Regime 8 of 8 · Land & nature
Biodiversity net gain — the basics
Correct as at 27 July 2026.
This is a short primer on where biodiversity net gain (BNG) sits within the eight UK environmental regimes — what it requires, in force since when, and what is about to change.
It is not the full implementation guide: for the metric calculation, off-site credits and habitat-banking detail, our sister site has the fuller reference (linked below).
The one distinction that matters: BNG is a planning condition, not an annual report.
It binds a development through its planning permission — it does not sit in a directors' report or a regulator return the way SECR or packaging EPR do.
What it requires
Most development in England granted planning permission must deliver a 10% measurable gain in biodiversity value, calculated against a statutory metric. Where the planning authority judges the on-site increase significant, habitat enhancement must also be secured and maintained for at least 30 years.
It has been in force for all planning applications — major and minor alike — since 12 February 2024. There was never a separate "small sites" commencement: minor development instead had a temporary exemption that lapsed for applications made on or after 2 April 2024.
What is changing
From 6 August 2026, a new 0.2 hectare exemption applies where no on-site priority habitat is affected, temporary planning permissions of up to five years become exempt, and the self-build exemption is removed.
Applications made before that date are grandfathered under the old rules — see the full list of exemptions for exactly which developments qualify.
BNG for nationally significant infrastructure projects follows separately, from November 2026.
(Some commentary gives the date as 31 July 2026 — the statutory instrument itself says 6 August.)
Where it sits among the eight regimes
BNG is one of the regimes we treat as "compulsory now" where you are building, alongside SECR, ESOS, packaging EPR, Simpler Recycling, and permit and abstraction returns. Of those, ESOS is the one whose scope catches people out: the qualification thresholds are a two-limb test applied across the whole UK group.
The wider sustainability reporting standards impose no equivalent duty. UK SRS S2 is climate-only, and S1 only catches nature where it is financially material, treated as comply-or-explain under the FCA's current proposals with relief until 2029 — so BNG remains the one place UK law imposes a hard nature-related number on a business today.
See the full eight-regime map for how it compares with the other seven, including packaging EPR.
For the full guide
The metric calculation, the priority order between on-site delivery, off-site units and statutory credits, and how BNG evidence connects to TNFD-aligned nature disclosure are covered in depth by our sister site's biodiversity net gain implementation guide.
This page is independent reference material, not legal or planning advice.
Check the primary sources below before relying on a threshold or a date.
Sources
- Environment Act 2021, Schedule 14 — legislation.gov.uk
- The Biodiversity Gain (Town and Country Planning) (Amendments and Transitional Provisions) (England) Regulations 2026 — legislation.gov.uk, SI 2026/790, in force 6 Aug 2026
- Understanding biodiversity net gain — Defra / Natural England, updated 2 Jun 2026