Biodiversity Net Gain
Creating Biodiversity-Rich Developments That Comply With Legislation and Go Beyond
At EMEC Ecology, we help developers achieve Biodiversity Net Gain (BNG)—a planning requirement that ensures new developments leave biodiversity in a measurably better state than before.
In February 2024, the UK introduced landmark legislation requiring a mandatory 10% Biodiversity Net Gain for new developments. This marked a significant advancement in the country’s efforts to protect and enhance natural habitats. As a result, Biodiversity Net Gain (BNG) Assessment, have become essential for developers, businesses, and organisations aiming to meet these legal obligations while promoting responsible environmental management.
What is Biodiversity Net Gain?
Biodiversity Net Gain is an approach to development that leaves the natural environment in a better state than it was before. It is a national planning policy objective, made mandatory by the Environment Act 2021, requiring:
- A minimum 10% increase in biodiversity units
- Delivery of gains either on site, or off-site if onsite is not possible
- A clear, measurable methodology using approved biodiversity metrics
- Long-term maintenance and monitoring for a minimum of 30 years
BNG is now a legal requirement for most major developments and will be extended to smaller sites and Nationally Significant Infrastructure Projects (NSIPs) in 2024 and 2026, respectively. Some Local Planning Authorities (LPAs) have even higher local requirements, making early and expert advice essential.

EMEC’s Expertise in Biodiversity Impact Assessments
We undertake Biodiversity Net Gain (BNG) Assessments in line with national regulations and best practice. These assessments compare the biodiversity value of a site before and after development to determine compliance with BNG objectives.
Our services include:
- Baseline data collection, including Preliminary Ecological Appraisal, UKHab habitat classification and habitat condition assessments using statutory criteria
- Modular River Physical Survey (MoRPH) to assess condition of watercourses where required
- Mapping of habitat type and condition using QGIS to calculate the areas of habitat parcels
- Data input into the DEFRA statutory biodiversity metric or Small Sites Metric
- Calculation of baseline and post-development biodiversity units and % net gain or loss
- Design advice to achieve the required net gain on site wherever possible
- Advice for next steps where net gain is not feasible on site
- Practical, deliverable solutions that align with 30-year BNG commitments
- Avoidance of costly delays by ensuring realistic and achievable schemes
The optimum time to carry out UKHab surveys is typically between April and October. However, survey timings may need to be adjusted depending on the habitat type—for example, woodland flora is best assessed in the spring when key indicator species are most visible. This is where engaging with our ecologists at an early stage is invaluable, as we can help you plan your development effectively and avoid costly delays, ultimately saving you time and money.
Supporting Developers Beyond the Assessment
BNG doesn’t end with planning permission. EMEC offers a full lifecycle solution to help clients implement and maintain biodiversity gains over the long term.
We can:
- Advise on off-site habitat creation to meet biodiversity unit shortfalls on site
- Enhance or create habitats with our in-house land management team
- Develop and deliver 30-year ecological management plans
- Monitor progress and report compliance over the lifetime of a scheme
- Project manage the entire BNG process from start to finish
Why Choose EMEC?
With decades of ecological consultancy experience, EMEC provides a joined-up, cost-effective, and regulation-compliant service. We work closely with developers, planners, and landscape architects to deliver successful outcomes that enhance biodiversity and unlock planning permissions.
Get in touch today to discuss how we can support your project with Biodiversity Net Gain solutions tailored to your site and planning obligations.