Bio Diversity Net Gain
July 21, 20260

The Government has announced a significant change to England’s Biodiversity Net Gain (BNG) regime that will be welcomed by many homeowners, small developers and planning professionals. From 6 August 2026, most developments on sites of 0.2 hectares or smaller will be exempt from the mandatory requirement to deliver Biodiversity Net Gain, provided the development does not impact priority habitat.  Householder planning applications are currently exempt, but this now also includes Full Planning applications of the small-scale.

What is Biodiversity Net Gain?

Biodiversity Net Gain was introduced to ensure that development leaves the natural environment in a measurably better state than before. Most planning applications have been required to demonstrate at least a 10% increase in biodiversity value, using the statutory biodiversity metric.

What’s Changing?

Under the new regulations, developments with a red-line planning boundary of 0.2 hectares (2,000m²) or less will generally no longer need to comply with mandatory BNG.

However, there is one important exception.

If the development affects onsite priority habitat, the exemption does not apply, and BNG requirements will still need to be satisfied.

Not Every Small Site Will Be Exempt

Although the change simplifies matters, developers should not assume every small project automatically avoids ecological assessment.

Applicants will still need to demonstrate that the exemption applies, particularly where there is potential for:

  • Priority habitat.
  • Protected species.
  • Ancient woodland.
  • Trees protected by planning policy.
  • Other ecological constraints.

Local planning authorities may still request ecological information where required by planning policy or wildlife legislation, even if mandatory BNG itself does not apply.

What this means to current planning applications.

This only applies to applications made on or after 6th August 2026. As a result, any current application will need to be withdrawn and resubmitted to include the exemption.

For these existing applications, there is no refund for a withdrawal, and a new fee would be needed with the resubmission.

 

Summary

The new BNG exemption is a pragmatic adjustment that recognises the disproportionate impact mandatory biodiversity calculations can have on very small developments. For many homeowners and developers, it should make the planning process quicker, simpler and less expensive.

That said, biodiversity remains an important planning consideration. Even where mandatory BNG no longer applies, ecological constraints and local planning policies continue to play a key role in securing planning permission. At CK Architectural, we try to use the above to ensure that the projects both benefit our clients and achieve their goals whilst also remembering the importance of ecology.