What Developments are Exempt from BNG?
The list of exemptions for the UK's new Biodiversity Net Gain (BNG) mandate is very narrow and specific. These exemptions ensure that BNG does not hinder very small-scale developments. It's important to note that exemptions are designed to be exceptions, not the rule. Below, we provide a brief explanation and examples of the types of developments that are exempt.
The BNG De Minimus Exemption
The "de minimis" exemption applies to the smallest planning applications, such as street furniture (e.g., benches, disability ramps). Specifically, this exemption applies to developments that:
1. Do not impact priority habitats, and
2. Impact less than 25 square meters of non-priority onsite habitat, and
3. Impact less than 5 meters of non-priority linear habitats.
All three criteria must be met to qualify for this exemption. Note that "impact" is legally defined as a negative effect as measured by the metric itself, excluding non-zero rated habitats like tarmac or existing buildings.
This exemption is challenging to claim due to numerous grounds that may disqualify a site. For example, the presence of trees on or near the site might mean the exemption is not appropriate if any trees are impacted. A typical example of a de minimis exemption would be an accessibility ramp added to an already developed area without disrupting existing habitats. Developers can use publicly available datasets on priority habitats to check eligibility.
Householder Developments
This exemption covers modifications or extensions to existing houses. If it is a householder application, the development is automatically exempt.
Biodiversity Gain Sites
Exemptions are also applied to off-site biodiversity gain projects where enhancements would require an additional 10% net gain. Specifically, the following site developments are exempt:
- Developments that solely enhance biodiversity to meet the BNG planning condition for another development through off-site habitat enhancements, or
- Developments undertaken to fulfill the BNG planning condition for the purpose of permitting public access or use for educational or recreational purposes without a fee.
Small Scale Self-Build and Custom Housebuilding
Exemptions apply to self-build and custom-build developments with no more than nine dwellings on sites no larger than 0.5 hectares. All houses must meet the legal definition of self-build or custom builds, which is very specific and cannot be broadly claimed.
High-Speed Railway Transport Network
This exemption covers development associated with the remaining phases of the high-speed transport network.
Implications and Considerations
While these exemptions exist, applicants should remember that BNG is a general condition for planning permission. Exemptions are exceptions, and it is often possible to implement BNG regardless of them. All developers should consider BNG whenever submitting a planning application, regardless of exemptions.