Registration of a gain site on the Biodiversity Gain Site Register is a critical step under the mandatory Biodiversity Net Gain (BNG) framework. Whether you are a landowner seeking to create a site that can generate biodiversity units or a developer analysing the availability of off‑site biodiversity units, understanding the process, including costs, required forms and common pitfalls, is essential. Civity supports landowners navigating this regime, aligned with the statutory requirements and best practice.
Why register a site?
Registering land on the Biodiversity Gain Site Register enables a land parcel to become eligible to deliver units that a development subject to BNG can use. Specifically:
- A development site must deliver a minimum 10% net gain in biodiversity value compared with the pre-development biodiversity value (using the statutory biodiversity metric tool).
- Where on-site habitat enhancements cannot deliver sufficient biodiversity units to meet the 10% net gain requirement, developers must rely on off-site gains. These units must be sourced from a biodiversity gain site that is both legally secured (via a Section 106 agreement or Conservation Covenant) and formally registered on Natural England’s Biodiversity Gain Site Register.
- The register supports transparency in the biodiversity gain market by recording where habitat creation or enhancement will occur, ensuring units are not double counted.
- Once a gain site is registered, the landowner may sell biodiversity units, and the developer may use them to meet their biodiversity net gain requirements.
At Civity we advise both sides, landowners on the registration process and developers on sourcing units from registered sites, while ensuring alignment with the biodiversity gain plan and associated obligations.
Key prerequisites: What you must have before applying
Before submitting your application to register a gain site, you must ensure the following are in place:
- Proof of land ownership (title deeds or valid lease/authorisation) for the land you propose to register.
- A map setting out the boundary of the site.
- A legal agreement securing the site for at least 30 years, either a Section 106 (with the relevant local planning authority) or a conservation covenant with a responsible body.
- A completed calculation using the statutory biodiversity metric (or metric tool) showing existing habitat (pre‑development biodiversity value) and proposed habitat (post‑development biodiversity) for the gain site.
- A Habitat Management and Monitoring Plan (HMMP) covering the management and monitoring of the habitat for the long‑term (30 years at least).
- A local land‑charge search certificate (so the legal agreement is registered).
Application process, forms & costs
Forms and submission
- There is a dedicated application form for registering a gain site and a separate (or combined) form if you are also allocating off‑site biodiversity units from your gain site to a development.
- The form requires details of the applicant (landowner or agent), the site (grid reference, hectares or length for linear habitats), the legal agreement, habitat information per metric row (creation or enhancement), and the development details if allocation to a development is sought.
- Supporting documentation must be submitted when requested (within a specified period), and you must pay the registration fee within 28 days of the request.
Costs
- The registration fee for a gain site under the current guidance is £639.
Additional costs you should budget for (not fees to the government but necessary costs) include:
- Ecological surveys and metric tool calculation (pre‑development and projected post‑development values)
- Legal fees for drafting the legal agreement (Section 106 or conservation covenant)
- Preparation of the HMMP and associated monitoring plan
- Land‑charge search and mapping costs
- Long‑term habitat management and monitoring (30‑year horizon)
- Ongoing costs for brokering units and allocating on the register
Post‑submission
- Once you submit the application and payment, you will be notified within six weeks whether your application is accepted or if further information is required.
- If accepted, you will receive a unique gain site reference number, and your site will appear on the public register.
At Civity: How we support you
We provide tailored support for both landowners and developers in respect of the Biodiversity Gain Site Register and related BNG obligations.
For landowners: We provide a free desk‑based assessment, support preparation of the metric calculation, liaise on the legal agreement (Section 106 / conservation covenant), develop the HMMP, and submit the registration documentation on your behalf. We work alongside the landowner throughout the entirety of the scheme as their monitoring ecologist. Civity also broker and pool the unit sales.
For developers: We provide off-site biodiversity units from already registered sites, verify the metric calculations and allocation, and assist in completing the biodiversity gain plan.This ensures the process is efficient, aligned with regulation and free from surprise delays or pitfalls.
Conclusion
Registering a biodiversity gain site is a non‑optional component of the BNG framework for off‑site units. The process includes the legal securing of land, metric calculation, HMMP preparation, form submission and payment of the fee. Landowners who register sites open the opportunity to sell biodiversity units, while developers gain access to compliant units and support for their biodiversity net gain plan. By understanding the costs, forms and common pitfalls, you are far better equipped to proceed with confidence.
If you are considering registering a site, or if you are a developer seeking to allocate or purchase units, we recommend contacting our team at Civity for an initial consultation and next-step outline.
