Biodiversity Net Gain (BNG) Now Mandatory

From this week, the 12th February 2024 to be more specific, Biodiversity Net Gain (BNG) became mandatory for major developments, with certain exemptions, and development of ‘small sites’ will be added to this requirement from 2nd April.

So, what is BNG?  It is a way of securing different ways to support the recovery of the natural environment whilst developing sites.  It means, in terms of its overarching objective, that habitat should be in a better state than it was prior to development. The concept of BNG is one which has been in the pipeline for some time given that it was first introduced within the National Planning Policy Framework 2012 (the first, and original, version of the Framework) and this was then made mandatory through the Environment Act in 2021.  Indeed, some local planning authorities have already been requesting varying levels of BNG through their local plan policies – some already exceed the required 10%.

The basic components for BNG were set out within the Environment Act 2021.  These include, but are not limited to, making relevant amendments to the Town and Country Planning Act 1990, setting out that a minimum 10% gain is required (calculated using the biodiversity metric and approval of a biodiversity gain plan at planning application stage) and that delivery can be on site, off site or via statutory biodiversity credits scheme.

BNG will, therefore, now affect all planning applications going forward within the planning process as they are submitted after the relevant dates. Biodiversity value is calculated using the statutory biodiversity metric which is published by Defra.  This essentially assess is habitat type, size, distinctiveness, condition and location and in respect of planning applications there must be a net increase of at least 10% biodiversity units post development compared to predevelopment.

This means, therefore, that the biodiversity metric calculation will need to be submitted as part of the biodiversity gain plan which will need to be approved by the local planning authority and no development can commence until the plan is approved.  Whilst it is already common practice, with in most applications, to employ an ecologist (in relation to preliminary ecological appraisals and more species-specific surveys) this involvement is now likely to need to also extend to giving advice on completion of the required metric.

From the 12th February it is a mandatory requirement to provide BNG of at least 10% for new planning applications which will include proposals which are for the provision of dwelling houses where the number of dwelling houses to be provided is 10 or more or the provision of a building or buildings where the floor space to be created is 1000 square metres or more or the development will be carried out on a site having an area of 1 hectare or more.  Applications submitted prior to the 12th of February are not caught by the legal requirements.

For small sites the proposed mandatory BNG requirement applies from the 2nd of April and a specific tool for sites of this nature has been developed.

There are some exemptions for certain types of development which include, but are not limited to, permitted development, certain householder development and self-build and custom build development which is for 9 dwellings or less with a site which does not exceed 0.5 hectares.  Applications made for permission to develop without complying with their condition/ conditions previously imposed on a planning permission (more commonly known as a condition variation) will be subject to the mandatory requirement within the legislation.  This applies even if the original permission predates the requirement for BNG.

We will be contacting any existing instructions which are likely to be affected by these requirements as appropriate (as well as flagging this with new enquiries/fee quotes) and will, as always, direct clients/applicants to appropriate advice to support their development and application requirements going forward.  It is certainly going to be an interesting few months as everyone gets up to speed with preparation and application of this new legislation to development projects going forward.