BNG is changing, but what impacts are there for local authorities?
Biodiversity Net Gain (BNG) has been reshaping how development and nature interact since its mandatory rollout began in 2024. Now, with a fresh package of government updates published in April 2026, things are evolving again, bringing impacts for local authorities and their internal teams.
It is worth noting that BNG impacts local authorities in three distinct ways:
- As a local planning authority (LPA) determining applications and approving gain plans (and potentially monitoring compliance);
- As a developer (bringing forward their own projects); and
- As a landowner (with the potential to host off-site habitat gains and generate biodiversity units).
Each capacity brings its own set of opportunities and pressures, and the latest changes announced by the Government affect all three roles.
What's new?
The government has published its responses to two BNG consultations, alongside launching a further, new, public consultation.
In summary:
- Proposed “simpler” rules for smaller developers, but potentially more work for LPAs. A new 0.2 hectare area-based exemption is expected by end of July 2026 (subject to Parliamentary scheduling), with further exemptions for temporary permissions (up to five years) and biodiversity-focused development. For minor development, off-site gains will be treated equally to on-site habitat creation. LPAs may need to update application forms, guidance, training and policy documents, and manage transitional arrangements carefully (particularly for applications submitted mid-phase).
- The biodiversity metric is being updated. Changes include how spatial risk is assessed, improved identification of urban habitats, and, importantly, a move from Excel-based tools to a digital, integrated service. This will require LPAs to adapt their processes and training accordingly.
- Spatial risk is being re-calibrated around LNRS boundaries. he spatial risk multiplier will be assessed by reference to Local Nature Recovery Strategy areas rather than distance, meaning off-site gains within the same LNRS area as a development will attract lower spatial risk. For LPAs, this strengthens the link between BNG delivery and local nature recovery priorities and may affect the viability of off-site gain sites in your area.
- NSIPs: legislation is being published. Nationally Significant Infrastructure Projects (e.g. major roads, energy and water schemes) will be required to deliver BNG from 2 November 2026. The statutory framework has already been activated, with new secondary legislation having been made this month. The regime becomes operative once a Biodiversity Gain Statement is designated. This is relevant for authorities with NSIPs coming forward in their areas.
- A new consultation on residential brownfield exemptions closes 10 June 2026. Councils with significant brownfield pipelines should engage: Biodiversity Net Gain - considering a targeted exemption for residential brownfield development - Defra - Citizen Space. The outcome could meaningfully affect BNG obligations on sites you are either permitting or developing yourselves.
Most of these changes are not yet in force but are expected to be implemented before this summer; until then, current BNG requirements apply in full.
Whilst the changes aim to make BNG more proportionate, they may create a busy transitional period. LPAs should track legislative updates, revise internal processes and guide applicants accordingly — and where councils act as developers or landowners, they should assess how evolving exemptions and metric changes affect their own projects and land strategies.
We are always very happy to discuss all things environmental and BNG – please contact Helen Gill: helen.gill@brownejacobson.com
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