Biodiversity Net Gain for major infrastructure projects – new guidance 

From 2 November 2026, Biodiversity Net Gain (BNG) will become mandatory for new nationally significant infrastructure project (NSIP) applications in England.

Bringing BNG into the NSIP system is an important next step for nature. It will ensure that much needed major infrastructure is delivered while also protecting and restoring nature at scale.   

To help developers prepare, we have today published guidance setting out how BNG should be considered throughout the design and consenting process. The guidance builds on the final biodiversity gain statements and initial guidance published earlier this year, details of which were set out in our June blog.   

Covering all NSIP sectors, the guidance explains how BNG requirements can be met, encouraging developers to consider BNG from the earliest stages of project design and engage with relevant stakeholders to inform their proposals.   

The guidance also delivers on the recommendations of the Nuclear Regulatory Taskforce Review to introduce a streamlined BNG framework for NSIPs, which means:  

• BNG applies only to habitats impacted by development, rather than the entire development site  

• biodiversity gains can be delivered either on site or off site in the first instance   

• streamlined requirements apply where developments have temporary impacts  

The guidance can be viewed here:  Biodiversity net gain: nationally significant infrastructure projects - GOV.UK 

We encourage NSIP developers to familiarise themselves with the guidance, feedback on it, and use it to support the preparation of their applications ahead of 2 November 2026.   

Further guidance changes for BNG  

We have also updated two existing BNG guidance pages to improve their useability and clarify how they apply to NSIPs as well as planning applications:   

• How to treat irreplaceable habitat for BNG  

• What you can count towards BNG  

What’s next for BNG?  

As set out in our July blog, the first phase of BNG reforms for smaller sites, including the 0.2 hectare exemption, came into force on 6 August 2026.  

Work is underway on the second phase of reforms which include:   

• an exemption for development whose primary objective is to conserve or enhance biodiversity   

• a targeted exemption for development that enhances parks, playing fields and public gardens   

We will also make some changes to the statutory biodiversity metric. These include measures to address some of the specific challenges that BNG can pose for brownfield developments with open mosaic habitat, and changes to the way spatial risk is assessed for area habitats by using Local Nature Recovery Strategy areas only.

 These changes will require the statutory metric act paper to be amended and laid before Parliament, and we will confirm timings and further details in due course.

We will provide transitional arrangements and guidance for projects using the current statutory biodiversity metric when the updated metric is introduced.  

Brownfield consultation  

The consultation on a potential additional targeted exemption for certain residential brownfield development closed on 10 June 2026.

All responses and evidence submissions are being analysed and the Government will respond to the consultation in due course.