Follow us

Developers and promoters should be making steps to ensure nationally significant infrastructure projects comply with new biodiversity net-gain requirements.

The Environment Act 2021 (EA 2021) introduced a new requirement for the delivery of mandatory biodiversity net gain under both the Town and Country Planning Act 1990 (TCPA) and the Planning Act 2008 (PA 2008). A consultation by the Department for Environment, Food and Rural Affairs (Defra) provides more detail on how the new requirement will work, including how and when it will be applied to TCPA development and Nationally Significant Infrastructure Projects (NSIPs).

The introduction of a biodiversity net gain requirement for NSIPs was a late addition to the EA 2021. These requirements are therefore less well developed than the biodiversity gain requirements for TCPA development. The Defra consultation considers core policy rather than detailed application, and the detail will be the subject of future consultation.

Here we discuss which NSIP developments will be affected, when the requirements are anticipated to come into force and what steps promoters should be taking now.

Which developments will be affected?

This is set out in section 99 and Schedule 15 to the EA 2021, which amend sections 103 to 105 of the PA 2008 and insert a new Schedule 2A.

If a project is subject to a National Policy Statement (NPS) and that NPS includes a “biodiversity gain statement”, or if a biodiversity gain statement otherwise applies to the project, the Secretary of State must decide the application in accordance with the biodiversity gain statement.

The UK government intends to design a single "core" statement which will be consulted upon for a range of NSIPs, although some types of projects may require bespoke statements. The biodiversity gain statement, or statements, will be published as standalone policy documents and subsequently integrated into the NPSs when they are reviewed.

Whilst there is less certainty about the mechanism for biodiversity net gain with NSIPs, the approach to measuring the pre-development and post-development value is expected to be broadly the same as for development under TCPA, as is the manner in which the biodiversity gain objective may be achieved. The intended minimum biodiversity net gain to be required is stated to be 10%, but it also identified that there may be cases when some types of NSIPs are unable to deliver a 10% gain and a different percentage requirement may be applied.

When will the biodiversity net gain requirements come into force?

Terrestrial development

For terrestrial development consented under the PA 2008, the mandatory biodiversity net gain requirement should commence no later than 2025 for all projects accepted for examination through the NSIP regime, and the requirement may be imposed earlier in relation to certain types of infrastructure if an earlier commencement date is identified to be achievable.

Projects which have been accepted for examination by the Planning Inspectorate before the specified commencement date would not be required to deliver mandatory biodiversity net gain, ensuring projects which are at a sufficiently advanced stage do not need to then identify scheme amendments (and potentially additional land) to meet the mandatory net gain requirement.

To give developers, planners, and ecologists sufficient time to plan to deliver biodiversity net gain on projects consented through PA 2008, the UK government will also publish biodiversity gain statements at least two years before the requirement takes effect in November 2025 for the relevant projects (ie no later than November 2023). If earlier commencement than November 2025 is considered achievable and is specified for certain projects, the relevant biodiversity gain statement will be published at least two years before that date.

Marine environment

Projects, or components of projects, in the marine environment beyond the intertidal zone are not currently included within the scope of the mandatory biodiversity net gain requirements. However, the EA 2021 provides options for introducing such a requirement in the future and Defra are understood to be working towards a consultation on the principles for marine net gain later this year.

"Promoters should factor in the biodiversity gain objective when identifying Order limit boundaries and consider their response to biodiversity policy requirements which are applicable now."

What can applicants be doing now?

The delivery (or non-delivery) of biodiversity net gains is a politically sensitive topic, particularly for major developments and for projects being consented through the PA 2008 regime. Applicants should therefore identify how they can maximise biodiversity net gains in their development proposals prior to the transitional periods expiring and the legal requirements for mandatory net gains coming into effect.

For projects consented through the PA 2008, it may be possible to include additional land within the proposed Order limits to provide the biodiversity net gains required and for such land to be subject to compulsory acquisition pursuant to the relevant DCO where the relevant statutory tests for this are shown to be satisfied. There is an expectation that developers should deliver further gains within the 'existing project boundary', or through the purchase of market offsite biodiversity gains, without resorting to additional compulsory acquisition. With this being the case it will be important that any land to deliver biodiversity net gains is identified as early possible and ideally before statutory consultation commences.  

Key contacts

Martyn Jarvis photo

Martyn Jarvis

Senior Associate, London

Martyn Jarvis

Stay in the know

We’ll send you the latest insights and briefings tailored to your needs

London Environment, Planning and Communities Infrastructure Martyn Jarvis