6 August update: The new exemptions have come into force. The Planning Practice Guidance has now been updated to reflect the changes.
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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 Thursday 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 (unless onsite priority habitat is negatively impacted)
- introduction of a new temporary development exemption, for land which is to be reinstated within a period of 5 years or less (unless onsite priority habitat is negatively impacted)
- 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 development
The 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 biodiversity gain 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.
34 comments
Comment by Matt H posted on
Are councils still going to ask for section 106 agreements on current (transitional) applications that are self build and less than 0.2ha?
Comment by bethcarnell posted on
Hi Matt,
Thanks for getting in touch. To confirm, until the changes come into force on 6 August 2026, local planning authorities will continue to apply the current BNG rules when assessing planning applications.
Thanks,
Beth
(The Defra Environment Blog team)
Comment by Louise Cutts posted on
So, is it intended that self-builds will now be exempt only if the site is less than 0.2ha, rather than excluded from the exemption completely.
Comment by bethcarnell posted on
Hi there,
From 6 August 2026, the existing self-build and custom build exemption will be removed for new applications but other exemptions may apply, including the new exemption for development up to 0.2ha.
Hope that helps.
Thanks,
Beth
(The Defra Environment Blog team)
Comment by Stuart Talbot posted on
For an application which is submitted prior to the 6th August and therefore subject to BNG were refused on BNG grounds.
If the application would meet the new exemptions. Should an appeal be received after the 6th August would the Inspector apply the BNG requirement or would they assess it under the new exemptions.?
Comment by bethcarnell posted on
Hi Stuart,
We cannot advise on individual planning applications. You may wish to seek individual legal advice, or speak to your Local Planning Authority.
Best,
Beth
(Environment Blog Team)
Comment by Grant Arnold posted on
Why is not being back dated to undeveloped sites that still have the burden on BNG within the planning conditions.
Comment by bethcarnell posted on
Hi Grant,
Transitional arrangements are in place to ensure that planning applications that are already in the planning system continue to be considered under the rules that were in place when the application was made, and that new applications, made from 6th August are assessed against the new rules. This date is set in law and provides clarity for developers and local planning authorities when assessing applications.
Thanks,
Beth
(The Defra Environment Blog Team)
Comment by w t Wright posted on
Hi
As a developer , we have a site for two new detached housing under construction. The planning approval was in 2025 and included conditions for BNG with accompanying HMMP.
The site is under .2ha so would be exempt for BNG under the new legislation.
On sale of the properties do we still need to make legal provisions for our
duties under the HMMP i.e. 30 year plan of inspection and maintenance
and will the local authority be looking to monitor and enforce the requirements under the HMMP.
Comment by bethcarnell posted on
Hi,
I've spoken to the BNG team and can confirm BNG requirements should be delivered if BNG applied at the point that the planning application was submitted and approved.
Hope that helps,
Beth
(The Environment Blog Team)
Comment by Tim posted on
Will retrospective applications still be exempt from mandatory BNG?
Comment by bethcarnell posted on
Hi Tim,
Thanks for contacting the blog. I can confirm Retrospective applications are currently out of scope for BNG.
I hope that helps,
Beth
(The Environment Blog Team)
Comment by Gary posted on
Will this mean a BNG report would not be required, for example, a change of use of agricultural land to a residential garden of approximately 500m2 from the new date? But also, if an application has already been submitted, would it be possible to submit a Section 73 application to remove the BNG requirement, or would you have to reapply to the council again?
Comment by bethcarnell posted on
Hi Gary,
All applications under 0.2 hectares (or 2000 square metres) submitted on or after 6th August are exempt from BNG. The Planning Practice Guidance has now been updated to reflect the changes. This includes information on Section 73.
Thanks,
Beth
(The Environment Blog Team)
Comment by Ted Staples posted on
Hi,
If an applicant withdraws their application before 6th August and resubmits after the 6th August as their proposal/site will meet the new exemptions, will the resubmission therefore not be subject to BNG?
Comment by bethcarnell posted on
Hi Ted,
We cannot advise on individual planning applications. You may wish to seek individual legal advice, or speak to your Local Planning Authority.
Best,
Beth
(Environment Blog Team)
Comment by Matt A posted on
Is there a list of priority habitats somewhere?
Comment by bethcarnell posted on
Hi Matt,
I've spoken to the team and they've informed me that:
A priority habitat is a habitat listed by the Secretary of State for Environment, Food and Rural Affairs under section 41 of the Natural Environment and Rural Communities Act 2006. Find more information: https://www.legislation.gov.uk/ukpga/2006/16/section/41
Thanks,
Beth
(The Environment Blog Team)
Comment by Damian H posted on
We have noticed the transitional arrangements notes; 'The government will shortly update planning practice guidance to provide further information to support implementation of these changes'.
When does this hope to happen please? Current planning permissions will need further guidance on this and when is this becoming available? LPA's will surely find themselves inundated with withdrawals and resubmitted applications post the 6th August for current undecided applications. This would add significantly to the natural rate of applications being submitted and place further added strain on the planning service.
Is further guidance to be issued before the 6th August?
Comment by bethcarnell posted on
Hi Damian,
The Planning Practice Guidance has now been updated to reflect the changes.
Please visit: https://www.gov.uk/guidance/biodiversity-net-gain
Beth
(The Environment Blog Team)
Comment by Penny Little posted on
can you clarify if it would be possible to apply to remove a condition to provide BNG calculations after 6th August if the development has not started?
Comment by bethcarnell posted on
Hi Penny,
We cannot advise on individual planning applications. You may wish to seek individual legal advice, or speak to your Local Planning Authority.
Best,
Beth
(Environment Blog Team)
Comment by Winnie posted on
Does this mean if we're doing an extension to an existing building which is less than 0.2ha, it is now exempt? For example, does the exemption use the area of the red line boundary, or does it include the site as a whole?
Comment by bethcarnell posted on
Hi Winnie,
I have spoken to our team. They have informed me:
It is determined by the red line boundary so a new planning application under 0.2ha would be exempt. For larger sites, you may want to consider if any other exemption applies.
I hope that helps,
Beth
(The Environment Blog Team)
Comment by Melanie M posted on
So what if I made a planning application before BNG was a thing , however due to time lapse ( no fault of mine )the council granted the application after BNG was introduced , however I still have a time frame for everything to be signed off and now BNG isn’t a thing ? It’s so confusing , Am I still liable for BNG ?
Comment by bethcarnell posted on
Hi Melanie,
I've spoken to the BNG team, they've confirmed:
Any planning applications for developments made before BNG came into force on 12 February 2024 are exempt from BNG (if it is a minor development, then this applies for all minor developments made before 2 April 2024). For applications submitted after those dates, BNG requirements will still apply if BNG applied at the point of application. The 0.2 hectare exemption and the temporary development exemption only apply for applications for planning permission made on or after 6 August 2026.
Hope that helps,
Beth
(The Defra Environment Blog Team)
Comment by Sandip Sahota posted on
Can developers with existing planning permissions which require BNG apply to remove the requirement through a s.73 application ?
Comment by bethcarnell posted on
Hi Sandip,
All applications under 0.2 hectares (or 2000 square metres) submitted on or after 6th August are exempt from BNG. The Planning Practice Guidance has now been updated to reflect the changes. This includes information on Section 73.
Hope that helps,
Beth
(The Environment Blog Team)
Comment by Elle posted on
Hi Beth, We build equestrian arenas, for any currently in planning they are not included from the new exemptions? New applications are, but still councils will put them through the process, it's just the cost? Thanks for clearing it up.
Comment by bethcarnell posted on
Hi Elle,
The new exemptions apply to all development types from 6th August, should that development qualify for an exemption. So an equestrian arena, or any other type of development under 0.2 hectares would be able to claim the exemption.
Thanks,
Beth
(The Defra Environment Blog Team)
Comment by Emily posted on
For an existing planning consent where work has not commenced, can we apply for the planning condition related to BNG to be removed where the site area is below 0.2ha?
Comment by bethcarnell posted on
Hi Emily,
As referenced in the blog, the new rules apply to applications for planning permission made from 6th August. For applications made before that date the new exemptions don't apply.
Thanks,
The Environment Blog team
Comment by Tom B posted on
My understanding was that the exemption relating to temporary impacts to habitat with a return to condition in 2 years would be maintained? This seems to have disappeared from the guidance. The exemption for temporary development for 5 years is not the same thing as a permanent planning application with a temporary habitat impact (e.g. installing a pipe).
Comment by bethcarnell posted on
Hi Tom,
I've spoken to the BNG team and they've informed me that the metric user guide contains guidance on how to account for temporary losses in the metric - this rule hasn't changed and is separate from the exemption for temporary development.
There is more information available at https://assets.publishing.service.gov.uk/media/6a1d98e9c7335e2ca6daadd5/The_Statutory_Biodiversity_Metric_-_User_Guide_-_June_2026.pdf
Hope that helps,
Beth
(The Environment Blog Team)