The policy wording suggests that there will be a requirement for development to achieve a minimum 20% biodiversity net gain. It is understood that this aspiration has stemmed from the Oxford-Cambridge Arc Environmental Principles and exceeds that in the Environment Act 2021. Whilst Countryside are supportive of this approach to provide significant biodiversity improvements through development and are committed to achieving a net biodiversity gain of at least 10% across all their developments by 2025, this is clearly a high aspiration and it will be important to consider site specific requirements and the overall viability implications of all the Plan requirements considered collectively.
A suggestion to the wording is that this could be phrased as ‘the policy will require development to aim to achieve a 20% biodiversity net gain with a minimum 10% to be achieved’. By amending the wording in this way the onus is clearly on the applicant to meet the 20% wherever possible, but should there be a slight shortcoming (that would still result in an overall high net gain) this would not prevent otherwise acceptable development.
The mandatory minimum limit should reflect the legislative target. However, policy could still actively encourage schemes to exceed the minimum, recognising that those that do will be considered as a planning ‘benefit’ of development in sustainability terms (the greater the increase, the greater the weight attached to the assessment of benefit in any planning balance).
Ultimately, the aim of BNG is to leave the natural environment in a measurably better condition than beforehand. Therefore, if it can be robustly demonstrated that on-site provision is not achievable, the opportunity to measurably improve the natural environment of other appropriate receptor sites through off-site provision should still have a significant value attached to it.
The Councils should also consider alternatives to on site provision where the necessary biodiversity net gain cannot be achieved on site. This could include a range of options including biodiversity net gain ‘credits’ being able to be purchased from other donor sites in order to achieve appropriate levels.