The UK government has confirmed that biodiversity net gain requirements for nationally significant infrastructure projects will take effect from 2 November 2026, six months later than initially planned.
This extension follows criticism from industry groups about the lack of clarity on implementation, with the Biodiversity Net Gain Federation warning in early April that developers faced a regulatory vacuum just weeks before the original May deadline.
Defra’s parliamentary under-secretary Mary Creagh signalled the shift on 31 March, and the government formally announced the new timeline on 15 April, citing the need to finalise guidance and secondary legislation.
The policy, first introduced under the Environment Act 2021, already applies to smaller developments under the Town and Country Planning Act 1990, where a 10% biodiversity net gain has been mandatory since 2024.
For NSIPs — which include energy, transport and water projects approved via development consent orders — the same 10% target will apply, measured against the pre-development baseline and covering onshore sites down to the mean low-water mark.
Legal experts at Pinsent Masons note that while the objective mirrors the TCPA regime, the operational framework for NSIPs remains distinct, requiring developers to stress-test designs against forthcoming rules.
The government has committed to releasing updated biodiversity gain statements, a revised metric user guide tailored to NSIPs, and further guidance, though no sector-specific exemptions will be granted.
Meanwhile, Defra has confirmed an exemption for small development sites under 0.2 hectares, aiming to reduce administrative burdens and support the growth of the biodiversity net gain market.
A consultation is also underway on a potential exemption for residential brownfield sites, aligning with the government’s housing delivery strategy on well-connected urban land.
BNG Federation spokesperson Claire Traynor welcomed the NSIP approach as balanced but criticised the piecemeal handling of smaller site exemptions, warning that delayed impact assessments and unclear timelines risk prolonging uncertainty for investors and slowing nature restoration.
Why was the biodiversity net gain rollout for major infrastructure delayed?
The government delayed the rule to allow time to finalise guidance, secondary legislation and biodiversity gain statements after industry highlighted a lack of preparedness just weeks before the original May 2026 launch.
Will small housing developments still need to meet biodiversity net gain rules?
Sites under 0.2 hectares are now exempt from biodiversity net gain requirements, but a consultation is ongoing on whether residential brownfield sites should also receive an exemption to support urban housing goals.
