Development likely to result in the loss or deterioration of irreplaceable habitats or protected sites will not be permitted unless there are wholly exceptional reasons, in line with Local Plan policy CE-S3.
Impacts on irreplaceable habitats are not adequately addressed by the metric and it should not be used for this purpose.
With reference to the Defra guidance and BNG Regulations (2024), the following habitats are considered irreplaceable:
Ancient woodland
Ancient and veteran trees
Blanket bog
Limestone pavements
Coastal sand dunes
Spartina saltmarsh swards
Mediterranean saltmarsh scrub
Lowland fens
Outline planning applications should be supported by a BNG Strategy which will show how the development will realistically be able to deliver BNG based on the land available for different uses. For phased developments, the Strategy should show how each phase will deliver a pre-determined proportion of habitat provision for BNG.
Where the general biodiversity gain condition applies, a Biodiversity Gain Plan will need to be submitted no earlier than the day after planning permission has been granted. The Environment Act 2021 states that the plan should include:
How adverse impacts on habitats have been minimised
The pre-development biodiversity value of the onsite habitat
The post-development biodiversity value of the onsite habitat
The biodiversity value of any registered off-site habitat provided in relation to the development
Any statutory biodiversity credits purchased
Any further requirements as set out in secondary legislation
A plan/map should be provided as part of the Biodiversity Gain Plan showing clearly where habitats will be protected, enhanced and created. Where development is not to proceed in phases, additional information is required as set out in the Planning Practice Guidance1. There is a standard Biodiversity Gain Plan template which may be used.
Development may not commence until the Biodiversity Gain Plan has been approved.