Concept for - Biodiversity Net Gain (BNG) - what is it and when does it apply?

Biodiversity Net Gain (BNG) became mandatory for nearly all types of development earlier this year, bringing with it a new wave of considerations for developers which may affect the viability of developments. This article provides an overview of some of the key features of BNG.

What is Biodiversity Net Gain (BNG)?

The Environment Act 2021 introduced the requirement for new developments to provide a Biodiversity Net Gain.

This means that developers, must demonstrate that their development proposals will contribute a 10% improvement to natural habitats from the pre-development baseline and hence leave the environment in a better state than before the development.

This adds a new layer of complication and cost to many planning applications.

When does BNG apply?

BNG became mandatory for all applications for new major developments from 12 February 2024, and all applications for minor sites from 2 April 2024 and Nationally Significant Infrastructure Projects from late November 2025.

Developers need to decide how to achieve BNG

BNG can be achieved by developers in 3 ways:

  1. Provide the biodiversity gain on-site within the ‘red line’ of the development boundary;
  2. If developers cannot deliver BNG on-site, BNG can be delivered through a mixture of on-site and off-site. Developers can either make off-site biodiversity gains on their own land outside the development site or buy off-site biodiversity units on the market to meet the BNG requirement; and
  3. If developers cannot achieve on-site or off-site BNG, as a last resort they must buy statutory biodiversity credits from the government. The government will use the revenue to invest in habitat creation in England.

BNG and Section 106 of the Town and Country Planning Act 1990

Depending on the circumstances, BNG can be secured via a condition, or the provision can be secured on the land with a conservation covenant agreement or planning obligation in the form of a section 106 agreement with a Local Planning Authority.

The Environment Act 2021 requires that BNG is secured for 30 years.

Are there any exemptions for BNG?

Yes, some developments are exempt from BNG requirements. Read more in our article ‘Biodiversity Net Gain Exemptions‘.

For further information on how we can assist you with meeting BNG targets, guidance on if an exemption applies to your development or help with a Section 106 agreement please contact our Planning team.