A mandatory 10% BNG will only apply to new applications for planning permission for major development made after January 2024. Mandatory BNG should not be applied retrospectively to planning applications that have been submitted or have already been granted permission before January 2024. BNG has been a national policy consideration for a while but has been a matter to be balanced against other material considerations until now.
As defined by the Government, BNG is a way of creating and improving natural habitats, to make sure development has a measurably positive impact (‘net gain’) on biodiversity, compared to the position prior to development.
This means that by law developers must deliver a net positive for the local environment, for example by creating new habitats and green spaces. BNG for small sites will be applicable from April 2024 and implementation for Nationally Significant Infrastructure Projects remains planned for 2025.
BNG was introduced through the Environment Act 2021 which inserted a new Schedule 7A into the Town and Country Planning Act 1990, which puts into place the framework against which BNG will be delivered.
In simple terms, BNG is measurable in standardised 'biodiversity units', of which a habitat will contain a number of, depending on its size, quality, location, type and other factors. Biodiversity units can be lost through development or can be generated by work to create and enhance habitats.
A statutory biodiversity metric has been devised, to which a downloadable statutory biodiversity metric tool can be used as a calculator to apply the statutory biodiversity metric formula.
Government guidance identifies 3 ways in which a developer can achieve 10% BNG as measured by the statutory biodiversity metric. Developers can combine all 3 options, but must follow the steps in order. These steps are as follows:
- They can enhance and restore biodiversity on-site (within the red line boundary of a development site).
- If developers can only achieve part of their BNG on-site, they can deliver through a mixture of on-site and off-site. Developers can either make off-site biodiversity gains on their own land outside the development site, or buy off-site biodiversity units on the market.
- If developers cannot achieve on-site or off-site BNG, they must buy statutory biodiversity credits from the government. This must be a last resort. The government will use the revenue to invest in habitat creation in England.
For significant on-site gains, and all off-site gains, the BNG must be maintained for at least 30 years.
In applying for planning permission, if a proposed development is not exempt for BNG, a statutory biodiversity metric tool calculation is needed to be submitted to state a site's biodiversity value prior to development. Information should also be provided setting out how the BNG objective will be met. A legal agreement (such as a s.106 agreement or conservation covenant) or a habitat management plan and monitoring plan may also be required.
If planning permission is granted, a biodiversity gain plan will need to be prepared by the developer. The local planning authority must approve the biodiversity gain plan before development is commenced.
Where applicable, the 30 year period of BNG management and maintenance commences from the time the agreed initial habitat creation or enhancement is completed.
If BNG obligations are not met, enforcement action can be taken for breaches by the local planning authority.
