
Insight
Biodiversity Net Gain (or BNG) is a principle which aims to leave the natural environment in a measurably better state after development than beforehand. The requirements set down by law will apply to all sites (save for exempt sites) from November 2023.
Following a consultation in December 2018 which first considered BNG proposals, the government con-firmed its intention to bring in new law which would require new developments to deliver a net increase in biodiversity of at least 10%. In November 2021, the Environment Act 2021 received Royal Assent and so it was that the requirement entered the statute books and became mandatory.
A series of further consultations and responses ensued, discussing the practicalities of implementing the scheme and its scope, with the result that as of November this year, Defra’s new biodiversity metric version 4.0 will form the basis of calculating BNG.
Biodiversity gain objective
The new statutory provisions introduce the concept of a ‘biodiversity gain objective’. This is met if the “bio-diversity value attributable to the development” exceeds the pre-development biodiversity value of the on-site habitat by at least 10%.
The “biodiversity value attributable to the development” is the total of:
(1) the post-development biodiversity value of the onsite habitat
(2) the biodiversity value of the development of any registered offsite biodiversity gain allocated to the development (see ‘Offsite biodiversity gain’ below)
(3) the biodiversity value of any biodiversity credits purchased for the development (see ‘Offsite biodiversity gain’ below).
Planning condition to submit a Biodiversity Gain Plan
The outcome of the legislative changes is that every planning permission granted for the development of land in England (including deemed planning permission) that results in a loss or degradation of habitats, will have a mandatory condition imposed (or deemed to be imposed) to secure the 10% BNG.
BNG will not apply to:
BNG will, however, apply to:
Where irreplaceable habitats are impacted by development, new Regulations will require measures to be taken to minimise the adverse impacts of the development on those habitats.
The Government has confirmed that there will be a transition period until April 2024 for small sites to provide BNG. Until then, small sites will be exempt from having to provide on- or off-site BNG.
Small sites are defined for the purpose of the BNG exemption as:
We may also see regulations to modify the application of BNG in relation to:
The biodiversity value of any habitat is to be calculated in accordance with the biodiversity metric, which is to be produced and published by the Secretary of State (Defra). The provisions allow for the metric to be updated to allow for technical improvements.
The Government has confirmed that the next version of the biodiversity metric, metric 4.0, will be published by November 2023 and will form the basis of the statutory metric for the purposes of statutory BNG.
Importantly, where activity is carried out on land on or after 30 January 2020, without planning permission, which causes the onsite biodiversity value to be lowered, that activity is not taken into account when calculating the site’s pre-development biodiversity value.
The post-development biodiversity value is the projected value of the onsite habitat as at the time the development is completed. Proposals for BNG works can only be considered as part of the post-development biodiversity value if the gain will be maintained for at least 30 years after completion of the development, and secured by either a condition, a s106 or a Conservation Covenant.
Offsite biodiversity gains can be registered and biodiversity credits are to become available, which can be taken into account in deciding whether a development meets the biodiversity gain objective.
Registered offsite biodiversity gain is essentially biodiversity gain achieved on land other than the development site, which is subject to an arrangement so that it can be counted towards the development meeting the biodiversity gain objective.
Natural England will be setting up a Biodiversity Site Gain Register (hopefully very soon!), which will be a register of parcels land:
Landowners will be able to register their parcels of land with the Register, details of which will be publicly available and open to bids to obtain credits on.
Probably the most controversial element of the proposals: biodiversity credits can be bought and sold in connection with development, so that development can meet the biodiversity gain objective.
The price will be set by the Secretary of State but there is much scepticism over the Register being used to simply ‘buy’ planning permissions. It is speculated that the cost of the credits will be prohibitively high in an attempt to prevent this from happening and to enable a real impact to result from the credits purchased.
Payments received for the credits can be used to fund biodiversity enhancements, including to purchase land to do so, and the Secretary of State must report annually on their use.
In terms of how BNG can be achieved, the PPG advises that:
The Government’s most recently closed consultation package looked further into measures to ensure that BNG can deliver, and wider opportunities to support BNG and biodiversity generally.
Whilst much has been progressed over the last couple of years, it is clear that there is a lot of detail still remaining and further consultations have been proposed on a variety of issues, including further secondary legislation and revisions to the NPPF.
If the Government (and everyone else involved) is to secure BNG in the way in which it envisages, starting in November this year, there are many strings to pull together in order to make it happen, including landowners, local authorities, ecologists, developers, lawyers, committee members and inspectors. Everyone will need to act quickly in reaction to revised guidance issued by Defra and be prepared to fully update those who rely on their advice.
For further information, please contact our Planning Team.