The Environment Act 2021 received Royal Assent in November 2021 and introduced a framework whereby planning applications in England must secure a 10% post development biodiversity net gain compared to the pre-development biodiversity of the site. It will be mandatory for planning applications to include a planning condition to secure compliance with this requirement. The Government is currently consulting on the secondary legislation needed to bring biodiversity net gain into force.
Who will be affected?
The Government consultation paper indicates that virtually all planning permissions granted under the Town and Country Planning Act 1990 will be subject to this condition, subject to only a few specific and limited exemptions, namely development permitted by a general permitted development order, and urgent Crown development.
The proposals
The Environment Act 2021 provides that planning will be granted subject to a pre-commencement condition that development cannot begin until the developer has submitted a biodiversity gain plan demonstrating that the biodiversity value attributable to the development exceeds the pre-development biodiversity of the onsite habitat by at least 10% - this is referred to as the biodiversity gain objective.
The biodiversity gain plan will need to: calculate pre and post-development biodiversity value of the onsite habitat; set out steps to minimise adverse effects on the biodiversity on the onsite habitat; and detail proposed mitigation if 10% net gain cannot be achieved onsite. Further details relating to the content of these plans, together with procedures for submission, determination and appeal will be set out in forthcoming regulations.
The local planning authority must be satisfied that the biodiversity gain plan contains the required information and that the biodiversity gain objective is achieved. If a biodiversity gain plan is refused, the development cannot proceed lawfully.
Calculating biodiversity value
Biodiversity value will be determined through calculating the pre- and post-development values. Conceptually it will be calculated by applying the 'biodiversity metric', developed and published by the Secretary of State. The metric is already in use by ecologists where many local planning authorities have biodiversity net gain policies already in force.
Achieving the biodiversity gain objective
If the developer seeks to achieve the objective through measures onsite then those measures will need to be secured through a condition or a planning obligation, and that mechanism must be maintained for at least 30 years after the completion of development.
If onsite improvements cannot be achieved, the Act provides a means of compensating for the deficit through one of two ways:
- buying biodiversity benefits achieved on 'Biodiversity Gain Sites'; or
- purchasing biodiversity credit from the Government.
These mechanisms are designed to cater for situations where it is not feasible to achieve the biodiversity gain objective on site, so you can have allocated to the development, registered offsite biodiversity gain. The details on which sites are available to provide this compensatory benefit will be published in a new Biodiversity Gain Site Register.
Viability
Achieving a 10% biodiversity net gain will potentially add significantly to the cost of development. The Government has not been explicit on how biodiversity net gain will interact with viability constraints and the burden of other planning obligations and conditions. The latest consultation material indicates that the Government is not considering a "viability" exemption from the requirements and as such this may lead to other items of infrastructure or affordable housing provision being sacrificed.
What happens next?
The Government is consulting on the secondary legislation, and a link can be found at:
The Government has indicated that biodiversity net gain will become a legal requirement by November 2023 at the latest.
Trowers & Hamlins biodiversity team will continue to monitor the progress of the secondary legislation and we aim to provide regular updates on how it is implemented in practice and considerations for developers and local planning authorities that might result.
Trowers & Hamlins biodiversity team will continue to monitor the progress of the secondary legislation and we aim to provide regular updates on how it is implemented in practice and considerations for developers and local planning authorities that might result.
If you would like to learn more about biodiversity net gain, please view our recorded seminar on the topic where we offer our legal view alongside ecologist Jon Garner of BioGains:
Updated March 2022
