BNG for major infrastructure projects consultation requires careful consideration

Matt Fox, Imogen Dewar and Claire Brodrick of Pinsent Masons were commenting after the Department for Environment, Food & Rural Affairs (Defra) published its consultation on BNG for NSIPs (44 pages/ 532 KB) outlining how major infrastructure projects – such as roads, railways, and energy networks – will be required to deliver a minimum 10% net gain in biodiversity. The launch of the consultation is accompanied by an announcement that the introduction of the regime will be delayed by six months, to May 2026.

The latest development follows the phased rollout of BNG under the Environment Act 2021, which made it mandatory for most towns and country planning developments in 2024.

Planning and infrastructure specialist Fox of Pinsent Masons said: “While the new document does not provide a suggested approach to all issues, and instead seeks views on them, it is an absolute must read, in full, for developers and other interested parties.”

Defra’s objectives include ensuring consistency with existing BNG rules, supporting the UK’s nature recovery targets, and providing flexibility for complex, linear infrastructure projects.

The consultation proposes that NSIPs will need to submit “biodiversity gain plans” as part of their development consent order (DCO) applications, with requirements to then allow for further development post consent. This differs from the method for non-NSIPs where plans are submitted following consent.

These plans must demonstrate how the project will achieve the required net gain, whether through on-site habitat creation, off-site enhancements, or the purchase of statutory biodiversity credits. It is proposed that DCO Requirements should secure that all or most biodiversity units, including off-site units and credits, are secured before development, or any phase of development is commenced. In addition, any final shortfall in biodiversity units must be secured once the final impact of habitats is known.

In respect of compulsory acquisition powers and BNG, the consultation notes that applicants can deliver BNG on-site or off-site in the first instance, with the purchase of BNG credits to be considered a last resort. This compares to the Town and Country Planning Act focus on the delivery of on-site BNG units as a first priority. The document states that this change would help ensure that applicants are not incentivised to use compulsory acquisition to “further expand their scheme boundaries to try and deliver BNG entirely on-site”. It goes on to say that it is not expected that promoters would need to use compulsory acquisition powers for BNG only land.

The document does not recognise that the nature of NSIPs in development terms is very different from a typical TCPA development. In particular, it does not account for the fact that many projects involve extensive linear and/or underground elements – currently the document does not change the presumption that all permanent land within your site boundary (including easement widths) needs to be considered as part of calculating the pre-development biodiversity value for a project.

Taking all of these points together Fox said that “this means that if this regime is brought into effect in the proposed form, NSIP projects could be left needing to meet extensive BNG requirements which can only be delivered off-site, leading to cost and programme implications in trying to negotiate commercially suitable deals in sufficient time with landowners and BNG brokers”.

Another issue is the interaction with “long-lived” temporary possession of land and how that is dealt with in the BNG regime. “This includes that the government recognises that this needs to be dealt with differently, inviting views on the topic. This is a further key point for the future approach to BNG,” said Dewar, as “utilising temporary possession powers before ultimately determining the precise extent of permanent requirements is a key part of the implementation process for NSIPs which needs to be accounted for in the BNG process”.

The consultation also explores how BNG can be integrated into environmental impact assessments (EIAs) and how long-term habitat management will be monitored and enforced as well as interaction with environmental measures provided for other reasons or under other frameworks which should be treated similarly to the Town and Country Planning Act, seeking to take a similar approach to TCPA.

Brodrick, energy and infrastructure expert at Pinsent Masons, said: “The consultation invites responses from promoters on the likely impacts of the potential proposals”. Given the issues identified above “it will be important for promoters to engage with this consultation and explain the real world complications that the proposed approach could lead to, which could delay, stymie or lead to further taxpayer subsidy being required for much needed infrastructure.”

In a parallel development, deputy prime minister and housing secretary Angela Rayner announced a package of reforms aimed at boosted small and medium-sized housebuilders, including streamlined BNG requirements for minor developments. Under the new proposals, developments of up to nine homes will benefit from eased BNG obligations, while sites of 10 to 49 homes will face simplified biodiversity rules and potential exemptions from the building safety levy. The reforms are part of the government’s “plan for change” to deliver 1.5 million homes and address the housing crisis.