New Biodiversity Net Gain Legislation Announced

The UK government has announced the draft secondary legislation that will provide the framework for the new Biodiversity Net Gain (BNG) policy coming into effect in 2024. BNG aims to ensure development leads to an overall increase in biodiversity.


What is Biodiversity Net Gain?

Biodiversity Net Gain requires most new developments to leave biodiversity in a measurably better state than before. Under the new rules, housing, commercial, and infrastructure projects must demonstrate at least a 10% increase in habitat value for wildlife compared to the site’s pre-development baseline. Developers can achieve Net Gain on-site, off-site, or through purchasing statutory credits from the government, which must be as a last resort.

When will the BNG legislation start?

The BNG obligations will apply to most major planning applications, except exempt developments, from January 2024. Smaller sites below set thresholds, defined as 'not major developments' – developments below the threshold are defined slightly differently here – will need to deliver BNG from April 2024. The policy will also apply to Nationally Significant Infrastructure Projects like roads, rail, and energy from late 2025.

What is the New Secondary Legislation?

The government has published six Statutory Instruments (SIs) providing the legal basis and specifics for implementing Biodiversity Net Gain. SIs allow ministers to set practical details to enable laws passed by Parliament, like the Environment Act 2021 in this case, to operate on the ground.

The SIs cover areas like:

  • Establishing a public register of off-site habitat sites used to deliver Net Gain

  • Setting fees and penalties for the operation of the register

  • Listing exempt development types not required to provide BNG

  • Defining “irreplaceable habitats” subject to alternative compensation arrangements

  • Integrating Net Gain within the planning application process

  • Further regulations and guidance for developers, planners, and landowners on implementing the framework will follow.

BNG will deliver ambitious improvements

Biodiversity Net Gain signifies a major step up in ensuring development happens sustainably alongside protecting nature. The 10% minimum target aims to deliver substantial overall improvements at a national scale while allowing suitable flexibility. Robust habitat assessments will help guarantee quality outcomes.

With the legal basis now confirmed, 2024 will see Biodiversity Net Gain start transforming how development impacts nature across England’s towns, cities, and countryside.


It is great to see the final corner and edge pieces of the Biodiversity Net Gain jigsaw in place this week. We are looking forward to seeing 2024 bring a new flow of investment in habitat, hedgerow and river creation – and for the process to work well for nature, developers and landowners alike.
— Chris Fry, CEO Accelar

If you’re a landowner or developer and interested in finding out more about Biodiversity Net Gain, please get in touch, or visit our BNG Finder service website.