Biodiversity net gain: Development Consent Orders and compulsory purchase

Earlier in 2024 Biodiversity Net Gain (BNG) requirements for planning permission were implemented under Schedule 7a of the Town and Country Planning Act 1989 – from 12 February 2024 for major sites, and from 2 April 2024 for small sites. Despite this progress, however, there remains a large gap regarding the implementation of BNG as a requirement for Nationally Significant Infrastructure Projects (NSIPs) under Development Consent Orders (DCOs).

Schedule 15 of the Environment Act 2021 sets out the prospective BNG provisions which will apply to DCOs once they are implemented. The key points to note are:

• The Secretary of State must make a BNG statement containing a BNG objective, which will apply to all DCOs during a specified period
• The statement must require a BNG value increase of at least 10%, mirroring the required gain for planning permission, though the Secretary of State has the power to make a BNG statement requiring additional BNG
• The statement must make provision that if a DCO includes land already registered on the BNG register, the value of predevelopment habitat for the purposes of the DCO includes the value of the existing habitat enhancement
• The statement must set out whether and how the BNG objective applies to irreplaceable onsite habitat
• The statement must set out what evidence is required from any DCO applicants to demonstrate how the BNG objective is met.

There are subsequent provisions which set out procedure, if any developments are, or are not, covered by an existing national policy statement at the time at which Schedule 15 is implemented.

Acquisition of land for BNG purposes

In a decision letter dated 12 September 2024, a DCO was granted to National Grid for the upgrading of infrastructure running from Suffolk to Essex, known as the Bramford to Twinstead Reinforcement and associated development. Interestingly, this DCO dealt with BNG considerations for the NSIP, ahead of the requirements becoming mandatory.

National Grid argued that whilst BNG was not mandatory for NSIPs, within their 2021-2026 Environmental Action Plan, they had committed to delivering at least 10% or greater value on BNG in that period, and as such, it formed part of their application for the DCO.

The decision letter confirmed that whilst the government intends to commence mandatory BNG for NSIPs from November 2025, it supported National Grid’s decision to commit to BNG on a voluntary basis ahead of the mandatory requirement being introduced.

Further, the Secretary of State used their discretionary power to grant compulsory purchase powers under a DCO pursuant to s122 of the Planning Act 2008, to give National Grid the power to acquire compulsorily, land it needed for its BNG requirements, in the event that voluntary agreements, with those whose interests it needed to acquire, could not be reached.

What this means for Landowners & Tenants

The implications of this decision are quite stark in respect of compulsory purchase; landowners will now need to concern themselves with developments, not only where their land may be required for the direct development of an NSIP, but also where their land is not directly required, but rather has simply been identified as suitable BNG land to support the NSIP.

Should you wish to discuss any of the issues raised in this article, please contact Adrian Bennett.