Biodiversity Net Gain – TCPA lessons learned and NSIP predictions

In this session Trevor Ivory (Partner) and Henry Jeffreys (Senior Associate) consider statutory Biodiversity Net Gain (BNG) and how it has been working in the context of Town and Country Planning Act (TCPA) projects since its first introduction in February 2024. They also look forward to plans for BNG for Nationally Significant Infrastructure Projects (NSIPs), currently planned from May 2026.

The session discussed:

An overview of the BNG system under the TCPA, the deemed condition and the biodiversity gain plan requirement.

The experience so far for:
o Developers, including:
• Early strategic site selection to consider where and how BNG could be provided taking into account costs and availability of offsite biodiversity units and impacts on viability
• How to set the redline for the development with BNG requirements and viability in mind (eg application fee, cost of onsite/offsite BNG)
• Particular issues for reprovision of rare habitats, viability issues for small sites and the biodiversity metric hierarchy of provision (onsite, offsite units (cost by distance) and statutory biodiversity credits)
o Landowners, including:
• How BNG use might affect land negotiations including amount of land sought and the price paid for land used for onsite BNG
• The market for biodiversity units and how this is developing
o LPAs including:
• The different ways to secure BNG – by condition, s106 and conservation covenants
• When/how the LPA will discharge the BNG condition and concerns the LPA may have over enforcement of the biodiversity gain plan
o For Landowners, LPAs and Developers including:
• timing of securing the onsite BNG, offsite units and credits and how this ties in with pre-commencement discharge of the BNG condition
• biodiversity of brownfield land including calculating the BNG uplift, and availability of urban off-site units

On NSIPs they discussed:
o The 2025 consultation which delayed the implementation for NSIPs from November 2025 to May 2026
o The proposal for front loading the BNG requirement
o On-site and off-site gain being considered as equal on the BNG hierarchy, to reflect the large scale nature of schemes
o Voluntary provision of BNG in current schemes prior to implementation of a statutory scheme
o Viability implications of BNG for nationally significant infrastructure, including implications for land take