The UK government's Biodiversity Net Gain consultation response – what does this mean for developers?

Proposals to oblige developers to deliver minimum BNG as part of their projects may have ramifications for the choice of land acquired and type of developments that will be delivered.

The UK's Mandatory Biodiversity Net Gain (BNG) consultation ran for 12 weeks from January 2022, receiving a total of 590 responses, the majority of which came from Local Planning Authorities (LPAs).

In February 2023, the UK government finally published its long-awaited consultation response.
The response was split into three parts:

1. Defining the scope of the BNG requirement for Town and Country Planning Act 1990 (TCP) development;
2. Applying the biodiversity gain objective to different types of development; and
3. How the mandatory BNG requirement will work for TCP development.

Below, we have set out what the new BNG requirements may mean for developers.

What development will be subject to mandatory BNG?

From November 2023 (exact date to be confirmed), most new development that results in a loss of habitat must provide a mandatory BNG of at least 10%, to be maintained for at least 30 years. This includes change of use schemes, although sites which are already covered in 'existing sealed surfaces' will have a zero baseline score therefore BNG will not be required in practice.

'Small sites' (defined as set out below) will have to provide BNG from April 2024.

Small sites are:

• Residential schemes of nine dwellings or fewer on sites of 1 hectare or less / if dwelling numbers are unknown sites of half a hectare or less; and
• Non-residential schemes where the site area is 1 hectare or less / where the floorspace created will be 1,000 sqm or less.

National Strategic Infrastructure Projects will also be expected to provide BNG but this requirement will not apply until November 2025.

It is important to note, not all development will be required to deliver BNG – the exemptions are as follows:

1. Schemes which impact small habitats (25 sqm or 5m for linear features, e.g. hedgerows);
2. Householder applications;
3. Biodiversity gain sites; and
4. Custom housebuilding and small scale self-builds.

However the consultation response hints that exempt development (described above) may still be required to provide biodiversity enhancements.

What does this mean for developers?

In addition to an application for planning permission, a BNG statement will need to be submitted and approved by LPAs. However, exactly what the BNG statement needs to cover is unclear at the moment.

We know that enhanced due diligence to assess whether BNG is achievable onsite will need to be undertaken when acquiring development sites – ultimately increasing costs. Ecologist reports will be needed for onsite provision and legal agreements for offsite biodiversity units for offsite provision.

Government guidance provides that onsite provision will always be preferable, however, where offsite provision is permitted, this should be acquired locally where possible. Developers can provide a combination of onsite and offsite gains to meet the mandatory BNG requirement.

Offsite biodiversity land will also need to be registered with Natural England who will maintain a Biodiversity Gain Site Register recording all offsite biodiversity land sites.

Note, applications to register these sites will take around six weeks and the legal agreement to secure the delivery of the BNG will need to be entered into prior to registration. We await guidance on what is expected to be included in such agreements.

It has been a concern to developers that mandatory BNG will apply to Section 73 TCP applications granted after November 2023. The government guidance provides that, subject to further engagement, BNG conditions will only apply where the original planning permission was granted after November 2023.

When will the BNG need to be delivered?

The BNG statement will need to be approved prior to commencement of development.

It is proposed that the provision of the BNG will be required within 12 months of commencement of development or before occupation, however detailed guidance from the Government on this will follow.

We expect to see guidance published over the coming months which will hopefully fill in any gaps, however in the meantime if you have any questions about what the mandatory BNG may mean for you, please do not hesitate to contact the planning team at Fieldfisher.