Regulation
Biodiversity Net Gain, explained
A planning requirement for new development in England to deliver a measurable 10% uplift in biodiversity value, calculated against a pre-development baseline. Applied to major applications from February 2024 and to minor applications from April 2024.
Applies to
- Planning applications for major development in England (since February 2024)
- Minor development (since April 2024)
- Certain exemptions for householder applications and biodiversity-neutral development
Key dates
- February 2024: BNG becomes mandatory for major development applications.
- April 2024: BNG becomes mandatory for minor development applications.
- 2026: Reforms announced to simplify the metric and clarify management obligations.
The 10% uplift
Every planning application must demonstrate a 10% net gain in biodiversity value calculated using the statutory Biodiversity Metric. The baseline is the site as it exists pre-development; the post-development value is calculated for the finished scheme including any on-site habitat creation or enhancement.
The hierarchy: on-site, off-site, statutory credits
The regulation expects developers to achieve the gain on-site first. Where that is not feasible, off-site gains can be delivered through a habitat bank or a bespoke off-site scheme. Statutory credits (bought from the government) are a last resort and priced deliberately high to disincentivise them.
The 30-year management obligation
Whichever route delivers the gain, the habitat has to be secured and managed for 30 years. That obligation runs with the land, so it needs to be in the section 106 agreement or a conservation covenant. For a housebuilder, this is the operational tail that catches people out: someone has to be responsible for the wildflower meadow, the hedgerow or the pond decades after the last home has sold.
Common questions
Can I meet BNG entirely off-site?
Yes, but the local authority will scrutinise why on-site delivery was not feasible. A pure off-site solution is more expensive per unit of biodiversity than an on-site one, once you factor in the habitat bank margin.
How does Ubrix help with BNG?
Ubrix does not run the Metric itself (that is an ecology-consultant tool) but it stores the BNG assessment against the scheme record, tracks the on-site habitat creation as a build workstream, and holds the 30-year management plan alongside the completion pack.
Take it with you
Full guide as a PDF
The long-form guide includes worked examples, evidence templates and a per-plot checklist. Free, no signup.
Download the Biodiversity Gain 2026 reforms guide (PDF)Related explainers
- Awaab's Law Part of the Social Housing (Regulation) Act 2023, Awaab's Law sets legally binding timescales for social landlords to investigate and fix hazards in tenants' homes, particularly damp and mould. Applies in phases from 2025 to 2027.
- Building Safety Levy A tax on new residential development in England, introduced to fund the removal of unsafe cladding on existing buildings. Charged per square metre of internal floor area at Building Control sign-off. Rate varies by local authority and whether the site is previously developed land.
- BSA The primary piece of post-Grenfell building safety legislation. Creates the Building Safety Regulator, defines Higher-Risk Buildings, introduces the Gateway process, and imposes the Golden Thread requirement.
See how Ubrix captures the evidence you need.
Ubrix stores compliance evidence against the plot, not on shared drives. Timestamps, sign-offs and documents come out as an audit trail on demand.