The critical document you must provide to comply with Biodiversity Net Gain (BNG) is the Biodiversity Metric (either the Small Site Metric or the Statutory Metric).
The metric sheet has several internal checks, which can result in red alerts. While these can appear concerning, the presence of red alerts does not necessarily mean that the metric sheet is inadmissible. In fact, for certain purposes, a red alert is a necessary component.
Important: Amber Alerts are acceptable!
This page discusses red alerts that may appear on the excel sheet. if there are amber alerts this does not render your metric sheet invalid. Please refer to this guide for more details.
The metric sheet can be used for different purposes. This page sets out when red alerts are acceptable (or even required) in certain conditions for the Small Site Metric (SSM).
Purpose: To demonstrate that a 10% BNG gain can be secured solely with on-site gains
Tab 3 (Desktop Assessment)
18. Any designated sites on or within 500m of the site? May be Amber or Green but must NOT be red
19. Any priority habitats on or within 500m of the site? May be Amber or Green but must NOT be red
23. Site walkover completed? May be Amber or Green but must NOT be red
Tab 4 (Supporting Information)
There should be no red alerts on this page.
Tab 5 (Area Habitats)
There should be no red alerts on this page.
Tab 6 (Hedges & Lines of Trees)
There should be no red alerts on this page.
Tab 7 (Watercourses)
There should be no red alerts on this page.
Tab 8 (Headline Results)
Next Steps May be Amber or Green but must NOT be red
There should be no red alerts on this page.
Purpose: To demonstrate eligibility for a de minimis exemption
The metric sheet is the only definitive way to assess whether or not habitats have been "impacted" by a development. However, if the metric sheet is being provided for this purpose, there will be a number of areas where they may be red alerts and still be acceptable:
Tab 3 (Desktop Assessment)
18. Any designated sites on or within 500m of the site? May be Amber, Green or Red.
19. Any priority habitats on or within 500m of the site? May be Amber, Green or Red.
23. Site walkover completed? May be Amber or Green but must NOT be red
Tab 4 (Supporting Information)
There should be no red alerts on this page.
Tab 5 (Area Habitats)
The top box should state All Key Rules Satisfied and be Green. There must not be a red box stating "Input errors present on Sheet"
Error Check 1 must be green
Error Check 2 must be green
Error Check 3 must be green
Error Check 4 must be green
Broad Habitat Type Medium Distinctiveness Habitats may be green or red
Medium and Low Distinctiveness Band may be green or red
Trading Satisfied? Boxes may be green or red
Tab 6 (Hedges & Lines of Trees)
The top box should state All Key Rules Satisfied and be Green. There must not be a red box stating "Input errors present on Sheet"
Error Check 1 must be green
Error Check 2 must be green
Error Check 1 must be green
Distinctiveness and Habitat Type may be green or red
Trading Satisfied? Boxes may be green or red
Tab 7 (Watercourses)
The top box should state All Key Rules Satisfied and be Green. There must not be a red box stating "Input errors present on Sheet"
Error Check 1 must be green
Error Check 2 must be green
Distinctiveness and Habitat Type may be green or red
Trading Satisfied? Boxes may be green or red
Tab 8 (Headline Results)
Next Steps May be Amber or Green but must NOT be red
There should be no red alerts on this page.
Purpose: To demonstrate 10% BNG gain being secured with off-site units
Because the SSM does not have an off-site tab, the metric sheet will have red alerts if you use off-site units to secure your 10% uplift. You will need to provide additional evidence (either a statutory metric sheet with the off-site sheets filled in or evidence like a certificate that you can secure off-site units).
Tab 3 (Desktop Assessment)
18. Any designated sites on or within 500m of the site? May be Amber or Green but must NOT be red
19. Any priority habitats on or within 500m of the site? May be Amber or Green but must NOT be red
23. Site walkover completed? May be Amber or Green but must NOT be red
Tab 4 (Supporting Information)
There should be no red alerts on this page.
Tab 5 (Area Habitats)
The top box should state All Key Rules Satisfied and be Green. There must not be a red box stating "Input errors present on Sheet"
Error Check 1 must be green
Error Check 2 must be green
Error Check 3 must be green
Error Check 4 must be green
Broad Habitat Type Medium Distinctiveness Habitats may be green or red
Medium and Low Distinctiveness Band may be green or red
Trading Satisfied? Boxes may be green or red
Tab 6 (Hedges & Lines of Trees)
The top box should state All Key Rules Satisfied and be Green. There must not be a red box stating "Input errors present on Sheet"
Error Check 1 must be green
Error Check 2 must be green
Error Check 1 must be green
Distinctiveness and Habitat Type may be green or red
Trading Satisfied? Boxes may be green or red
Tab 7 (Watercourses)
The top box should state All Key Rules Satisfied and be Green. There must not be a red box stating "Input errors present on Sheet"
Error Check 1 must be green
Error Check 2 must be green
Distinctiveness and Habitat Type may be green or red
Trading Satisfied? Boxes may be green or red
Tab 8 (Headline Results)
Next Steps May be Amber or Green but must NOT be red
There should be no red alerts on this page.
HOWEVER, the applicant SHOULD provide the following for validation:
Credible evidence that the applicant can source the requisite off-site units from registered providers of Biodiversity Units; OR
A statutory metric with the off-site tabs completed; OR
Proof of receipt of HM Government statutory credits.