Biodiversity Net Gain
Effective Biodiversity Net Gain delivery is determined at the earliest stages of scheme design.
By working with you from the outset, we can reduce the need for additional Biodiversity Net Gain (BNG) units and support a cost-effective approach. Actions taken before baseline assessment, including habitat clearance, can negatively affect unit calculations and lead to increased mitigation requirements.
Our team clarifies what is required, when it is needed and how it integrates with your wider scheme, keeping progress proactive rather than reactive. The result is a thorough, evidence-led report that stands up to local planning authorities and supports approval at first submission.
What Biodiversity Survey Do I Need?
A Quick Guide
The majority of planning applications trigger formal Biodiversity Net Gain requirements.
Use the guide below to match your site conditions to the survey most likely to apply.
Biodiversity Net Gain (BNG) Assessment
When: development must achieve or evidence ≥ 10 % gain.
Purpose: quantify ecological change and define uplift routes.
Timing: baseline year-round.
Biodiversity Gain Plan
When: after baseline/BNG assessment, once layout and habitat proposals are broadly fixed.
Purpose: set out how required BNG units will be delivered, managed and secured.
Timing: usually post-permission, pre-commencement to discharge BNG conditions.
Biodiversity Enhancement Plans
When: where planning policy or a planning condition requires biodiversity improvements as part of the development.
Purpose: explain what ecological enhancements will be delivered, how they will be put in place and how they will be maintained over time.
Timing: usually submitted with the planning application or approved by condition before development begins.
Habitat Management and Monitoring Plan (HMMP)
When: once BGP or BNG strategy is agreed and habitats are defined.
Purpose: detail how habitats will be managed, monitored and reported on for a duration of 30 years.
Timing: typically required alongside or shortly after the BGP for condition discharge.
Your Next Step
Do you require a BNG assessment, or related service? Call us today to book in one of our licenced ecologists.
Biodiversity FAQs
What is Biodiversity Net Gain in planning?
Biodiversity Net Gain (BNG) is a statutory planning requirement in England that requires most developments to deliver at least a 10% increase in biodiversity value compared to the site’s baseline condition. It is measured using the Government’s Biodiversity Metric and must be secured for a minimum of 30 years through approved habitat creation or enhancement.
When does Biodiversity Net Gain apply to a development?
Biodiversity Net Gain applies to most planning applications submitted under the Town and Country Planning Act in England. The requirement is triggered at the point of planning permission and must account for all habitats affected by the proposal, including distinct habitat types and their condition. A Biodiversity Gain Plan must then be approved before development can lawfully commence.
What are Biodiversity Net Gain requirements?
Developers must demonstrate a minimum 10% net gain in biodiversity units compared to the pre-development baseline. This requires a metric calculation, clear habitat proposals and a secured management commitment for at least 30 years. The gain must follow the statutory mitigation hierarchy and be formally approved by the local planning authority.
What is the Biodiversity Net Gain metric?
The Biodiversity Metric is a standardised calculation tool published by the Government. It measures the biodiversity value of a site based on habitat type, condition, distinctiveness and area. The metric is used to quantify losses and gains in biodiversity units and determine whether the 10% requirement has been achieved.
What are Biodiversity Net Gain units?
BNG units are the quantified measure of biodiversity value calculated using the Biodiversity Metric. They represent the ecological value of habitats before and after development. Planning approval requires the post-development unit total to exceed the baseline by at least 10%.
What is a Biodiversity Gain Plan (BGP)?
A Biodiversity Gain Plan is the formal document submitted to the local planning authority to demonstrate how a development will achieve the required 10% biodiversity net gain. It sets out the baseline metric calculation, proposed habitat delivery, and how gains will be secured for at least 30 years. Development cannot lawfully commence until the Biodiversity Gain Plan has been approved.
What is a Habitat Management and Monitoring Plan (HMMP)?
A Habitat Management and Monitoring Plan outlines how newly created or enhanced habitats will be established, maintained and monitored over the required 30-year period. It defines management actions, performance indicators and reporting intervals to ensure biodiversity gains are delivered in practice, not just on paper.
What is a Biodiversity Enhancement Plan?
A Biodiversity Enhancement Plan sets out practical measures to improve ecological value within a site. On smaller developments or where full BNG does not apply, it may be required as a planning condition. The plan focuses on achievable, site-specific enhancements such as habitat creation, native planting or integrated features for protected species.
What are Biodiversity Net Gain exemptions?
Certain developments are exempt, including householder applications, some self-build projects, and sites impacting very small areas of habitat below defined thresholds. However, exemptions are specific and should be confirmed early, as most standard development proposals remain subject to BNG.
What happens if Biodiversity Net Gain cannot be achieved on site?
If sufficient biodiversity gain cannot be delivered within the red line boundary, off-site biodiversity units can be secured from an approved provider. These units must be formally allocated and legally secured before development proceeds. Statutory credits are available only where on-site and off-site options are not feasible.