Biodiversity Net Gain – On Site Or Off Site?

A report by Cornerstone Barristers, Strutt & Parker, Bellway Homes, Rural Solutions and Environment Bank has looked at the comparative value of on-site vs off-site Biodiversity Net Gain (BNG) for restoring nature.

The report notes that whilst BNG is beginning to work well within the planning system and the requirement to restore the natural environment whilst delivering on the government’s growth agenda, it is felt that BNG can make a much greater contribution to nature restoration than is currently enabled by the policy.

One major change would be getting the right balance between on-site and off-site delivery.  Early indications suggest that over 95% of BNG is being done on-site with current implementation including a preference for on-site rather than off-site delivery. There is growing evidence that generally on-site delivery offers far lower biodiversity benefits than off-site.  The report states that “when tested against the various criteria of the Global Biodiversity Framework and the Convention on Biological Diversity, it is highly unlikely that on-site BNG will make any significant contribution to enhancing and protecting biodiversity. By contrast, off-site BNG sites offer far greater opportunities for making a meaningful uplift to biodiversity, secured for many decades.”

Research shows that large areas can support more individuals of a species and a greater variety of species than small areas and provide more opportunities for providing food and shelter. Nature conservation is about creating as large a site as possible, connected to other habitats and landscapes.  On-site provision leads to small areas and fragmentation compared to off-site provision and is much more likely to be affected by human disturbance leading to loss of biodiversity.  Providing “green space” on a development is not the same as delivering biodiversity.

Biodiversity loss in the UK has been in excess of 60% since 1970 (when data was first collected and analysed) with many well monitored groups such as birds showing declines of over 90%. Biodiversity loss in the UK has mainly been caused by intensive agriculture, built development and also climate change. The trend towards regenerative farming practices, if they become mainstream, could improve biodiversity, but it isn’t possible to reclaim areas of built development and improve biodiversity in those areas.

Off-site BNG therefore seems favourable long term, but it is essential that the proper management and monitoring systems are in place.

The report recommends:

• The government should favour developers purchasing off-site BNG units from professionally managed off-site providers.
• Local planning authorities (LPAs) should champion off-site BNG delivery in their area
• LPAs should be held more to account, by way of more effective compliance monitoring of on-site BNG
• If the on-site approach is to be retained then it is essential that a level playing field for on-site and off-site provision is created
• Communications around BNG from central government should be reviewed and the benefits of the approach to society and to biodiversity should be more clearly and widely publicised.

There are certainly opportunities for landowners and habitat bank providers to put in place the appropriate off-site provision. Not only will this be beneficial for biodiversity but also will free up areas within development sites which might otherwise be allocated for on-site provision for development.

In the words of Joni Mitchell, back in 1970, “Don’t it always seem to go that you don’t know what you’ve got ‘til it’s gone? They paved paradise and put up a parking lot”.  Proper management of BNG should be an important part of the future development process.

For legal advice regarding BNG, habitat banks, etc, contact the Agricultural team at Wilson Browne, or call 0800 088 6004

Read the full report here: BNG-on-site-off-site-comparison-final-3.pdf