Biodiversity Net Gain
Biodiversity Net Gain is now Mandatory for Most Planning Applications in England
EPR is at the forefront of Biodiversity Net Gain practice, having published three reports on the subject to support developers and landowners
BNG in development is defined as “development that leaves biodiversity in a better state than before”
The Environment Act, which gained Royal Assent in November 2021, mandates that 10% BNG is a legal requirement of planning consent for most types of planning application in England. This was implemented through amendments to the Town and Country Planning Act 1990, which came into force on 12 February 2024 (and is due to come into force in April 2024 for small sites and in 2025 for Nationally Significant Infrastructure Projects).
To help you navigate the changes, we’ve prepared a document setting out responses to the Biodiversity Net Gain questions we are most frequently asked. The document is available as a download below.
EPR has been at the forefront of Biodiversity Net Gain from its original inception.
The timeline of our BNG experience, available below, sets out our involvement in policy development, our communications on the topic and selected project initiatives. We have published three reports on the subject to support developers and landowners which are also available for download further down the page.
Biodiversity Net Gain Assessment
A Biodiversity Net Gain Assessment compares existing habitats with proposed post-development habitats and uses a metric to compare the two. A net gain is achieved if the post-development habitats result in an improvement when compared to the baseline.
We have completed many Biodiversity Net Gain Assessments for clients across a variety of sites and scenarios. This experience has given us a detailed understanding of the statutory DEFRA BNG metric, its intricacies, and how it works.
For developers, we use that understanding to provide specialist advice from the masterplanning stage to detailed landscape design to maximise the biodiversity gains that are delivered by a project. We help you meet policy requirements to secure a planning consent, so that the spaces created are sustainable and leave a legacy you can be proud of.
If you are a landowner, we can advise on how you might be able to deliver biodiversity units on your land that could be sold to third parties who are unable to meet their BNG obligations on-site. This could form part of a feasibility study that compares the income potential of BNG with other land-uses.
We can also help Local Planning Authorities to review metrics and supporting information submitted by planning applicants, and provide training on BNG and its nuances.
A Biodiversity Net Gain Assessment broadly involves:
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A survey of your site to map the pre-development habitats and record their condition. We enter the data into the statutory version of the BNG metric to generate a baseline score.
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We use landscape plans and habitat creation/management plans to generate a list of post-development habitats, areas, and target conditions. We enter this data into the statutory metric to generate a post-development score.
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The Biodiversity Net Gain or loss, expressed as a %, is calculated by comparing the baseline and post-development scores. We then check that this meets certain criteria embedded into the statutory metric, such as those relating to ‘trading rules’ and ‘additionality’.
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We provide specialist advice to refine the post-development landscape proposals or reposition the developable space and maximise Biodiversity Net Gain.
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Off-site gains can be added, if required, to increase the post-development score. We can negotiate with third parties on your behalf or look at additional land within your/your client’s ownership.
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If applicable, we can also advise on how any surplus biodiversity units might be ‘banked’ for other schemes/future development phases.
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We also use our experience to effectively explain to the LPA and other consultees how Biodiversity Net Gain will be delivered.
Biodiversity Net Gain Assessments for habitat creation schemes follow a similar process, modelling different scenarios and outcomes. We would also look at factors such as the local demand and market prices for different habitat unit types, and the potential to ‘stack’ BNG units with other environmental payments such as nutrient mitigation.
Please click below for our BNG case studies on the Hampton Estate and Nansledan.
EPR has prepared a short report outlining what the Environment Act means for development and wildlife in the UK. You can download the report by clicking on the link below.
Biodiversity Net Gain is also enshrined in the National Planning Policy Framework and many Local Planning Authorities also have Biodiversity Net Gain related planning policies.
River Condition Assessments
EPR has several in-house ecologists accredited to complete River Condition Assessments, used where rivers and streams must be considered as part of a BNG calculation using the Statutory DEFRA BNG Metric.
The condition of rivers and streams within the statutory Metric is calculated by completing a River Condition Assessment, which involves:
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A largely desk-based assessment to identify the current river type.
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A field survey to record channel dimensions, physical features, habitats, vegetation, and human interventions.
Data from these elements is entered into specialist online software to determine river condition, which is interpreted by our accredited ecologists and entered into the statutory metric.
Our accredited ecologists can also model the impact of post-development interventions and provide advice on maximising river and stream related biodiversity gains.
“We regularly work with EPR, who always demonstrate up to date knowledge and intelligence on ecological matters. They are particularly strong on Biodiversity Net Gain, and their approach to HRA matters – and provide excellent written reports. In addition, they have a strength with Examinations and Public Inquiries. And on top of that, they are great to work with!”
Charlie Collins, Head of South East Planning, Savills
“It is really refreshing to see the metric properly populated with justification for each condition and habitat in the comments section. It is amongst the best I have seen in this regard. The management regimes also match the post development habitat condition assessments.”
Matt Dodds, Planning and Biodiversity Manager Herts Wildlife Trust
Building for Biodiversity Reports
We’ve published two reports to help guide developers and landowners through the BNG process.
“The full Biodiversity Metric has been provided for assessment and Appendix 1 of the Ecology Addendum provides an explanation of the calculations and the assumptions that have been made. EPR should be commended for manually recalculating biodiversity net gain (BNG) to ensure that measures required as mitigation for impacts on protected species and the LWS are not counted towards BNG. The assumptions are based on sound professional judgement and I agree that they make sense ecologically, taking into account the constraints of the Metric, and taking a precautionary approach.”
LPA ecologist
