Type of Habitat | Score | Special Notes |
Irreplaceable Habitats | n/a | Blanket bog, Lowland fens, Limestone pavements, Coastal sand dunes, Ancient woodland, ancient trees and veteran trees |
Very High Distinctiveness Habitats | 8 | This includes priority Habitats as defined in Section 41 of the Natural Environment and Rural Communities (NERC) Act that are highly threatened, internationally scarce and require conservation action, for example blanket bog. Small amount of remaining habitat with a high proportion unprotected by designation. Critically Endangered European Red List habitats |
High Distinctiveness Habitats | 6 | This includes priority Habitats as defined in Section 41 of the NERC Act requiring conservation action, for example lowland fens. Remaining Priority Habitats not in very high distinctiveness band and other Near Threatened and Vulnerable Red List habitats. |
Medium Distinctiveness Habitats | 4 |
|
Low Distinctiveness Habitats | 2 |
|
Very Low Distinctiveness Habitats | 0 |
|
Site Selection
Make sure that, if there are any
Irreplacable Habitats
Irreplaceable habitats are valuable habitats which are technically very difficult or take a very significant time to restore, recreate or replace once destroyed. Paragraph 186(c) of the National Planning Policy Framework provides strong policy protections for irreplaceable habitats when determining planning applications: development resulting in the loss or deterioration of irreplaceable habitats should be refused unless there are wholly exceptional reasons and a suitable compensation strategy exists. The Framework’s Glossary provides a definition of irreplaceable habitats for this policy.
There are specific provisions for the treatment of irreplaceable habitats within the statutory framework for biodiversity net gain. It is recognised that the environmental cost of such loss or deterioration cannot adequately be captured by the biodiversity metric alone. For these reasons, the statutory framework for biodiversity net gain treats irreplaceable habitats differently.
The Biodiversity Gain Requirements (Irreplaceable Habitat) Regulations 2024 define and list irreplaceable habitats for the purposes of biodiversity net gain. If these irreplaceable habitats form part of the development site, there are special modifications for the content and approval of the Biodiversity Gain Plan.
Although irreplaceable habitats are still included within the calculation of the pre-development and post-development biodiversity value of the onsite habitat, they will not be assigned a value unless there is an enhancement proposed to the habitat. So they will not usually contribute to the achievement of the biodiversity gain objective of at least a 10% gain.
However, the Biodiversity Gain Plan must include information about how any adverse effect on the irreplaceable habitat has been minimised and any compensation plan if there are any adverse effects. The planning authority may only approve the Biodiversity Gain if they are satisfied that the adverse effect of development on the irreplaceable habitat is minimised and that appropriate arrangements have been made for the purpose of compensating for any impact. The arrangements are only appropriate if they secure a compensation plan relative to the baseline habitat type and which do not involve the purchase of biodiversity credits.
The statutory biodiversity metric applies to irreplaceable habitats as set out below:
All irreplaceable habitats must be recorded within the metric tool. The statutory biodiversity metric will not calculate the biodiversity value of irreplaceable habitat impacted by a development and will flag that bespoke compensation is required if this is the case. If irreplaceable habitat is being enhanced, the statutory biodiversity metric will calculate the biodiversity unit value of that enhancement.
Where there are proposed enhancements to the irreplaceable habitat: This must be recorded in the irreplaceable habitats sheet of the metric. It will be included in baseline calculation. As there are no negative effects on the habitat, a bespoke compensation package is not necessary and does not need to be approved. The value of any enhancement can contribute to 10% biodiversity gain requirement in these circumstances.
Where there are no losses or deterioration to the irreplaceable habitats: This must be recorded in the irreplaceable habitats sheet of the metric. The biodiversity value of the irreplaceable habitats is not included in the calculation of pre-development biodiversity value in these circumstances and a bespoke compensation package is not necessary if evidence confirms there are no losses or deterioration to the irreplaceable habitats.
Where there are losses or deterioration to the irreplaceable habitats: This must be recorded in the irreplaceable habitats sheet of the metric. The biodiversity value of the irreplaceable habitats is not included in the calculation of pre-development biodiversity value and a bespoke compensation package needs to be agreed with the planning authority, in addition to the Biodiversity Gain Plan.
Matters relating to the spatial choices for the development which may affect irreplaceable habitats, such as the size and location of buffer zones, are likely to be considered at the planning application stage for a development. Buffer zones themselves will be subject to the 10% biodiversity gain requirement. The Biodiversity Gain Hierarchy may be taken into account as relevant
For further information, see the Department for Environment, Food and Rural Affairs guidance on the biodiversity metric and irreplaceable habitats.
Where is the mitigation hierarchy set out in law?
Where is the mitigation hierarchy set out in law?
The irreplacable habitats
Set out in Articles 37A and 37D of the Town and Country Planning (Development Management Procedure) (England) Order 2015. This hierarchy (which does not apply to irreplaceable habitats) sets out a list of priority actions:
first, in relation to onsite habitats which have a medium, high and very high distinctiveness (a score of four or more according to the statutory biodiversity metric), the avoidance of adverse effects from the development and, if they cannot be avoided, the mitigation of those effects; and
then, in relation to all onsite habitats which are adversely affected by the development, the adverse effect should be compensated by prioritising in order, where possible, the enhancement of existing onsite habitats, creation of new onsite habitats, allocation of registered offsite gains and finally the purchase of biodiversity credits.