Skip to main content



Corporates and Business Services


Employment and Immigration


Fraud and Investigations






Planning, Infrastructure and Regeneration


Public Law


Real Estate


Restructuring and Insolvency

Home / News and Insights / Blogs / Planning Act 2008 / 930: The Great British biodiversity net gain consultation

Today’s entry reports on the government’s consultation on the implementation of the biodiversity net gain (BNG) requirements.

Readers of this blog will know that under the Environment Act 2021, for DCO applications that have a national policy statement (NPS) in place, if that NPS requires BNG then the DCO cannot be approved unless it provides the requisite BNG (set at 10%). For any NPSs that don’t provide BNG, they must include it the next time they are reviewed. In addition, for DCO applications that don’t have an NPS in place, and for ones that do have one but it doesn’t require BNG yet, the government may issue a ‘biodiversity gain statement’, which is basically a free-standing version of the part of an NPS that would require BNG.

A consultation was launched on 10 January on the details of BNG for planning permissions and DCOs, which closes on 4 or 5 April (see below). The consultation sets out a number of issues which give an idea of how the government is considering implementing these requirements. There is a specific section on nationally significant infrastructure projects (but only their onshore elements down to the low water mark) at pages 39-49 with corresponding questions (numbers 18-27 out of a total of 55). First, at page 42 it seems that the government is proposing a single ‘biodiversity gain statement’ to cover all types of NSIP.

Secondly, on the timing for the application of BNG to DCO projects, the government indicates that it will provide promoters at least two years’ warning before the requirement kicks in, and there is a long stop date of November 2025:

‘We will give developers, planners, and ecologists sufficient time to plan to deliver biodiversity net gain on these projects. We will therefore publish biodiversity gain statements at least two years before the requirement takes effect in November 2025 for the relevant projects (so 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.’

Contrast this with BNG requirement for conventional planning applications, which is to become a requirement by November 2023. It’s not entirely clear but it seems that DCO applications that have been accepted by the implementation date are proposed not to be subject to the BNG requirement. Perhaps an application being made might be a better cut-off, although presumably there will be more than 28 days’ notice of the provisions coming into force so you wouldn’t have the situation of an application being made before, and accepted after, the cut-off without realising that was going to happen.

Thirdly, the government has given an initial endorsement to the ‘estate’ BNG approach for serial promoters of DCOs:

‘National Highways, Network Rail and National Grid have existing organisational plans to increase the number of their projects delivering biodiversity net gain. It may be possible for these and other organisations to make use of their existing estates, or other strategically located land, to meet a biodiversity gain requirement in relation to an NSIP which they are sponsoring. Where appropriate and in line with the mitigation hierarchy, we could explore a system which enables organisations to deliver and transparently report on additional enhancements on their estate to meet the net gain requirement in relation to sponsored NSIPs.’

Given the number of energy promotions on the horizon, its useful that the government seems open to other ‘organisations’ being capable of utilising the ‘estate approach’, in addition to naming specific bodies. This will be useful given that in respect of the calculation of the 10% BNG, the government is considering excluding environmental mitigation already part of the project (Q23). In this context, its also worth noting that the government is consulting on types of projects where BNG need not be provided where such projects ‘are unable to deliver a 10% biodiversity net gain but may be able to deliver a lower percentage target’.

Fourthly, the government is seeking views on compulsory acquisition in the context of BNG. The consultation document sets out:

There may be instances where NSIPs need to deliver gains close to their site but do not have the flexibility to do this. NSIP providers might, in such circumstances, want to use compulsory acquisition powers to extend the boundary to deliver on-site biodiversity gains. However, we expect that it would generally be preferable for developers to deliver further gains within the existing project boundary or through the purchase of market off-site biodiversity gains without resorting to additional compulsory acquisition of land.

The government appear to be stopping short of allowing compulsory acquisition of land purely for BNG in all cases. Guidance from government on what ‘generally be preferable’ and which factors support compulsory acquisition would be helpful.

So far as compulsory acquisition is concerned, it’s worth highlighting some relevant precedents (taken long before the Environment Act 2021 was given Royal Assent). On the Cleve Hill Solar Park project, the Secretary of State seemingly endorsed compulsory acquisition of land which was needed for the dual purpose of biodiversity net gain and mitigation – see paragraph 6.26 of the decision letter which sets out that land could be compulsorily acquired because ‘there is a compelling case for inclusion particularly in view of the additional benefits in respect of biodiversity net gain that the Development would be able to deliver’ (see further paragraph 6.14 for the background).

The second set of precedents are relevant in the compulsory acquisition context and also in the context of the government’s suggestion in the consultation document that the ‘Government does not intend to set a minimum [maintenance] period for [BNG included in] NSIPs that is shorter than the 30-year period specified for other kinds of development’ (with a heavy hint that it could be longer in some cases). This potential 30 year maintenance period gives rise to a consideration of whether the temporary possession powers or compulsory acquisition of permanent rights or indeed outright compulsory acquisition of land is required.

Almost all DCOs contain a five year period to take temporary possession to carry out maintenance though some projects extend this in accordance with the requirements of a management plan (see, for example, article 34(11) of the M25 Junction 10 draft DCO). However, its also worth noting the Secretary of State’s comments in the Hinkley Nuclear Power Station decision letter (see paragraph 6.4.9(v)) which endorse that it may be justifiable (and practical) to allow compulsory acquisition where maintenance is required over a long but non-permanent period.

Finally, it’s interesting to note the government’s impact analysis of BNG applying to NSIPs – in particular, their estimate of costs for the implementation of BNG:

  • Familiarisation costs (transition) – There will also be a one-off familiarisation cost to NSIP developers. Due to the small number of firms developing NSIPs, this is expected to be a relatively low cost of approx. £19,000.
  • Cost of delivering biodiversity units (developers) (Ongoing) – Developers will face a cost of delivering bio-diversity units to offset the loss created by their developments plus an additional 10%. Annual average £14 million (£3 million – £33 million).

I’m sure we all have no comments on these estimates.

The consultation closes on 5 April 2022 (probably – the consultation document says 4 April) – though this is not the end of the road for DCO projects given the consultation document confirms that the ‘Government will consult again on the full draft approach (biodiversity gain statements) for Nationally Significant Infrastructure Projects’.

Related Articles