New mandatory biodiversity net gain regulations take effect

Posted: 12/02/2024

The much-anticipated biodiversity net gain (BNG) regulations have today come into force. Originally scheduled for January, their implementation follows a short delay in parliament introducing the necessary legislation to give effect to the new framework.

New planning applications for major developments submitted from 12 February 2024 (or for small sites from 2 April 2024) will be subject to a mandatory condition requiring BNG of at least 10%. 

Any pending planning applications submitted prior to 12 February 2024 are not subject to this mandatory condition, nor are new applications submitted under section 73 of the Town and Country Planning Act 1990 to vary an existing planning permission granted prior to 12 February 2024.

Even though technically a post permission matter, BNG must be considered at an early stage as local planning authorities (LPAs) will need to have an understanding during the application stage of how BNG will be delivered.

Key components of BNG that need to be taken into account are:

• biodiversity gain hierarchy: enshrined in the new framework, which requires developers to try to avoid the adverse effects of development on on-site habitat altogether. If this is not viable, then developers should be looking to achieve their BNG obligations by focusing on other on-site measures including mitigating such adverse effects, providing habitat enhancement or creating on-site habitat. Early engagement with an ecologist will allow developers to incorporate such measures into the design of the development. If on-site measures cannot be achieved, then developers should consider purchasing off-site units which must be recorded on the biodiversity gain site register prior to submitting the biodiversity gain plan, or as a last resort, purchase biodiversity statutory credits;
• the biodiversity gain plan: this will set out the methodology for achieving BNG and  needs to be submitted to and approved by the LPA before commencement of development;
• the BNG metric: to achieve BNG, a development must result in a sufficiently higher biodiversity unit score post-development as measured by a statutory metric. Engaging with an ecologist at an early stage of the development process will allow developers to measure the pre- and post-development bio-diversity site values and prepare the biodiversity gain plan accordingly; and
• ongoing management and maintenance obligations: BNG works must be managed and maintained for at least 30 years. Responsibility for management and maintenance will vary depending on whether BNG is being delivered on-site or off-site. Such obligations may be recorded in a BNG agreement and will also be subject to a section 106 agreement. Developers should seek legal advice to carefully consider the drafting of these agreements.

Landowners with excess land are encouraged by the government to consider selling off-site BNG units to developers. This is a complex exercise requiring bespoke advice and drafting.  

The planning team at Penningtons Manches Cooper has experience in dealing with BNG agreements, associated section 106 obligations and in selling off-site BNG units to developers, and is able to provide advice or act on behalf of anyone needing assistance in this field.

For more information on BNG, please see this recent article, Mandatory biodiversity net gain comes into force in 2024: what is the new framework and how will it affect developers? 

Return to news headlines