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Biodiversity Net Gain 2024: Guidance on new rules

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In 2024, Biodiversity Net Gain (BNG) emerges as a leading force in the United Kingdom’s efforts toward environmental conservation and sustainable development. BNG represents an innovative approach requiring developers to leave the natural environment in a measurably better state than before their projects commenced.

As a result of the Environment Act 2021, Biodiversity Net Gain is set to become a mandatory practice for all development proposals in the UK. Developers must adhere to BNG principles and ensure their projects meet its criteria. Additionally, developers will have to guarantee that BNG is secured for at least 30 years.

In January 2024, the UK government released additional guidance on BNG ahead of its implementation. Furthermore, BNG’s official implementation date is confirmed for February 12, 2024.

What types of development will BNG apply to?


From 12 February 2024, BNG will be mandatory for new planning applications for major development made under the Town and Country Planning Act 1990. Major developments include residential developments with 10 or more dwellings or if the site area is greater than 0.5 hectares.

Biodiversity net gain will be made mandatory for small sites from April 2024. Small sites include residential developments where the number of dwellings is between 1 or 9 or if the site area is less than 0.5 hectares. Small sites also include commercial developments where floor space created is less than 1000 square metres or the overall site area is less than 1 hectare.


Updates to BNG related legislation

In November, a draft of the secondary legislation package was released to assist stakeholders in readiness for mandatory BNG. Following this, some slight modifications were made to the legislation’s wording. Notably, there has been considerable focus on the de-minimis exemption and the biodiversity gain hierarchy. Based on conversations with stakeholders, clarifications and modifications have been introduced.

Why is BNG being required by local planning authorities?

BNG is significant for a variety of reasons and can help to positively affect the surrounding environment and wildlife. Some of the main benefits that BNG provides include:

  • It supplies oxygen and water to the surrounding environment
  • Enhances the visual appearance of the environment
  • Facilitates a scientific understanding of the environment
  • Provides jobs for agricultural occupations
  • Helps to protect special scientific interest sites, nationally significant infrastructure projects, and irreplaceable existing habitats

The concept of mandatory biodiversity net gain planning condition is a structured method of ensuring that all of the factors listed above are encouraged and supported in the years ahead.

As BNG applies to all planning projects, it causes a universal approach from governing bodies and local authorities. Therefore, due to the fact that BNG is a government policy, it prevents any potential issues with key stakeholders.


Implementing BNG

If you are uncertain about the potential impact of mandatory biodiversity net gain on your planning application, it is advisable to reach out to your local planning authorities as soon as possible. They can provide detailed insights into your development plans and assess their alignment with BNG requirements and planning obligations.

Should your authorities suggest that your development might face significant implications, we advise seeking assistance from a knowledgeable ecologist. Our ecologists can evaluate whether your plans meet the necessary standards and suggest any measures you may need to implement to adhere to biodiversity requirements.

Our team has strong experience completing BNG and will provide guidance throughout the planning process. We can ensure that one of our experienced biodiversity ecologists visits your development site to create and develop any required BNG reports using biodiversity metrics. Our team can also assist with habitat enhancements by using a Natural England habitat management and monitoring plan template.

Biodiversity net gain plans

In order to obtain planning permission for a project from a local planning authority, developers must be able to prove that they are taking the correct measures to increase BNG. One of the first steps in this process is to book an experienced ecologist to create a biodiversity gain plan.

Depending on the ecologist’s findings within a biodiversity net gain assessment, the BNG plan will help to determine natural elements that could potentially be at risk as a result of the development project. The plan will also detail any mitigation methods, such as conservation covenants or habitat recreation, to be taken in order to prevent these outcomes from occurring both on site and off site.

The aim is to get clients to think about biodiversity during the initial planning and design stages and avoid retrofitting once designs have been produced. Retrofitting will often lead to delays, unpredicted financial costs and difficulties with planning application determinations.


How can we assist?

Our team of ecologists and land managers have helped numerous clients over the years, including policy guidance for delivering Biodiversity Net Gain 2024. 

We can assist with biodiversity net gain by providing: 

Please get in touch if you would like further information about further biodiversity net gain 2024 guidance. We are happy to offer free CPD sessions on the BNG principles and how we can help your schemes achieve this.

Our Ecology Director, Olivia Collington, holds a Natural England license. If you would like to find out more about the services we provide, feel free to contact us using the details below.

Registered Office

23 Bark Street East, 1st Floor, Bolton



01204 939 608


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