We know many of our clients have been waiting for important news on Biodiversity Net Gain (BNG) exemptions, and we now know the first of these will kick in on Thursday 6th August.
To set the scene, in April, Defra announced that the proposed changes to BNG would be drawn up following a consultation that took place in 2025. The new regulations impact BNG for projects that require planning permission under the Town and Country Planning Act.
Here’s a rundown of the changes:
- The previous de minimis rule remains in place, but there’s an additional exemption for sites where the red line boundary is less than 0.2 ha AND no priority habitats will be lost (a 0.2 hectare area is 2000m2, e.g. a 20m x 100m strip, or a 44.72 m by 44.72 m square).
Worked example1: A disused filling station forecourt has a red line boundary area of 0.3ha, with a narrow strip of scrub habitat along one edge totalling 15m2. This is BNG exempt under the previous de minimis rule.
Worked example 2: A site has a red line boundary of 0.18 hectares. The area comprises semi improved grassland. This site is also BNG exempt, under the new “under 0.2ha” rule.
Importantly, this new 0.2 ha rule does not apply if onsite priority habitat is negatively impacted – this includes native hedges, woodland, lowland meadow etc. The definition of ‘negatively impacted’ means if the development decreases the biodiversity value of a habitat. In these cases, the 10% minimum gain requirement of BNG will still have to be met. The Preliminary Ecological Appraisal (PEA) we provide for you will identify if priority habitats are present or not. (Don’t forget that any pre-emptive clearance of a site is heavily penalised in the BNG metric, with ecologists instructed to go back to aerial photographs from January 2020 to determine which habitats were present, and to use the precautionary principle when applying habitat type and condition, so it’s important to get us on board early before any site work is done).
- Defra will remove the BNG exemption currently in place for self and custom build development, but many of these will be covered by the new 0.2 ha exemption.
- Entirely temporary developments where planning permission has been granted for five years or less, are exempt. This is an uplift from the previous “under 2 year” temporary development exemption. Again though, this does not apply if onsite priority habitat is negatively impacted.
- There’s a change to the biodiversity gain hierarchy for minor development; minor planning applications over 0.2ha that aren’t exempt from BNG can go straight to offsite provision of BNG units if they would like to. This means that schemes of 1-9 dwellings that remain subject to BNG will now have off-site BNG treated equally to on-site BNG. If off site units are needed, CEC can provide these from our parent organisation’s habitat bank, which is registered with Defra and already making sales. More here.
It’s important to note that in the case of planning already approved, a Section 73 application cannot be made to remove BNG. An entirely new planning application must be made if this option is desired.
Finally, just a reminder that these exemptions only apply to BNG. They don’t apply to other ecological surveys, so species and habitats surveys still need to be completed, and the relevant documents must be submitted for planning. If you aren’t sure what you need, please contact us for free advice.
We’ll keep you updated on the latest guidance and what it means in real terms for householders, developers and landowners via our newsletter (sign up here). If you have any questions, do book a free 15-minute call with a CEC ecologist via our Contact page.
