Biodiversity Net Gain:
where we are now and why it matters

Biodiversity Net Gain (BNG) is a planning rule introduced in England in 2024 designed to make sure new development leaves nature in a better state than before. 

BNG is one of the few policies that directly links development to nature recovery. Most developments are meant to deliver at least a 10% improvement in biodiversity, either within that local area or by funding habitat creation elsewhere. If it works properly, BNG could bring green spaces into communities, improve health and wellbeing, and help tackle the UK’s nature crisis.  

It could also play a key role in reducing inequality, providing people with access to nature who might benefit from it the most. But new research, laid out in the Green Gap report below, shows that it just isn’t happening. With so many exemptions and opportunities for developers to exploit loopholes, BNG now risks widening – not reducing – nature inequality.

Read the report.

Loopholes and exemptions are weakening the system

In practice, BNG is already being heavily limited by exemptions and loopholes, with ‘de minimis’ being the most significante  exemption. In theory,  it applies only where a development has a very small impact on nature. However, in most cases,  developers can self-declare that they qualify – without needing detailed evidence. 

Evidence from the first year of BNG shows how serious this problem is. Around 86% of planning applications have claimed exemptions, and the de minimis route alone has accounted for more than half of all cases. This means many developments are avoiding their responsibility to contribute to nature, even when they shouldn’t. 

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Having access to nature should never be reduced to a postcode lottery. It’s time for the UK Government to stop dismantling what should have been a world-leading policy, especially as those in society already missing out will be hit hardest. The BNG system must be restored so it delivers nature on everyone’s doorsteps as originally intended.

Carl Bunnage, Head of Nature Policy in England, RSPB

Instead of fixing this loophole, the UK Government is introducing further exemptions. It’s  committed to a new exemption for housing developments under 0.2 hectares. By the Government’s own figures, this could remove around 51% of developments from the system and will have a major impact on more deprived areas – where most housing developments fall below this threshold.  

Read the report.

Taken together, these loopholes and exemptions risk creating a system where many developments no longer deliver for nature. That means fewer green spaces and fewer benefits for the people who need them most – undermining a key principle of the policy.

The 2025 and 2026 consultations

You might have noticed that, over the last two years, environmental charities like the RSPB asking for your help to raise the alarm. Recent UK Government consultations have shaped the direction of BNG, and they are a key reason why campaigning matters right now.

The first consultation was last year, and as a result of it the UK Government confirmed a commitment to the 0.2 hectare exemption for small sites.  A new consultation, which launched in April 2026 and is now closed, is proposing further exemptions, particularly for housing on brownfield land (land that has been used before for development). These proposals could increase the number of exempt developments by another 15%.

At the same time, the UK Government has said it will consider the de minimis loophole, but it has not yet taken action to fix it – that’s why we need to keep the pressure up. Together, these exemptions and loopholes could lift the vast majority of housing developments out of the BNG system. That would be a gutting of the system, and a huge loss to both nature and communities.

This means that overall, despite voices from nature lovers across the country, the system is moving in the wrong direction. Instead of closing loopholes, more exemptions are being added. Instead of strengthening BNG as it begins to take effect, it is being chipped away.

These consultations are important because they shape how the policy works in practice. They decide whether BNG delivers real improvements for nature, or whether it becomes a policy that applies to only a small number of developments.

What the Green Gap report tells us about BNG and inquality

Wildlife and Countryside Link (LINK)’s recent report the Green Gap (developed with the support of the RSPB and other partners) highlights the huge opportunity that has been missed.

Read the report.

Across England, access to nature is already deeply unequal. Around 7.4 million people live in areas with no immediate access to biodiversity. In the most deprived neighbourhoods, nearly a third of people have very limited access to nature, almost three times the rate in the most affluent areas. 

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More than four in five applications in the most deprived areas could fall outside BNG requirements altogether.

Green Gap report

This inequality exists within towns and cities, not just between urban and rural areas. 

The report shows that BNG exemptions risk making this worse. The small sites exemption will affect deprived areas more, where most developments are smaller. In some places, around 82% of applications fall below the threshold. The de minimis loophole is also used more frequently in these same areas. 

The proposed brownfield exemption would make this even worse. Brownfield land is much more common in deprived areas, and nearly 78% of people live near at least one piece. A broad exemption like this would remove biodiversity improvements from the very communities that already lack access to nature and should benefit most from BNG. 

It would also affect future generations. Many of the homes planned for the coming years will be built on brownfield land. If these developments are exempt people moving into them may never see the benefits BNG is meant to deliver

That’s why we need a full and working BNG system. Otherwise, we risk large areas becoming ecological deserts, where development continues but nature does not recover – because it simply isn’t given the support that’s needed.

The BNG system was designed to benefit everyone. It was meant to ensure that, as new homes are built, communities become greener and healthier and developers contribute fairly to restoring nature. We have to keep speaking up so one day it can.

Read the report.