What happened
Biodiversity net gain (BNG) became mandatory for nationally significant infrastructure projects (NSIPs) in England on 2 November 2026, as Matt Mace reported for edie. Defra's guidance for NSIPs sets out the rule: developers who apply for a development consent order (DCO) on or after that date must deliver at least a 10% net gain in biodiversity. The legal basis is Schedule 15 to the Environment Act 2021, which inserts Schedule 2A into the Planning Act 2008.
The main points from the guidance:
- Measured in biodiversity units. Habitat value is scored with the statutory biodiversity metric, by size, condition, location and type. A project submits a single metric calculation with its DCO application, even if it is spread across several sites or council areas.
- Gain statements carry policy weight. The biodiversity gain statements Defra published in June 2026 explain how NSIPs must calculate, deliver and report BNG. They have the same effect as if they were in the relevant national policy statement, and a project must follow its statement to receive consent.
- England and the shore only. BNG applies as far as the mean low-water mark, not to the marine environment beyond it. Cross-border projects count only habitats in England, and the gain must be delivered in England.
- Worst case when the route isn't fixed. Where a route or footprint is uncertain, the baseline must reflect the realistic worst-case habitat loss, using the maximum construction parameters.
Ordinary developments have been under a separate 10% BNG rule in the Town and Country Planning Act 1990 for some time; from 6 August 2026, planning applications for sites of 0.2 hectares or below are exempt (Defra).
What it means for your business
For most businesses, nothing changes directly. The duty falls on NSIP developers. But the projects it covers include many of the power stations, grid connections and transport schemes that decide how fast the UK's electricity gets cleaner, so it shapes the cost and design of the infrastructure every business relies on.
If you are in the supply chain, as a contractor, ecologist, landowner or land manager, expect more questions about habitats and biodiversity units. Developers can meet BNG with on-site habitat, off-site units bought from land managers, or statutory credits as a last resort, so land that can be improved for nature may find new buyers.
It is a separate measure from carbon. A solar farm or grid line can cut emissions and still have to show a habitat gain. Nature and carbon are reported side by side, not netted against each other, and buyers asking about one increasingly ask about the other. Our guide to nature and biodiversity reporting for small firms covers how that conversation usually starts.
What to do now
- If you develop or work on an NSIP, read the gain statement for your sector and the Defra guidance before your DCO application, and get an ecologist to set the baseline with the statutory metric.
- If you own or manage land, see Defra's guidance for land managers on selling off-site biodiversity units.
- If you supply these projects, keep your own environmental records in order: customers on large infrastructure schemes often ask for carbon and other environmental data alongside a bid.
