Defra invited views on proposals to change the way that the biodiversity net gain BNG) policy is applied to minor, medium and brownfield development. A parallel consultation asked for feedback on the implementation of biodiversity net gain in nationally significant infrastructure projects. The LGA’s response supports proposals to streamline BNG but we want to retain key parts of the policy to protect the investment in environmental improvement.
Opening comments
The implementation of Biodiversity Net Gain (BNG) is a significant culture change in the way we treat new development, creating a huge potential to improve the natural environment. Treating housing and the nature environment with equal importance is the only way to create a sustainable future for local communities and it should never be seen as a trade-off between the two.
We welcome Defra’s confirmation that government is committed to BNG, and that the department has no plans for significant reform or repeal of the legislation. BNG has been a steep learning curve on all sides. We need clarity about the future so local planning authorities can focus on delivery rather than responding to mixed messages and rumours. This is a good point to take stock of BNG and look for opportunities to streamline processes in the light of experience. This should stop short of deregulation in order to protect the environmental benefits of the policy and ensure that local communities see the benefit of new development.
Improving the implementation of biodiversity net gain for minor, medium and brownfield development
Extending the categories of development exemption from BNG
Where there is a good case for streamlining BNG processes we support a change, and that should be the focus for government.
Local planning authorities share government’s intention to help SME builders as they are an important part of the local economy. It was always likely that the implementation of BNG for small sites would be difficult, as the LGA flagged in correspondence with Ministers from the previous government. BNG should not be excessively onerous, but it is a significant change that all sides will find easier once there is a body of knowledge and experience to draw on.
The large housebuilders have the capacity to employ their own in-house experts on BNG, as well as trade bodies to support them and share good practice. Small and medium sized developers are unlikely to have the same capacity and are more reliant on the local planning authority to provide advice and support. Defra may wish to look at the potential to expand the support for local planning authorities through the Planning Advisory Service (PAS) as well as ensuring that local planning authorities are properly resourced to provide support and advice to small developers.
Responding to the proposed exemptions:
Removing the existing exemption for self and custom build housing and replacing it with a new exemption for a 'single dwelling house' on a site of less than 0.1 hectares is simple and clear. From the local planning perspective, the self-build exemption is complicated to administer in practice. The LGA supports the targeted revision to the existing exemptions for self and custom build development (option 1 in the consultation paper). This will streamline the process for applicants and reduce the pressure on local authority capacity.
Implementation has been challenging for smaller sites, and extending the 'de minimus' exception could help. Feedback from councils suggests that an area threshold of 50 square metres would be supported by many, although individual councils will have different views.
BNG has proved helpful for local planning authorities in urban areas in retaining mature trees on development sites, as the removal of a mature tree requires a developer to provide an equivalent amount of biodiversity plus uplift. In addition to setting the size of the site the revised definition should also factor in the presence of mature trees, so that there is an incentive to retain them as part of the development.
We would welcome engagement with government on flexibilities that would enable BNG on small sites to support local, council-led tree planting programmes. Solutions could include creating local habitat banks and using BNG alongside other tools such as Section 106 agreements.
We do not support a full exemption for all minor development. This reduces the environmental benefits of BNG, and with time and support SME developers will gain confidence and experience in the BNG process.
Some member councils have a relatively high number of small developments, for example in rural areas. Exempting them from BNG could have a negative effect on plans for nature recovery.
Defra proposes to create new exemptions for certain types of development, for example temporary development. Our concern is that they will create issues with interpretation and definitions. While we recognise the challenges that Defra is trying to address, there may be other solutions or work arounds that do not require changes to BNG processes.
Streamlining the BNG metric
The biodiversity net gain metric will need to evolve over time, and individual councils will share their experiences of using with the metric. Defra and Natural England will need to co-design changes to the metric with stakeholders including local government. Working with PAS would be a sensible way to do this.
Increasing flexibility to go off-site for minor development
We recognise that access to the BNG market has been a challenge for small sites, but this is not a reason to relax the hierarchy that promotes on-site BNG as the best option. Defra should look at other options and one solution would be to give local authorities flexibility to operate a local tariff or credit system, making it easier for developers to provide fractional units.
Introducing biodiversity net gain for National Significant Infrastructure Projects (NSIPs)
Introducing biodiversity net gain for NSIPs is a real opportunity to support nature through infrastructure development. We welcome government’s government commitment to implementation and clarity on the May 2026 deadline.
Our comments relate to the impact of the proposals on local government, rather than addressing the full set of consultation questions.
Engagement with local planning authorities
It is positive that the consultant paper recognises the importance of early engagement with local planning authorities, and the link to local nature recovery strategies. Guidance would be useful as well as sharing good practice in delivering complex projects.
Changing the statutory biodiversity metric for NSIPs
The consultation paper proposes that the statutory biodiversity metric will be amended to allow NSIPs to deliver off-site biodiversity gains in any of the local planning authorities the scheme is in without incurring a spatial risk multiplier penalty (page 14 of the consultation paper).
BNG for NSIPs should follow the same principle as the existing BNG policy and incentivise biodiversity to be delivered in the same areas where the development takes place. This is clear and transparent to residents and builds confidence that BNG will benefit those in the immediate of development. It also ensures that the connection between BNG delivery and the local nature recovery strategy is maintained. However, NSIPs come in a wide variety of projects and delivering BNG onsite will be easier on some types of projects than others, for example laying a pipeline across several local authority boundaries. We do not support the proposed change to the metric but recognise that some flexibility is needed. This could be done on an individual project basis in negotiation with local partners, or by considering whether certain types of NSIP project could be allowed greater flexibility on the spatial multiplier.
Skills, expertise and resources
Successful implementation for BNG in national infrastructure requires skills and expertise as well as regulation and guidance. BNG will be a learning curve for planning officers used to working with NSIPs, and ecologists used to BNG will need to understand the added dimensions of an NSIP project. Government needs to use the time between now and the implementation date to understand the resourcing requirements of local planning authorities and ensure that training and support is available, for example through the Planning Advisory Service.
Sharing knowledge from local planning authorities with experience of dealing with NSIPs will help others understand the tools they can use to recover costs and set up effective agreements for ways of working. Any other costs, such as preparation for the implementation of BNG for NSIPs should be covered by