Biodiversity for Nationally Significant Infrastructure Projects (NSIPs)

Biodiversity net gain (BNG) for Nationally Significant Infrastructure Projects (NSIPs) will be in force from November 2025. So with a long lead-in time for many NSIPs, they should be aware of the requirements and plan accordingly well in advance.

What is the government's current plan?

The Environment Act made amendments to the Planning Act 2008 which introduce a requirement that, development consent for NSIP projects cannot be granted unless any Biodiversity Gain Statement, which exists either through an NPS or as a separate parliamentary statement, is complied with.

BNG requirements under the Town and Country Planning Act 1990 (TCPA) came into force for most developments on 12 February 2024.

When BNG requirements for NSIPs come into force, it is anticipated that they will broadly align with the requirements for applications made pursuant to the TCPA, particularly in six key areas:

Scope, percentage, and targeted exemptions: no broad exemptions will apply other than the provision for development on irreplaceable habitats. This approach will be aligned with that of other types of projects.

Setting the requirement and transition arrangements through ‘biodiversity gain statements’: it has been confirmed that the requirement for BNG will come into force in November 2025.

NSIP off-site gains and a ‘portfolio approach’: NSIP off-site gains will need to be recorded in a biodiversity gain site register, as is the case for developments under the TCPA.

Process and demonstrating biodiversity net gains: developers or scheme promoters will need to prepare a form of biodiversity gain plan and a completed biodiversity metric. Where habitats have been degraded since January 2020, the pre-degradation habitat should be taken as the baseline.

There will be no distinction for NSIPs between on-site habitats - which are subject to BNG - and any dedicated environmental mitigation areas included in the project boundary. This is consistent with the TCPA approach for development.

Maintenance period for NSIPs: the minimum duration for BNG maintenance will initially be set at 30 years. This may be extended after review in the same way as under the TCPA.

Compulsory acquisition: guidance will be provided in biodiversity gain statements that outlines the reasonable alternatives developers should explore to deliver net gain before they consider compulsory acquisition of land.

As noted above, it is envisaged that developers will submit a biodiversity gain plan with their applications, and BNG enhancements would then be secured by Requirements in the development consent order (DCO). 

The new National Policy Statements are becoming firmer on the approach for BNG. For example, a newly introduced paragraph in the recently finalised National Networks National Policy Statement (NNNPS) states: "A government biodiversity gain statement will set out the concept and policy requirements for biodiversity net gain for [NSIPs]. When these provisions are commenced, the secretary of state will need to be satisfied that the biodiversity gain objective in any relevant biodiversity gain statement has been met."

Applications ancillary to an NSIP

Whilst intended to be a 'one-stop-shop', practically there may be occasions where separate planning applications are submitted to support or slightly tweak areas of associated development within a wider DCO.

Promoters should be aware that even though they are, in practice, linked to an NSIP development, because they form their own standalone planning application, they will need to adhere to BNG requirements for all planning applications under the TCPA regime.

However, it will be of small comfort that permitted development is not subject to BNG requirements.

What next?

The government has said it will consult on a biodiversity gain statement with a view to finalise it later. It is likely there will be more evolutions of the guidance and plans before the BNG requirement for NSIPs comes into force.