Net Benefit for Biodiversity

National Planning Policy in Wales requires that every development delivers a net benefit for biodiversity. It states that ‘development should not cause any significant loss of habitats or populations of species, locally or nationally and must provide a net benefit for biodiversity. In doing so planning authorities must also take account of and promote the resilience of ecosystems.’ (from Planning Policy Wales 11, 2021). 

A net benefit means that a development should leave biodiversity and ecosystems in a better state than before. This should ideally be provided by improving and creating habitats on site, and maintaining them in the long term. If this is not possible, habitats can be created or improved elsewhere. Guidance from the Chief Planner for Wales in 2019 states that developments that do not provide net benefit for biodiversity should be refused.

Net benefit for biodiversity goes beyond mitigation and compensation – the benefits provided for nature should be in addition to any compensation for lost or degraded habitats.

It is important to note that the Net Benefit for Biodiversity principle in Wales is different from the Biodiversity Net Gain system applied in England. Biodiversity Net Gain uses a special metric to measure the biodiversity before and after development, and developers must deliver at least a 10% biodiversity gain, which must be maintained for at least 30 years. Welsh planning policy does not specify how much benefit should be delivered, or how long it should be maintained – it is up to each local planning authority to decide what is appropriate and proportionate to the scale of the development.

Welsh planning policy also emphasises the need to promote ecosystem resilience. This reflects the Section 6 Biodiversity Duty which requires public bodies (including local planning authorities) to ‘maintain and enhance biodiversity in the exercise of functions in relation to Wales, and in so doing promote the resilience of ecosystems, so far as consistent with the proper exercise of those functions.’ (from the Environment (Wales) Act 2016).

In practice, this means that a planning application should consider the possible effects of the proposed development on the diversity, extent, condition and connectivity of ecosystems within and beyond the site and look to improve them as part of the Net Benefit for Biodiversity.