Biodiversity net gain requirement now in force for majority of developments

In England, BNG is mandatory under Schedule 7A of the Town and Country Planning Act 1990, as inserted by Schedule 14 of the Environment Act 2021.

BNG requires that a development boosts biodiversity by at least 10% and has been required for large sites since February this year.

As of Tuesday, BNG requirements now extend to small developments, except for certain exempt classes of development, which include householder developments.

Concerns have been expressed about the metric throughout its implementation, particularly by the Royal Town Planning Institute (RTPI).

In February 2024, a survey conducted by the RTPI revealed that 81% of planners in the public sector needed further 'guidance, advice and support' in relation to BNG.

It also found that 68% of all planners need more staff and skills, and 61% require more case studies of BNG best practice.

The RTPI has highlighted "uncertainties" around BNG, particularly on how local planning authorities should treat mandatory BNG in local plans, how sites for inclusion in local plans should be assessed, and how site allocations should be made.

Guidance on BNG and how it impacts local planning authorities was issued by the Department for Environment, Food & Rural Affairs and was last updated in February 2024.

The document details what local planning authorities must do before granting planning permission, reviewing plans submitted by developers relating to BNG, and approving the plans, among other things.

Adam Carey