CIEEM is deeply concerned that Ofgem’s draft determination weakens ambition on biodiversity compared to RIIO-2 by rejecting funding for 10%+ Biodiversity Net Gain (BNG) in non-statutory projects and biodiversity measures beyond legal requirements. This approach conflicts with Ofgem’s statutory duties under the Environment Act and Levelling Up Act, ignores strong consumer support, and risks undermining nature recovery, public acceptance of infrastructure, and the credibility of the RIIO framework.

CIEEM argues that 10% BNG should be treated as the bare minimum, with many stakeholders supporting 20% for major projects. Limiting funding to the legal baseline disregards long-term environmental, social and economic benefits, narrows the definition of consumer value, and places Ofgem behind other regulators such as Ofwat. Transmission networks have a critical role in delivering biodiversity corridors, climate resilience and natural capital benefits, at minimal cost to consumers.

CIEEM therefore urges Ofgem to reverse its position and reinstate funding for ambitious, non-statutory biodiversity commitments. We recommend supporting enhanced BNG, creating incentive mechanisms to drive ambition, ensuring monitoring and accountability, and expecting TOs to deliver additional measures where financial returns allow. Doing so would align regulation with public expectations, legal duties, and the urgency of tackling the climate and nature crises.