Biodiversity Net Gain FAQs
Clear answers to common questions about Biodiversity Net Gain
Biodiversity Net Gain (BNG) is still new to many people involved in planning and development.
This page answers common questions based on how Biodiversity Net Gain works in practice.
General questions
Biodiversity Net Gain is a planning requirement that requires most developments to deliver a measurable improvement in biodiversity, typically a minimum of 10%.
Biodiversity Net Gain applies to most developments that require planning permission in England, although some exemptions exist depending on the type of development, location, and site characteristics.
Biodiversity Net Gain is assessed at the planning stage and is usually secured through planning conditions or obligations.
Understanding the requirement
If your development involves changes to habitats and requires planning permission, it is likely that Biodiversity Net Gain will need to be considered as part of the planning process.
No. While the biodiversity metric underpins Biodiversity Net Gain, you do not need to understand how it works in detail to comply, provided the process is handled clearly and correctly.
On-site and off-site delivery
On-site delivery is preferred where suitable habitats can be created or enhanced, but it is not always achievable.
Off-site Biodiversity Net Gain can be used where on-site delivery cannot achieve the required improvement due to site constraints, layout, or long-term management considerations.
Yes. Off-site delivery is an intended and accepted part of the Biodiversity Net Gain framework when used appropriately and secured correctly.
Calculating biodiversity units
Biodiversity units are a standardised way of measuring habitat value and change, calculated using the biodiversity metric.
Biodiversity units are calculated using information about habitat type, size, and condition, typically provided through ecological assessment.
No. Calculating the number of units required is about understanding the scale of the requirement, not making a commitment.
Browsing and reserving units
Browsing available units allows you to see what off-site options exist and whether suitable Biodiversity Net Gain units are available, without any obligation.
Reserving units allows availability to be secured while planning decisions are finalised, without formally allocating the units to a development.
No. Reserved units are not formally allocated until the allocation stage is completed.
Allocation and compliance
Allocation usually takes place once planning permission is granted and planning conditions or obligations are ready to be discharged.
Allocated units are formally committed to a development and recorded appropriately, completing Biodiversity Net Gain compliance.
Biodiversity improvements are typically secured for a minimum period, usually 30 years.
Practical considerations
Biodiversity Net Gain does not need to delay planning when it is addressed early and handled through a clear, structured process.
Long-term management arrangements are put in place to ensure habitats are maintained for the required period.
Biodiversity Net Gain must be addressed as part of the planning process and cannot be deferred indefinitely.
Still unsure?
If you are unsure how Biodiversity Net Gain applies to your project, the best place to start is understanding the requirement and the scale of the obligation.
When approached as a clear, step-by-step process, Biodiversity Net Gain becomes a manageable part of development planning.