The government has introduced a requirement for certain types of development to deliver a minimum of 10% Biodiversity net gain (BNG). BNG is a way of creating and improving natural habitats. BNG makes sure development has a measurably positive impact (net gain) on biodiversity, compared to what was there before development.
We require a minimum 10% of BNG to be delivered on most sites (excluding exceptions below and small sites). Exceptions apply to:
- Household applications.
- Small scale self build and custom housebuilding.
- Impact of development on habitat of an area below a de minimis threshold of 25 square metres or 5 metres linear habitats, such as hedgerows and watercourses.
- Biodiversity gain sites (where habitats are being enhanced for wildlife).
From 2024, it is anticipated a minimum of 10% will also be required from small sites.
We will apply the Department for Environment, food and rural affairs (DEFRA) proposed mitigation hierarchy. This means proposals should seek to avoid biodiversity loss first, adequately mitigate any unavoidable loss and only as a last resort, compensate the loss.
We will use DEFRA's BNG spatial hierarchy and will favour the delivery of BNG on the actual site. Off-site local delivery will only be accepted where it can be demonstrated providing 10% BNG on the site is unachievable. BNG credits should only be used as a last resort.
We will assess biodiversity loss and gain using the latest DEFRA Biodiversity Metrics. Currently, Statutory Biodiversity Metric for most sites and Small Sites Metric for small sites. Talking to us about BNG at the pre-application stage is strongly advised. Any qualifying planning permission will require the submission of a BNG statement including the following information:
- The pre-development biodiversity value.
- Steps taken to minimise adverse biodiversity impacts.
- The proposed approach to enhancing biodiversity on-site.
- Any proposed off-site biodiversity enhancements (including the use of credits) which have been planned or arranged for the development.
The government has produced a biodiversity metric which developers must use to calculate a minimum 10% gain on the pre-development biodiversity value of the site. The metric calculates biodiversity units based on the habitats on the site or proposed to be created. Achieving 10% net gain means fully compensating for losses of habitat on a development site, but then going further so overall, there is a gain in biodiversity units of at least 10% as a result of the development process.
There is guidance about using the biodiversity metric on the government website.
The provision of BNG will be conditioned or will form part of any S106 agreement related to the planning permission.
More information is available from the following websites: