Reflections on the Scottish Government’s announcement to develop a Scottish biodiversity metric – by Sarah Kydd CEcol MCIEEM

Sarah Kydd, CEcol, Associate Ecologist at WSP and Member of CIEEM Scotland Policy Group, shares her thoughts on the emerging biodiversity metric in Scotland to support planning and development.

Scotland will not be subject to the mandatory requirements for Biodiversity Net Gain (BNG) as required in England under the Environment Act, but under policy 3b of National Policy Framework 4 (NPF4), EIA development will need to achieve significant biodiversity enhancements. Through the publication of the Scottish Government’s commissioned report undertaken by the SRUC (Scotland’s Rural College) titled ‘Research into Approaches to Measuring Biodiversity in Scotland’[1], it recommends a biodiversity framework or standard is needed, making use of multiple metrics or tools for different sectors to monitor biodiversity. The report highlights the priority biodiversity indicators that were identified across policy sectors, including habitat condition, species, ecological connectivity and ecosystem integrity/function, as well as the need for an approach to consider wider ecosystem benefits. The report specifically makes the recommendation that the Biodiversity Metric be adapted to include connectivity measures, as well as the other priority indicators noted above. Following release of the report, the Scottish Government has announced that NatureScot will be developing a metric to support the delivery of policy 3b.

In the lead up to NPF4 being finalised earlier this year, and following its publication, there has been much discussion around how positive effects for biodiversity would be measured in a tangible, measurable and consistent way across Scotland. Looking back over the last few years initial indications appeared that Scotland may move in a different direction to using metrics, with the Scottish Biodiversity Post-2020 Statement of Intent[2], stating that NPF4 would set out proposals which will deliver positive effects for biodiversity from development, without the need for overly complex metrics. This led to plenty of stimulating discussion across the industry around how Local Planning Authorities (LPAs) would assess that positive effects could be achieved.

CIEEM has produced two briefing notes around BNG in Scotland, one looking more widely at what BNG is and how it works, with examples of organisations in Scotland undertaking BNG on their projects to evidence biodiversity enhancements[3], and one considering what LPAs would need to consider if adopting a BNG requirement[4]. In 2022, CIEEM held an event following the draft publication of NPF4 to give LPAs the opportunity to discuss the emerging NPF4, and also the Developing with Nature Guidance (which is relevant to local developments under policy 3c[5]. The attendees noted the positive language and great ambition of policy 3, but concerns were raised over delivery of the policy without a clear process and over the resources within LPAs to implement  the policy requirements.

These concerns were further highlighted through a survey into LPA ecological expertise and capacity in Scotland, issued by CIEEM in collaboration with the Association of Local Government Ecologists (ALGE)[6].  Respondents identified that a lack of enforcement staff to ensure compliance posed a high or very high risk to LPA’s ability to implement NPF4 and 22% said they have no current ecological resource or expertise available. The survey led to calls from Scottish Environment LINK for planning departments to have more expertise to deliver the environmental ambitions set out in NPF4, highlighting the urgent need for increased capacity and expertise at local levels[7]. It is of note that the SRUC report also highlights concern that Scotland does not have the capacity to assess development proposals to ensure they demonstrate biodiversity enhancements, noting the need for clear guidance and resources to upskill regulators, while also identifying a need to review Scotland’s capacity to deliver surveys (e.g. surveyors competent in UKHab and MoRPh accreditation). This is likely to mirror experiences in England where the ecological sector has needed to rapidly upskill, with CIEEM being one of the main providers in training on use of the Natural England Metric and UKHab survey. It would be prudent to draw on this training, adapting it to a Scottish audience once the new metric is developed.

It is encouraging that a Scottish metric is on the horizon. This should provide a much-needed framework for developers to follow and to allow LPAs to assess planning applications’ adherence to policy using a standard, measurable approach. For those familiar with the Natural England Metric, the key recommendations from the Measuring Biodiversity in Scotland review are to look at the following adaptions to the Natural England Metric for use within the Scottish planning sector:

  • Refining Natural England’s forthcoming irreplaceable habitats list to reflect habitats in Scotland Inclusion of irreplaceable habitats, Annex 1 habitats and Scottish Biodiversity List habitats within the Metric and assign an appropriate distinctiveness rating (consulting with key stakeholders to validate this) – n.b. following the Natural England Metric methodology biodiversity values are not calculated for irreplaceable habitats
  • Identify an approach to ensure peatlands are correctly accounted for
  • Review trading rules to be in-line with Scottish planning, biodiversity and woodland creation policies, and consider linking trading rules to both distinctiveness and condition
  • Review Metric 3.1 translation between Phase 1 and UKHab and ensure fit for purpose in Scotland
  • Review approach to strategic significance and risk multipliers for use in Scotland and allow flexibility in risk multipliers to reflect site conditions
  • Review approach to assigning spatial risk
  • Review condition assessment criteria for Scottish use

For those less familiar with the Natural England Metric, the tool is used to assign habitats a biodiversity value, with the value being calculated based on the distinctiveness and condition of a habitat, along with its strategic significance. The adaptions recommended would ensure that habitats are valued in a Scottish context (i.e. considering their rarity) and that the condition of habitats are reviewed in the field using condition assessment criteria appropriate to Scotland. The strategic significance considers the geographic location of the habitat taking account of local plans and strategies for biodiversity. To calculate if positive effects have been achieved (i.e. a net gain in biodiversity value), the post development value is assessed, looking at the habitat type to be created (and its associated distinctiveness), the targeted condition, and risk factors; notably the difficulty to create a habitat, and the time to do so. The values within the Natural England Metric will be reviewed in a Scottish context to take account of local conditions and current knowledge around habitat creation and restoration in Scotland.

The recommendations given for adapting the Natural England Metric detail the need to engage experts to ensure the adaptations are fit for purpose in Scotland. It is known from previous CIEEM Scotland BNG events[8] [9], that there are number of projects across Scotland where a BNG approach has been applied. It would be great to see this knowledge and experience drawn upon.

It certainly is an exciting time for ecological consultants in Scotland. No doubt there will be a steep learning curve for the industry once a Scottish metric is developed, but having a tangible, measurable and consistent approach should ensure that policy 3 can deliver the positive effects it intends.

About the Author

Sarah Kydd, CEcol is WSPs BNG lead in Scotland and is regularly involved in projects using a BNG approach to demonstrate positive effects for biodiversity.

Sarah also sits CIEEM’s Scotland Policy Group, through which she has been involved with CIEEM Scottish events on BNG and co-authored the CIEEM briefing note on BNG in Scotland for LPAs. 

If you are interested in the work of the Scotland Policy Group and would like to get involved, please contact


[1] McVittie, A., Cole, L., McCarthy, J., Fisher, H., and Rudman, H. (2023) Research into Approaches to Measuring Biodiversity in Scotland, Final Report to Scottish Government.









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