Biodiversity Net Gain 2023: What developers need to know

Biodiversity net gain (BNG) will soon become a mandatory point for all upcoming development projects in England. BNG refers to the process whereby a development (or project) considers the environmental impact in terms of biodiversity. It aims to ensure that biodiversity is left in a better state than before the development was completed. This is done by avoiding biodiversity loss, retaining various habitat types and protecting any assets of strategic significance.

Biodiversity net gain will apply from November 2023 for all projects in the Town and Country Planning Act 1990 unless they are exempt. It will then apply to small sites in April 2024.

Biodiversity net gain 2023 will affect developers as planning applications to obtain planning permission from local planning authorities may be rejected if the proposals do not reach the required BNG standards. Biodiversity net gain is already being requested for some nationally significant infrastructure projects in the UK.

According to the Chartered Institute of Ecology and Environmental Management (CIEEM), there are ten crucial good practice principles of biodiversity net gain. These should help to achieve BNG if they are followed accordingly. The mandatory BNG principles include the following:

• Utilise the mitigation hierarchy to minimise the impact on biodiversity
• Eliminate any negative impacts on biodiversity
• Communicate each BNG outcome with complete transparency
• Cover all areas of sustainability, including societal and economic factors
• Involve any pre-development and post-development stakeholders in creating mandatory net gain solutions
• Focus on producing long-term environmental benefits from BNG
• Understand the variable factors and potential risks in order to achieve biodiversity and deliver biodiversity net gain
• Offer nature conservation that exceeds the stated BNG requirements
• Determine a suitable method in order to secure measurable biodiversity net gains
• Ensure the best possible results from biodiversity net gain

For case studies and a practical guide on BNG principles, visit the CIEEM website.

Our team has strong experience completing BNG and will provide guidance throughout the planning system process. This applies from the initial land purchase agreements to monitoring assessments. 

The Environment Bill was passed in 2021, and BNG will soon become legally binding through the forthcoming Environment Act in 2023. On the 21^{st of} February 2023, the Government published its long-awaited response to its mandatory BNG consultation in January 2022. BNG is expected to become mandatory for all developments in January 2024.

Within The Environment Act it aims to include a range of environmental improvements. These include the following:

• Improve the development of effective conservation covenants
• Increase the use of recycling
• Improve water and air quality
• Recall products that violate environmental standards
• Protect local wildlife species
• Regulate chemicals that may harm the environment
• Reduce plastic waste
• Reduce biodiversity loss

As a result of this Bill, BNG has been served as a core policy with numerous long term effects on ensuring the preservation of habitat types for a minimum of three decades. The act’s purpose is to address the issues of climate change and the loss of biodiversity by taking protective and proactive steps. The act will help to ensure that developers and land managers leave the natural environment in a better state than it was previous to a project’s completion.

Developers must now be able to show that their project will result in a measurable increase in biodiversity and should be maintained for at least 30 years. If they fail to do so, they may be unable to obtain planning permission from local planning authorities.

This percentage increase will be the total of:

• The biodiversity within the red line boundary following development compared to the level prior to development
• Biodiversity gains off the site that is registered against the development
• Biodiversity credits bought for the development from the government

In certain cases, a local planning authority may ask for a higher percentage than 10%. New local nature recovery strategies (LNRS) will be prepared to geographically cover England by responsible authorities; this will encourage habitat creation and enhancement in the right places. Biodiversity should be achieved on site where possible, although there may be opportunities for offsite BNG offsetting where necessary.

Metrics assign every habitat on a site a ‘biodiversity unit value’ according to its relative importance for biodiversity. This enables comparison between the existing value of a site and what will be delivered through development or management and post development. This may include an increase in natural habitats through retention and enhancement and/or creation, which goes over and above the environmental habitat originally on site.

BNG can be calculated through the DEFRA biodiversity metric 3.1, which requires a limited number of factors. These factors include:

• The type of habitat (both on and off site)

• Any locations (if they are local environment priorities)
• The size of habitat parcels in kilometres or hectares
• The condition of any habitat parcels

The government website also provides a biodiversity metric 3.1 calculation tool which can help to determine your biodiversity unit score. This will then translate into the standards of your local planning authority.

If you are unsure of how mandatory biodiversity net gain 2023 requirements may affect your planning application, you should contact your local planning authority immediately. They can discuss your development plans in detail and whether they align with BNG.

If they indicate that your development could be significantly impacted, we recommend that you contact an experienced ecologist as soon as possible. Our ecologists can discuss whether your development plans meet the required standards. They can also recommend any measures you may need to take in order to meet the biodiversity standards.

At Collington Winter, 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 necessary BNG planning statements and any required BNG reports.

Our ecologists will complete a habitat classification assessment, and the data is entered into a metric to measure changes to the natural environment, pre and post development. This metric is currently Defra Metric 3.1. Landscape planting plans and management plans are used to inform post development measures.

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

Depending on the ecologist’s findings within a BNG assessment, the BNG plan will help to determine natural elements that could potentially be at risk as a result of the development project and any mitigation methods to prevent these outcomes from occurring. These methods will be identified alongside the mitigation hierarchy to ensure that the development has the best chance of being approved.

Our team of ecologists and land managers have helped numerous clients over the years, including policy guidance for biodiversity net gain 2023 in England.

We can assist with biodiversity net gain by providing: 

• BNG guidance
• Assessments
• Mitigation

Please get in touch if you would like further information about how to deliver BNG. We can also develop land management plans. 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.