government has introduced changes to Biodiversity Net Gain (BNG) requirements which are intended to reduce the burden on smaller developments. The reforms, which came into force today (6 August 2026), recognise that the previous requirements could be complex and costly for smaller schemes. For many developers and landowners, the changes should make the planning process simpler, more proportionate and and less costly.
What’s changed?
The new measures include:
- An area-based exemption from mandatory BNG for smaller sites up to 0.2 hectares (more limited than earlier proposals, which suggested an exemption for all sites under one hectare). The justification for this is to ease the burden on SME developers and streamline the planning process
- A separate exemption for qualifying temporary developments of five years or less
- Measures intended to make it easier, quicker, and cheaper to deliver BNG offsite
- The previous exemption for self- and custom-build development has been removed
These changes apply to new planning applications submitted from 6 August 2026. Applications submitted before this date will generally continue to be assessed under the previous BNG requirements.
What does this mean for developers?
For many small developments, the changes will help remove one of the more significant planning hurdles by reducing the cost and complexity of demonstrating Biodiversity Net Gain. This should help some projects progress through the planning process more quickly.
However, the exemptions are not universal. Whether a proposal qualifies will depend on the specific characteristics of the site and the development being proposed, and many schemes will still need to demonstrate compliance with Biodiversity Net Gain requirements. Developers should therefore avoid assuming that all small sites are automatically exempt. Confirming whether a proposal qualifies at an early stage can help prevent delays later in the planning process.
Understanding how the new rules apply at an early stage can also help ensure planning applications are supported by the right environmental information from the outset.
What’s next?
The consultation for a residential brownfield exemption for BNG closed in June, so further legislative changes covering developments of this type are expected later this year. Until then, the existing rules still apply.
If you’re considering the development of a small site and would like advice on how the latest BNG changes affect your project, our planning consultants will be pleased to help.