New Biodiversity Net Gain Exemptions 2026: What Do They Mean for Your Development?

The rules have changed, but does that mean your development is now exempt from Biodiversity Net Gain? Not necessarily.

On 6 August 2026, the Government introduced significant changes to Biodiversity Net Gain (BNG) requirements in England, including a new exemption for developments of 0.2 hectares or less.

For many smaller developments, this is welcome news, potentially removing the need for detailed BNG assessments and the associated costs.

However, the new rules aren't quite as straightforward as they might first appear.

At SJ Ecology & Environment, we're helping clients understand these changes, establish whether their projects qualify for an exemption and ensure the right ecological information is provided from the outset.

What Changed in August 2026?

One of the most significant changes is the introduction of an exemption for developments with a red-line site area of 0.2 hectares (2,000m²) or less.

For qualifying planning applications submitted from 6 August 2026, mandatory BNG no longer applies, provided the development does not negatively impact an on-site priority habitat.

Other changes include a new exemption for certain temporary developments, changes to the biodiversity gain hierarchy for minor developments and the removal of the previous self-build and custom-build exemption for new applications.

While these changes simplify the process for some developments, determining whether an exemption applies still requires careful consideration.

Why Accurate Habitat Mapping Matters

A site might be smaller than 0.2 hectares, but that doesn't automatically mean it's exempt. The presence of priority habitats, and whether the proposals would negatively affect them, can make a significant difference.

That's why accurate habitat identification and mapping remain essential.

At SJ Ecology & Environment, we take a detailed approach to understanding the habitats present on your site, their condition and how they relate to your proposals. We don't simply rely on aerial imagery or existing habitat maps. Where necessary, we undertake detailed site assessments to establish what's actually present on the ground.

Getting the baseline right means getting the advice right.

Understanding Priority Habitats

One of the most important considerations under the new rules is whether a development will negatively impact a priority habitat.

These habitats are recognised for their importance to biodiversity and include certain types of woodland, grassland, hedgerows and other valuable ecological features. However, identifying them isn't always straightforward.

A hedgerow might appear ordinary but could meet the criteria for a priority habitat. Similarly, an area of grassland may contain plant communities that aren't immediately obvious without a detailed assessment. Our experience in habitat classification, botanical identification and ecological assessments allows us to investigate these features properly.

We understand the importance of accurate identification, particularly where the outcome could determine whether your development requires a full BNG assessment.

Local Knowledge Makes a Difference

Every landscape has its own character.

The habitats found across Oxfordshire can differ considerably from those in Warwickshire, Sussex or elsewhere in the UK. Understanding local landscape character, vegetation communities and habitat types helps us interpret ecological features accurately and provide advice that's relevant to the site.

Our background in both ecology and landscape architecture also gives us a broader understanding of how habitats relate to local landscape character and development proposals. Rather than taking a one-size-fits-all approach, we consider the local environment, available ecological records and the specific characteristics of your site.

How We're Adapting to the New Rules

At SJ Ecology & Environment, we've been working with Biodiversity Net Gain since its introduction, and we're continually adapting our approach as legislation and guidance evolve. For smaller developments, our priority is now to establish whether an exemption could apply before recommending a full BNG assessment. This means reviewing site boundaries, assessing potential habitat impacts, identifying priority habitats and determining what evidence may be needed to support an exemption.

Where a full assessment isn't necessary, we'll explain why. Where further work is required, we'll provide clear recommendations and practical advice.

We believe you should only pay for the ecological work your project genuinely needs.

Do You Still Need an Ecologist?

Although the new exemptions may remove the requirement for a statutory BNG assessment, they don't remove other ecological and planning responsibilities. Protected species, designated sites and other ecological constraints may still need to be considered, regardless of whether BNG applies.

In some cases, a straightforward ecological review may be sufficient to help establish whether an exemption is appropriate. In others, a more detailed habitat survey may be necessary. The important thing is understanding your site and proposals before making that decision.

Let Us Take Care of It

Whether you're planning a small residential development, commercial extension or larger planning application, we're here to help you navigate the changing requirements.

We'll take the time to understand your project, assess the relevant ecological considerations and explain exactly what's needed.

No unnecessary assessments, no confusing jargon and no uncertainty about the next steps.

Just experienced professionals providing accurate, practical advice to help your project move forward.