Biodiversity in the Planning System

It is widely recognised that biodiversity has its own intrinsic value, delivering a variety of ecosystem services whilst also enhancing our general wellbeing, as many of us have appreciated during lockdown. In recent years, there has been a growing realisation that solely protecting remaining areas with high biodiversity value, such as statutory and non-statutory designated sites, will not suffice in halting the major decline of biodiversity in the UK. Local Planning Authorities (LPAs) are legally required to have regard for conserving biodiversity in the exercise of all public functions. National and local planning policies are generally guided by the Mitigation Hierarchy model. This model sets out that developments must comply with the following:

  1. Avoid biodiversity harm
  2. Mitigate (only where adverse effects cannot be avoided)
  3. Compensate (only if options for avoiding and mitigating harm have been exhausted)

By building upon the concept of the Mitigation Hierarchy, the National Planning Policy Framework (2019) outlines that planning should seek to conserve nature and secure ‘net gains’ for biodiversity. The Government definition of development-related Biodiversity Net Gain (BNG) is ‘an approach to development that leaves the natural environment in a measurably better state than it was beforehand’. A key element of the BNG policy is that changes should be measurable. Natural England are currently working to produce a Biodiversity Metric which will provide ecologists and planners with a means of assessing changes in biodiversity value brought about by development.

It is understood that further details regarding BNG will be unveiled later this year once the Environment Bill 2020 has been passed by Parliament. This will outline the required percentage increase in biodiversity value which must be achieved through each development. The net gain requirement is expected to be set at 10% and this target has already been implemented by some LPAs.

The BNG approach cannot be applied to irreplaceable habitats or statutory sites and LPAs must continue to have regard for European Protective Species. It is essential that the presence of a protected species and the extent that they could be affected by the proposed development, is established by an ecological survey before the planning permission is granted. It is only possible to condition for such surveys in exceptional circumstances.

As the concept of Net Gain becomes embedded in planning policy, there is likely to be a continuous change in the dynamic between developers and local authorities. As the discussion surrounding biodiversity in planning continues to evolve, we will keep you up to date with a series of blogs.

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