A guide to achieve Biodiversity Net Gain in England - Cypher Climate Brokers
Biodiversity Net Gain (BNG) has been back in the headlines recently, with developers and environmentalists closely following the outcomes of the latest round of consultations on the legislation. While changes for smaller sites may be on the horizon, some developers are still getting to grips with BNG, and for those early in the process, it can feel complex.
To shed light on the practicalities, we spoke with Charlie Cliff from Cypher Climate Brokers, a leading provider of off-site BNG units, to understand how offsetting works, how it fits into the wider BNG framework, and how it can offer a straightforward, workable solution when onsite delivery isn’t possible.
What are the requirements of Biodiversity Net Gain?
“Since 2024 it’s been a legislated requirement that all new developments must achieve a 10% increase in the biodiversity value of a proposed development site. Any ecological uplift must be retained for 30 years.” Charlie explains.
“There are some key exemptions, on self and custom builds for example. The extent to which BNG applies to ‘small sites’ is currently a matter of contention.
Under BNG legislation, development cannot begin until a Habitat Management and Monitoring Plan (HMMP) has been submitted to the planning authority.”
How do you deliver the net gains?
“The legislation sets out a clear hierarchy of delivery preferences, which must be considered when planning BNG:
- On-site habitat enhancement
- On-site habitat creation
- Off-site BNG unit procurement: involves developers purchasing biodiversity units from a source other than the development site to meet the mandatory 10% BNG requirement in England.
- Statutory biodiversity credit purchase – a last resort
Charlie adds: "When you can’t deliver net gains onsite, there are still multiple ways to achieve compliance. Statutory credits are extremely expensive, so developers are incentivised to comply through off-site solutions."
Is BNG required on irreplaceable habitats?
“When it comes to irreplaceable habitats, Biodiversity Net Gain compensation must be agreed directly with the planning authority. The government provides a published list of irreplaceable habitats, which includes ancient woodland, ancient and veteran trees, blanket bog, limestone pavements, coastal sand dunes, spartina saltmarsh swards, Mediterranean saltmarsh scrub, and lowland fens.”
What should you include in a BNG plan?
Charlie from Cypher explains: “The plan should clearly show how the net gain will be achieved. This includes onsite habitat plans, reference numbers of off-site unit purchases, and proof of any statutory unit purchases.
Planning authorities have 8 weeks to respond to submitted BNG plans. Discussing a draft plan with the council may accelerate this process.”
BNG unit prices
Charlie notes: “The market is still in its infancy, so prices are difficult to gauge. The cheapest statutory unit has been set at £42,000, while off-site units generally fluctuate between £20,000–£30,000 depending on purchase size. These prices can be exceeded for higher distinctiveness habitats. Developers are estimated to need around 7,000off-site units per year.”
Offsite BNG units and offsetting
Offsite units, like those provided by Cypher, are a vital part of the BNG puzzle, making the legislation workable in practice.
"The truth is, for a myriad of reasons, BNG can’t always be delivered onsite," Charlie explains. "Obviously, onsite delivery is always the first preference, but offsite units provide the next option for those developers who can’t fully meet BNG onsite. Working with us makes that part of the process easier, and that’s something we’re really proud of."
DEFRA’s spatial risk multiplier further encourages developers to purchase units locally: the further the habitat is from the development site, the less valuable it becomes, and the more units are required.
How do you secure off-site units?
“Most commonly, section 106 agreements and conservation covenants create legally binding contracts to create or enhance a habitat and manage it for 30 years. Working with an experienced broker can help developers navigate these agreements efficiently and ensure compliance without delays. We have access to BNG delivery sites across the whole of England so are well-placed to help developers of all sizes secure off-site units. Having this extremely wide range of available units enables us to provide the developer with the units they need, whilst ensuring the delivery site aligns with the development timelines so there are no delays to the onsite start."
Conclusion
Despite potential changes to metrics, Biodiversity Net Gain remains a key discipline and a regulatory requirement that will affect most major developments. Compliance doesn’t have to be complex. By prioritising onsite gains and supplementing them with carefully sourced off-site units, developers can meet legislative obligations, manage costs, and deliver tangible benefits for local biodiversity. With the right expertise, offsetting turns BNG from a regulatory challenge into a practical and achievable solution.
