Rachel, Industry wide, March
Biodiversity Net Gain (BNG) can be a challenging topic, it is easy to get wrapped up in what could be needed for your planning application; however, your development may not need it at all. Always check if your development may be exempt from BNG using the government website before delving into the metric.
Some of these exemptions, accurate as of March 2026, include:
- If the development does not impact a priority habitat and impacts less than 25 square metres of on-site habitat or less than 5 metres of linear habitats like hedgerows.
- This means your development can be larger than 25 square metres but cannot impact more than 25 square metres of non-developed land. For example, 25 square metres of grass, overgrown previously developed land, or bare, undeveloped ground.
- Householder applications are also exempt, for example extensions or conservatories.
This can be challenging for ecologists, as we often don’t know the full details of each applications history, full intended use, or what size the redline must be from a planning perspective. It is always best to check and to include planning consultants in the decision process to ensure you are either exempt from or do require BNG.
Recent government announcements have suggested that these exemptions may change soon, with the potential for the size threshold to change, though there are no specific dates or changes as of yet. We will watch this space, make sure to keep updated!