Biodiversity net gain and the Environment Act 2021

In the first in a series of articles, Amy Truman and Henry Jeffreys examine the elements of the Environment Act 2021 which secure the provision of biodiversity net gain.

The Environment Act 2021 (“Act”) contains provisions for the protection and improvement of the environment, including introducing biodiversity net gain (“BNG”). Whilst the provisions are not yet in force, they may already have implications for the viability of development proposals.

This article provides an overview of how BNG requirements are currently envisaged to apply to development under the Town and Country Planning Act 1990 (“1990 Act”) and applications in respect of nationally significant infrastructure projects (“NSIPs”) under the Planning Act 2008 (“2008 Act”).

1990 Act development

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Deemed Planning Condition

The concept of BNG will already be familiar, due to the existing policy requirement in the National Planning Policy Framework. However, the Act elevates the requirement to a statutory footing. This is achieved by the imposition of a deemed planning condition in England, subject to limited exceptions in relation to permitted development granted permission by development order and urgent crown development (the Government’s current consultation on BNG regulations and implementation proposes further exemptions).

The deemed condition will prevent commencement of the planning permission until a BNG plan has been approved by the local planning authority. The BNG plan must set out how the “Biodiversity Gain objective” is met.

Biodiversity Gain objective and the Biodiversity Metric

The Biodiversity Gain objective requires the biodiversity value attributable to a development to exceed pre-development biodiversity value by at least 10% (this percentage may be changed by regulations, although nothing is currently proposed).  Post-development biodiversity value may comprise onsite habitat, offsite biodiversity gain and biodiversity credits, although the present consultation suggests that biodiversity credits will be a method of last resort.

Ordinarily, the pre-development biodiversity value of a site is calculated with reference to the on-site habitat at the date of the planning application. However, for 1990 Act development proposals, if any activity on the site after 30 January 2020 degrades the on-site biodiversity, and was not authorised by a planning permission, the pre-development biodiversity value will be the value existing immediately before those activities were carried out.

Biodiversity value will be calculated in accordance with a biodiversity metric (measured in terms of “biodiversity units”). The metric currently developed for these purposes is the Biodiversity Metric 3.0, issued by Natural England in July 2021.

Securing post development BNG

Any off-site BNG units must be secured through a conservation covenant or planning obligation, and be maintained for at least 30 years. The consultation envisages that off-site works should be commenced as soon as possible, and not more than 12 months after discharge of the BNG condition. It remains to be seen how this will operate, for example where implementation of the development is not required in this timescale.

2008 Act development

Amendments to the 2008 Act provide that the Secretary of State may not grant an application for a development consent order (“DCO”) for NSIP development where a “Biodiversity Gain statement” applies unless satisfied that the Biodiversity Gain objective is met. While the nature of the Biodiversity Gain objective is similar to that for 1990 Act development, the Biodiversity Gain statement is unique to the BNG requirements for NSIPs.

Biodiversity Gain Statement

A new Schedule to the 2008 Act provides that, on the first review of a National Policy Statement (“NPS”), the government must include a biodiversity gain statement. Where a category of development does not have an associated NPS, or the relevant NPS does not yet provide for BNG, the government may (subject to consultation) issue a separate Biodiversity Gain statement. The Biodiversity Gain statement sets out the biodiversity gain objective and requires that this is met by applications in England. Once issued, applications must be determined in accordance with the Biodiversity Gain statement.

In addition, Biodiversity Gain statements may specify requirements to be included in a DCO to counter any adverse impacts on onsite habitat, or the evidence required in a DCO application to demonstrate that the Biodiversity Gain objective has been met.

The Biodiversity Gain statement will set out the biodiversity value calculation, by reference to a biodiversity metric to be published by the government. As for 1990 Act development, it is expected that the Biodiversity Metric 3.0, will fulfil this role subject to any necessary amendments to account for its application to NSIPs.

What next?

The ongoing consultation suggests that the provisions in relation to 1990 Act development should be in force by November 2023, while the BNG requirement should apply across all terrestrial NSIPs, or terrestrial components of NSIPs, accepted for examination by the Planning Inspectorate by November 2025. 

Whilst not yet in force, these provisions warrant consideration ahead of time to ensure that any impacts on viability caused by BNG requirements can be accommodated within future development proposals. Even where the Act is not in force, local planning authorities and examining authorities are likely to want to consider the position on biodiversity net gain.

Amy Truman is a Senior Associate and Henry Jeffreys is an Associate Solicitor at DLA Piper.

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