Collington Winter Environmental

Biodiversity Net Gain Legislation and Requirements

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In November 2021, The Environment Act received royal assent following the passing of The Environment Bill. This act was described as a ‘turning point for nature’ by Natural England. A key part of this environmental legislation was the introduction of biodiversity net gain (BNG).

Biodiversity Net Gain is an approach to development that aims to leave the environment in a better state than it was before the development project took place. Previously, planning policy has encouraged UK construction and developments to achieve “no net loss” for biodiversity.

However, over the years, biodiversity has declined in the UK, and as such, the BNG initiative was launched to leave nature in a measurably better state. Overall, there has been a positive response to the consultation from ecological consultants, developers, and landscape professionals.

Through biodiversity net gain legislation, mandatory BNG for developments in England will be introduced in 2023. Local planning authorities are beginning to request BNG more frequently and are using it to inform planning applications for planning permission.

What Biodiversity Net Gain Legislation Will Introduce

The Environment Act 2021 has addressed issues on several areas, including clean air, waste, recycling, water and nature. Whilst the act is in depth and covers 8 different sections, there are key environmental targets to the legislation. These include the following:


  • Halt the decline of nature and habitats by 2030
  • Embedding environmental principles into domestic policymaking
  • Environmental monitoring and reporting
  • The creation of the Office for Environmental protection
  • Requiring local authorities to prevent local air quality issues
  • Tackling waste crime
  • Increase focus on biodiversity net gain and ensure that new developments deliver a 10% increase in the biodiversity surrounding it
  • Minimising damage water abstraction
  • Strengthen the protection of woodland areas
  • Increase on site habitat enhancement


Mandatory biodiversity net gain and other items mentioned in The Environment Act 2021 and other biodiversity net gain legislation will soon become legally binding in 2023. Therefore, it is essential that developers understand biodiversity net gain requirements and how biodiversity net gain will work in practice.

What Biodiversity Net Gain Legislation Will Mean For Developments

The main aim of biodiversity net gain legislation is to create an economy that has the environment at its focus. Biodiversity net gain is not a new concept, and the National Planning Framework requires a net gain approach, there has never been a statutory requirement for BNG until this point.

Under The Environment Act 2021 and other biodiversity net gain legislation, development projects and nationally significant infrastructure projects will now be required to ensure that there is a 10% net gain to biodiversity at a minimum on site. These net gains will be measured through Biodiversity Metric 4.0.

Developers will now be required to show how biodiversity net gain will be achieved in pre development biodiversity plans. For these plans to be considered valid, BNG must be guaranteed for at least 30 years.

Mitigation hierarchies must also be followed and demonstrated to minimise, avoid or compensate for any biodiversity losses. It is not possible to avoid or compensate on site, offsetting will be required in post development through conservation covenants or by purchasing biodiversity credits.

What is required from developers under The Environment Act 2021?

Developers who are planning a development project in England must now understand how The Environment Act 2021 will change each aspect of development. The legislation aims to make developers consider net gains for biodiversity from the land acquisition stage through to the design stage, ensuring long lasting positive effects.

Developers will primarily see a change in the planning stages, and local planning authorities will be expected to create new nature recovery strategies to meet the standards included with The Environment Act 2021.

Also, under the act, developers must create a pre development biodiversity net gain plan in order to show how their project will achieve the biodiversity net gain requirements. Planning permission in England will only be granted upon completion of this plan. Therefore, it is essential that you seek assistance from a biodiversity net gain consultant in order to create a detailed plan to have planning permissions granted.

What Developers Must Do Under Biodiversity Net Gain Legislation

Developers who are planning a development project in England must now understand that The Environment Act 2021 and further biodiversity net gain legislation is changing every aspect of development. Biodiversity net gain legislation aims to make developers consider on site biodiversity from the planning process and land acquisition stage to the design stage. It is intended for biodiversity gains to be implemented into the designs rather than introduced retrospectively.

Under the Environment Act 2021 and amendments to the Town and Country Planning Act of 1990, planning permission in England will only be granted with a BNG plan. Therefore, it is essential to seek the guidance of a biodiversity net gain consultant during the early stages of development. BNG consultants can create and develop BNG plans in order to meet biodiversity planning requirements for local planning authorities and achieve planning permission.

How can we assist with biodiversity net gain?


Our team of biodiversity net gain consultants have helped a number of developers over the years. We have provided policy guidance for biodiversity net gain in England. We can complete an initial assessment for development sites to help our clients understand the probable implications and costings of BNG from the outset.

Please get in touch if you would like further information on biodiversity net gain legislation or a consultation on biodiversity net gain. If you would like to find out more about the services we provide, feel free to contact us using the contact details below.

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23 Bark Street East, 1st Floor, Bolton



01204 939 608


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