Nature on a housing estate. Credit: Defra/Beth Carnell.
We are pleased to announce that yesterday we published and laid before parliament regulations which set in motion changes to Biodiversity Net Gain (BNG) for projects requiring planning permission under the Town and Country Planning Act.
These are the first batch of changes resulting from our BNG consultation last year, which we announced in our government response published in April 2026, and covered in our recent BNG blog post.
We can now confirm that the following changes will come into effect on Tuesday 6 August 2026:
introduction of the new 0.2 hectare exemption, which means that the smallest developments will not be required to do mandatory BNG introduction of a new temporary development exemption, for land which is to be reinstated within a period of 5 years or less modification of the biodiversity gain hierarchy for minor development, meaning that minor sites which aren’t exempt from BNG (e.g. over 0.2 hectares) can choose to go straight to offsite in the first instance removal of the existing exemption for self and custom build developmentThe regulations are accompanied by an Explanatory Memorandum (which explains the purpose and effect of the regulations). We have also updated guidance pages to reflect the changes. And we have published an impact assessment, which provides a detailed, evidence-based assessment of the proposed exemption of small development sites from the mandatory BNG requirement.
The Government considers that these changes will help to reduce the burdens on the smallest developers and local authorities. This will benefit the whole BNG system by focusing resources on larger development, which has the greatest impact, and therefore the potential to deliver the greatest benefits to nature.
It is important to note that though we are reducing the BNG burden for the smallest developments, we would still expect these developments to look to incorporate nature friendly features.
And following these changes, developments exempt from mandatory BNG will still be subject to existing environmental protections and policies. Planning decisions should still apply the mitigation hierarchy and refuse permission where significant harm to biodiversity cannot be avoided, adequately mitigated or, as a last resort, compensated.
Transitional arrangements
The regulations and accompanying material clarify when the new exemptions and changes to the mitigation hierarchy apply, including for variations to planning permissions. Broadly, the changes only apply to new applications for planning permission made from 6 August. To note, planning permissions and applications for permission already submitted will continue to be subject to existing BNG legislation.
The government will shortly update planning practice guidance to provide further information to support implementation of these changes.
What next?
Once these changes have come into effect on 6 August, we will continue to work to bring forward the rest of the changes for BNG which we announced in our government response published in April.
This will include:
introduction of an exemption for development whose primary objective is to conserve or enhance biodiversity introduction of a targeted exemption for development that enhances parks, playing fields and public gardens changes to the statutory biodiversity metric (as set out in more detail in our previous blog)Brownfield consultation
The consultation on a potential additional targeted exemption for certain residential brownfield development closed on 10 June 2026. We thank all those who have responded.
All responses and evidence submissions are being analysed and the Government will respond to the consultation in due course.
seen at 10:30, 14 July in Environment.