LNRSs and strategic significance: what’s changed and how to get it right

Whether you're preparing a Biodiversity Net Gain (BNG) assessment or reviewing one, the rules around strategic significance in areas covered by an adopted Local Nature Recovery Strategy (LNRS) have changed. This short article explains what the rule changes are, what they mean for you, and how we've updated Mycelia to catch them automatically.

What the updated rules require

Under the updated Statutory Biodiversity Net Gain Metric Guidance, two rules now apply where an LNRS has been adopted:

• Baseline habitats should default to "low" strategic significance unless there is a specific, justified reason to set them higher.
• "Medium" strategic significance is no longer permitted for post-intervention habitats. In LNRS areas, post-intervention habitats must be either "high" (aligning with LNRS priorities) or "low" (not aligning). The middle ground has been removed.

The practical consequence is straightforward but easy to miss: a habitat incorrectly set to "medium" instead of "low" will inflate the baseline value. Multiply that across several parcels and the metric calculation will contain compound errors leading to reworked submissions and delayed decisions.

These changes reflect what LNRSs are designed to do: coordinate nature recovery priorities at landscape scale and direct BNG investment toward the places where it will do the most ecological good. Getting strategic significance right is how that direction is enforced in practice.

How Mycelia flags LNRS strategic significance issues

We've made updates to Mycelia's Ecology Risk checks that target these specific requirements. Mycelia will now warn you if a metric has not used "low" strategic significance for a baseline habitat, or has used "medium" for a post-intervention habitat, so that you can check any relevant LNRS.

These two checks are part of a broader set of Ecology Risk updates now live in Mycelia, covering mapping and data integrity, survey evidence quality, and habitat target realism. The full list is on our Ecology Risks support page.

All Mycelia's Ecology Risk checks run automatically when you upload a metric.

Clarity on LNRS strategic significance for the future

As more areas adopt their LNRS, these new strategic significance requirements will become the norm rather than the exception. If you have questions about how any of this applies to your projects or review process:

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