In England, biodiversity net gain has been required for all major development since 12 February 2024 and for small sites since 2 April 2024 (with some exceptions). Within the statutory framework, planning permission is deemed to have been granted subject to the condition that the biodiversity gain objective must be met, the objective being to ensure delivery of at least a 10% increase in biodiversity value relative to the pre-development biodiversity value of the onsite habitat.
Exemptions to the 10% biodiversity net gain objective
There are specific exemptions from the requirement to provide biodiversity net gain and from the 6 August onwards, the following exemptions will be added:
NEW: exemption for developments of sites of 0.2 hectare or less where no onsite priority habitats are impacted (regulation 7A)1 ;
NEW: exemption for temporary development, only if it does not impact onsite priority habitat, consists solely of temporary development, and is subject to a requirement that the development is removed and the land reinstated within a period not exceeding 5 years. This exemption would also not apply if a series of permissions are granted for the same temporary development resulting in a period exceeding 5 years (regulation 7B)2.
The following exemptions remain applicable:
De minimis exemption
Householder applications
High speed railway transport network
Biodiversity gain site.
Both new exemptions only apply to applications made after the 6 August 2026. The exemptions do not apply to section 73 planning permissions where the related original planning permission was applied for or granted before 6 August 2026.
What do the changes mean?
There is no longer an exemption available for custom and self-build developments unless permission was granted prior to 6 of August 2026 or they are carried out pursuant to a section 73 permission where the original planning permission was exempt by virtue of the self and custom build exemption.
Amendments to the biodiversity gain hierarchy for non-major development
There is also an easing of the biodiversity gain hierarchy for minor development to make it easier for these developments to access offsite biodiversity gains. The insertion of article 37A (c) to the Town and County Planning (Development Management Procedure) (England) Order 2015 results in habitat enhancement of onsite habitat, creation of onsite habitat or the availability of registered offsite biodiversity gain for allocation to that development being treated at the same level of preference in the hierarchy for non-major development. There is still the “last resort” option of purchasing biodiversity credits where none of these are possible.
This amendment to the hierarchy only applies to applications made after 6 August 2026.
The Government have amended the Planning Policy Guidance in relation to Biodiversity net gain to explain these amendments and provide guidance which is available here Biodiversity net gain.
