BNG Trading Rules Explained: A Developer’s Guide
Understanding the BNG trading rules is essential for developers to avoid delays, added costs, and rejected Biodiversity Gain Plans.
Biodiversity Net Gain (BNG) is now a mandatory part of the planning process and the trading rules are one of the most common stumbling blocks for developers. Even if you’ve achieved the required 10% net gain, your Biodiversity Gain Plan could still be rejected if the trading rules aren’t satisfied.
In this blog, we’ll explain:
What the trading rules are and why they matter
The key “like for like” and “like for better” principles
Practical mistakes to avoid
How ILM helps developers stay compliant
Why do BNG Trading Rules Matter?
The trading rules form part of the Statutory Biodiversity Metric. They’re designed to make sure habitats lost to developments are replaced with habitats of equal or greater value.
For developers, missing this step can mean:
Planning application delays
Higher costs from sourcing units at the last minute
Lack of availability in your target location
Reputational risk with planning authorities
Related reading: BNG Trading Rules for Developers Pt. 1
What are the BNG trading rules?
At their core, the rules require you to replace lost habitats on a like-for-like or like-for-better basis within the same habitat module. You can’t swap across modules - for examples, hedgerows can’t be replaced with grassland - find everything you need in our free guide. Download it here.
The three habitat modules:
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Grassland, woodland, heathland, arable margins.
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All linear hedgerows
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Rivers, streams, ditches, canals.
Preview from our free Developer’s Guide to BNG Trading Rules. Download the full guide for worked examples and your quick-reference checklist.
Distinctiveness Levels:
Very High - High - Medium - Low - Very Low
Definitions:
Like-for-like: replace with the same habitat type (or in some cases, another of the same broad group at the same distinctiveness level).
Like-for-better: replace with a higher distinctiveness habitat within the same module.
Related reading: BNG Trading Rules - Rule 4
Applying the trading rules (step by step)
To comply, developers typically follow six steps:
Run a baseline ecological survey
Use the Statutory Biodiversity Metric to calculate losses
Identify replacement requirements per module and distinctiveness levels
Plan unit procurement early (on-site if possible, off-site or a combination of both if not)
Apply location multipliers to get the most value
Validate compliance with the metric’s ‘Trading Summary’ tab
Don’t let the trading rules disrupt your project. Download the Developer’s Guide to BNG Trading Rules.
