April 2023

Following the publication of the government response to the consultation on the forthcoming Biodiversity Net Gain Regulations (see our March 2023 news article), Natural England has now published an update to the Biodiversity Metric. The revised version is termed v4.0 and supersedes the previous version v3.1, albeit accompanying guidance from Natural England advises that assessments already commenced under the previous version should continue under that version, unless there is a request to upgrade to the newer version by the consenting body (or the client).

Assessments which are upgraded to utilise v4.0 are, however, likely to show little difference in outcome to v3.1, as although the upgrade is badged as ‘major’ in nature, in reality few parameters have in fact been updated. Indeed, feedback from the recent Government Response to the Technical Consultation on the Biodiversity Metric shows that most of the significant comments from the consultation that require addressing within the Metric have not been captured by the current update. Rather these have been held back for incorporation into the next major update, with many of the changes in the current update being primarily of a cosmetic nature, so as to increase the user friendliness of the tool.

Of the few technical parameters to have received an update, the most significant relates to an update to the spatial risk multiplier (SRM). This now applies to any overall off-site net gains in area habitat, hedgerow or watercourse units, whereas previously the SRM was applied only to all off-site creation and enhancement, making it difficult to achieve off-site gains in many scenarios. Accordingly, this is considered to be a helpful update.

Other helpful updates include the incorporation of additional commonly encountered habitats, such as tall ruderal (forbs) and willow scrub, that were previously absent and the update of the condition assessment parameters for certain habitats including commonly encountered habitats such as grassland, hedgerows and woodland.

This version of the Biodiversity Metric is likely to form the version referenced by the Secretary of State when the Biodiversity Net Gain Regulations are enacted, which is anticipated to be in autumn 2023.

In conclusion, the update to the Biodiversity Metric is welcomed, albeit we are somewhat disappointed that this is limited in its extent and that many of the issues flagged in the technical consultation will not be addressed until the next major update.

Further details on Biodiversity Metric 4.0 can be found here.

Read our ‘Briefing for developers. Biodiversity Net Gain – The Basics’ here

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