Biodiversity Net Gain in the UK – Birds and Bees and British Standards – by Claire Wansbury

This August, the British Standards Institute launched a new standard: BS8683: Process for designing and implementing biodiversity net gain – Specification. 

Biodiversity Net Gain (BNG) is a relatively new approach in the UK, piloted over the last decade but now becoming mandatory in increasing numbers of local authority areas, and due to become mandatory across England under the Environment Bill. So, readers may wonder if now is the right time for a British Standard, or if it is too early. 

I am delighted to have been able to contribute to creating BS8683, and believe its creation at this time is essential. A change in existing systems that are not halting the decline in our natural habitats and species is vital, and commitment to BNG is commendable. However, to deliver for nature and for people it needs to be done well. Otherwise, the blunt tool that is a metric-based BNG approach could, sadly, risk doing more harm than good.   

Sound ecological expertise and robust application of the ‘mitigation hierarchy’ are key, and following BS8683 will require these. Ecological expertise is important, both to apply the metric correctly and to ensure that features, such as rare species, that are not included in the metric, are not forgotten. For any readers unfamiliar with the mitigation hierarchy, it is an approach I tend to refer to in talks as ‘common sense’ – the hierarchical approach is to try to avoid harm first, and then reduce harm as far as practicable, then look at restoration and only then aim to compensate for any unavoidable residual losses. Similarly, the Standard requires good record keeping and maintenance through the lifecycle of development projects. Having worked on major projects I very much recognise the need for such good practice, so the commitments made as a project is consented don’t risk getting lost as individuals or companies working on a project change over time. 

Some core parts of what is needed to make BNG work well are outside the scope of a British Standard, as they include policy and institutional approaches rather than the methods applied in individual projects. I see two aspects as key among these. The first is that BNG, as I mentioned above, is a blunt tool, so it will only work well if implemented alongside a strong system of policy and legislation to protect the rarest and best wildlife sites and species assemblages. Any temptation to reduce these would be misplaced. The second is that nature is complex and the BNG metric introduced in England is also complex, so expertise is needed in checking it has been correctly applied to projects. Errors can appear if inexperienced ecologists try to apply the system, and even the most experienced can make mistakes. This means local planning authorities (LPAs) need ecological expertise supporting their planning decision-makers. I have read for too many years now the fact that only about 1/3 of LPAs have in house ecologists, and I know some in this role who have to balance it alongside other roles such as advising on flood risks. Ringfenced funding is essential to make a system that supports sound planning decisions that deliver genuine BNG as part of sustainable development. 

So, in conclusion, I welcome BS8683, as an important step in creating a system where BNG is a force for good, alongside other policy and legislation, to help transform the UK from a nature-poor to a nature-rich nation.   

Claire Wansbury CEcol FCIEEM is an Associate Director of Ecology within Atkins. She is a generalist ecologist with particular interest in practical application of innovations to deliver genuine benefits for nature conservation and society. Contact Claire at:  

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