Biodiversity Net Gain (BNG) is a planning principle which seeks to ensure that, following development, the natural environment is left in a measurably better state than it was in before.

It will be mandatory for all local planning authorities in England to require at least 10% BNG on all planning applications that meet the criteria set by Defra, with small development sites remaining exempt until April 2024. Initially pledged in the Environment Act 2021 to come into force in November 2023, the rules were delayed to January 2024 and eventually launched on 12 February.

However, analysis by Wildlife and Countryside Link (Link) reveals that Biodiversity Net Gain will fail to go beyond “offsetting” in most Local Authorities.

The Environment Act 2021 allows Local Authorities to set net gain requirements above 10% in their Local Plans. However, nature organisations say that the vast majority of local authorities are set to go no further than mandatory 10% Biodiversity Net Gain minimum requirements.

Tony Juniper, Chair of Natural England, said recently that “biodiversity net gain is really about keeping things as they are”.

Based on Freedom of Information requests sent to the 317 local authorities in England, the figures show that just 26 local authorities (8%) have either committed to, or are considering, BNG requirements above the mandatory requirement of 10%.

Further key findings from the study. Out of 317 local authorities in England [2]:

  • 293 local authorities (92%) currently have no policy on Biodiversity Net Gain in place and will only be committing to the mandatory 10% when BNG becomes compulsory.
  • 26 local authorities (8%) have a current target of around 10% BNG that will continue after it becomes mandatory.
  • Just 2 local authorities, Guildford & Worthing, have adopted BNG policies of 20% into their local plans currently (for Worthing this applies to land that has been previously developed only). This is just 0.6% of local authorities.
  • 18 local authorities including East Devon, Canterbury and West Oxfordshire have emerging* BNG policies above 10%. These range up to 30% for Kingston Upon Thames and Tower Hamlets.
  • A further 6 local authorities including Birmingham, Herefordshire and Greater Cambridge are seriously considering BNG policies above 10%.
  • Just 24 authorities were found to have active targets on Biodiversity Net Gain ahead of the 10% rule becoming mandatory on 12th February 2024, with the vast majority at or around 10%

Richard Benwell, CEO of Wildlife and Countryside Link, said: “We really welcome the introduction of mandatory net gain. Done well, it could help turn around the decline of species and habitats, from dormice and red squirrels to meadows and woodlands, and give communities more natural spaces to enjoy.

“But the law is too lenient. It will make no dent at all in the £5bn annual gap in funding for nature recovery. Added to concerns about Local Authorities’ capacity to enforce the rules, there’s real concern that net gain will only amount to a glorified offsetting scheme. While 10% may help prevent a decline, Government must support much higher ambitions to restore nature.

“The local success stories revealed today show that there’s real appetite among Local Authorities to go further for nature, but there’s a real risk that without support many areas lose out on this opportunity. The Government should publish clear guidance to support Local Authorities to go further for nature and raise the bar for biodiversity net gain.

Rebecca Pullinger, Lead Policy Advocate in the Woodland Trust’s conservation team, said: “Nature is in crisis, with for example, just 9 per cent of our woods are in good ecological condition. We need an ambitious approach to turn this around. Done well, Biodiversity Net Gain could be part of this, but a 10% gain is not enough. Government must empower local authorities to raise the bar – by providing clear guidance to local authorities on how this can be done. A bold approach is needed to inspire the vital protection, restoration and creation of nature rich habitats for the benefit of communities and wildlife across the country.”

Developers have been providing less green space as part of new developments over past decades, resulting in fewer green spaces for residents of newer developments to enjoy. BNG could turn this around as it aims to ensure that after a development project like housebuilding, the natural environment is left in a better state than it was before, for example by creating new habitats such as woodland or by restoring areas such as wetlands. Benefits of this include more homes for declining wildlife, boosting public health through access to nature spaces, and helping protect communities against extreme weather including floods and heatwaves.

But nature experts have warned that 10% is too low to achieve a net gain in habitat and wildlife populations. The Chair of Natural England, Tony Juniper, acknowledged this publicly in January, saying 10% BNG was ‘about keeping things as they are’ and may not deliver a net gain for nature.

Recommendations include:

  • Support local planning authorities in raising their ambition above the national 10% minimum and consider increasing the national minimum net gain to more than 10%.
  • Publish a consultation on the definition, expanded list, and compensation principles for irreplaceable habitats.
  • Reverse the decision to enable the selling of excess units.
  • Improve the monitoring and enforcement of onsite delivery, through requiring onsite gains to be registered on the BNG register and providing guidance and support for local planning authorities to carry out enforcement if BNG is not delivered.