31/08/2026
A small change to Biodiversity Net Gain could make a real difference to smaller development sites.
Since 6 August 2026, planning applications made on or after that date for development sites of 0.2 hectares or less are exempt from mandatory BNG, provided the development does not affect priority habitat on the site. The site area is assessed using the red-line boundary.
That matters because even quite modest residential schemes could previously require a biodiversity metric and a route to achieving the statutory 10% gain unless another exemption applied.
This does not mean biodiversity can simply be ignored. Existing habitats, trees, hedgerows, protected species and relevant planning policy can still be important. But for suitable smaller sites, the new exemption may remove a significant layer of assessment and administration.
It is another reason why the red-line boundary and existing site conditions should be considered carefully at the very start of a project rather than after a layout has been drawn.
Images are illustrative.