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Biodiversity Net Gain Assessment for Developments

As it is now a part of UK legislation, Biodiversity net gain will become a mandatory point for all upcoming development projects in England. Biodiversity net gain 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 can be done by avoiding biodiversity loss, retaining various habitat types and protecting any assets of strategic significance.

Biodiversity Net Gain (BNG) assessments are being requested more frequently by Local planning authorities to inform a planning application. The aim is to demonstrate how the proposed development will be of benefit to biodiversity in a measurable manner. BNG also acts as a planning condition as well as a policy requirement for planning consent. It can therefore have a significant impact during the decision making process of planning authorities when they debate whether to grant or refuse a planning application.

what is biodiversity net gain

Biodiversity Net Gain Assessment


Biodiversity on a development site can be accurately measured using the biodiversity metric 3.0 calculation tool. This tool can help to determine your biodiversity unit score and translate it into the standards of your local planning authority. In order to calculate Biodiversity Net Gain credits, this tool requires a range of information.

This includes data such as habitat areas, habitat types and habitat conditions in order to create a measure of biodiversity for any development site. This tool then calculates a required percentage gain for the site. This calculation will also help to determine whether the site meets the BNG requirements.

This calculation will take into account the habitats on site prior to the development, as well as the available habitats presented in the development plans. An assessment of the habitats on site must be identified by an ecologist by using a site survey. This site survey should include case studies on the existing biodiversity interests and possible impacts on them.  It should also provide details of any measures proposed to compensate or mitigate for any impacts caused on the surrounding environment using a mitigation hierarchy.


Why are Biodiversity Net Gain Assessments required?


The Environment Bill was passed in 2021. Under The Environment act 2021, developments and projects will now need to ensure there is at least a 10% net gain to biodiversity. This net gain will be measured through Metric 3.0.  

Biodiversity net gain will soon become mandatory due to The Environment Act that will be introduced in 2023. This act will introduce the requirement to deliver biodiversity net gain for all developments in England. The current national policy in England, The National Planning Policy Framework (NPPF) Paragraph 179 states:

“To protect and enhance biodiversity and geodiversity, plans should:

  1. b) … identify and pursue opportunities for securing measurable net gains for biodiversity.”


As a result of this, many planning applications for developments will now be unable to proceed until local planning authorities are satisfied that the required biodiversity standards have been met. Therefore, providing Biodiversity Net Gain assessments alongside methods for achieving Biodiversity Net Gain within a development’s proposal will soon become essential in order to receive the appropriate planning permission.


How can Collington Winter assist with Biodiversity Net Gain Assessments?


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 net gain report for BNG assessments.

Our team of ecologists and landscape architects have helped numerous clients over the years. This includes matters regarding policy guidance for biodiversity gain in England. It is important to note that this varies across each Local Authority in the country.

Biodiversity is something that we are qualified and experienced in, and we can offer advice on your development project. We are determined to offer you the support you need both pre and post development in order to reach the required mandatory biodiversity net gain bracket.

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

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