What is biodiversity net gain (BNG)?
Biodiversity net gain is a way of creating and improving natural habitats by ensuring that they are left in a ‘measurably better state’ than before any development has taken place.
Its role in environmental restoration and tackling climate change has been firmly embedded in the fabric of UK planning regulations since its launch in February 2024. Under the measure, developers are now legally required to deliver at least a 10% improvement in biodiversity – the ‘net gain’ – as part of each building project. They must demonstrate the steps taken to preserve, protect and enhance any habitats found on site – including increasing their size, and identify specific off-site compensatory BNG unit provision when necessary.
The biodiversity value is measured in standardised units, considering criteria such as habitat size, quality, location and type. These units can be lost through development – or generated through efforts to create and enhance habitats.
In England, BNG is mandatory under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021).
How to measure biodiversity net gain
An official biodiversity metric must be used to measure how many units a habitat contains before development, according to the Department for Environment, Food and Rural Affairs. The metric will also measure how many units are needed to achieve the 10% BNG, with the data integrated into planning applications to ensure smooth approval.
The mandatory requirement to deliver the 10% improvement places BNG at the forefront of future UK development, particularly in light of the government’s commitment to building 1.5m new homes over the next five years.
Carried out in the right way, the regulation should provide and safeguard natural places and green landscaping that can shape and enhance wildlife habitats, rivers and streams, and hedgerows, ensuring that land development and management activities result in a positive impact.
According to Natural England, when designed and delivered well, BNG can secure benefits for nature, people and places, and for the economy, offering a new route for the development of homes, businesses and infrastructure.
Who does biodiversity net gain impact?
BNG will change how landowners, developers, and conservationists approach land management and the opportunities it offers.
For developers looking to demonstrate environmental responsibility and gain planning permission for their projects, achieving BNG is vital. By harnessing expertise in the sector, they can identify opportunities for on-site and off-site BNG delivery.
BNG can create long-term investment opportunities for landowners and farmers through allowing the delivery of net gain on their land and selling the units to developers. Farmers may choose to repurpose their less productive land for BNG projects, generating income while supporting environmental restoration and sustainable land management.
CSX research indicates that approximately 10% to 15% of farmland could be effectively repurposed for BNG accreditation, offering an alternative revenue stream in the face of diminishing agricultural subsidies.
Ultimately, this mandatory requirement to deliver better quality habitats will allow wildlife to thrive, people and communities to enjoy the health-boosting benefits of attractive green spaces and have a positive effect on our economy and climate change.
The different ways to achieve BNG
Balancing environmental and economic priorities is paramount when considering the developers’ approach to BNG commitments, which often require a combination of on-site and off-site solutions.
On-site BNG focuses on improving habitats within the boundaries of development projects, while off-site BNG, which often involves partnerships with farmers and landowners, addresses biodiversity needs beyond the project scope.
The financial viability of a development can often be challenged by on-site delivery; while off-site BNG requires long-term commitments to improving biodiversity on suitable land. Recent DEFRA guidance on off-site delivery provided clearer frameworks for landowners and developers to streamline the process for biodiversity improvements.
What developers have to do
According to the government’s rules, developers must initially confirm whether their development is exempt from BNG when they apply to the local planning authority for planning permission. If it isn’t, they must avoid loss of habitat and deliver at least 10% BNG, either on-site or off-site – or ‘as a last resort’ by buying statutory biodiversity credits. They must also ensure maintenance of the habitats that are created or enhanced for a minimum of 30 years.
What land managers have to do
Land managers, including landowners, farmers, estate owners or managers and land agents, can sell off-site BNG units on their land to developers as a potential source of income and nature recovery work. They need to sign legal agreement with a local authority or responsible body explaining how the process will work and that they will maintain and monitor the delivery of the units for 30 years. Once applications are accepted, the details of the scheme will appear on the biodiversity gain sites register.
How can CSX’s BNG expertise help its clients?
Embracing the changes and opportunities that BNG offers is crucial for long-term environmental planning and restoration at the heart of future development. Adjusting future strategies to align with the legislation is more important now than ever to ensure farmers and developers play a leading role.
Here at CSX, our experts have more than 2,500 BNG units from around the country that are progressing through local planning authority processing and aim to add to the Natural England Gain Site Register in the near future.
We can use our advanced data tools to help farmers and land managers to create and deliver BNG and maximise their revenue from sustainable land management. For help and advice email us at contact@csxcarbon.com, call us on 01609 786655, or visit our contact page.