Biodiversity Net Gain (BNG) Assessments
Get in touchAcorn Ecology provides Biodiversity Net Gain (BNG) Assessments for development projects . The consultancy helps developers, landowners and planning professionals measure biodiversity, meet planning requirements and identify practical habitat enhancement opportunities before construction begins.
What Is Biodiversity Net Gain (BNG) Assessments?
Biodiversity Net Gain (BNG) Assessments measure the ecological value of a site before and after development to demonstrate biodiversity improvements. Acorn Ecology carries out habitat surveys, biodiversity metric calculations and ecological reporting to help projects achieve the required biodiversity outcomes.
Biodiversity Net Gain became a mandatory planning requirement for many developments in England from 2024. Assessments typically use the statutory biodiversity metric to calculate habitat units and identify measures needed to achieve at least a 10% biodiversity net gain where applicable.
What Types of Biodiversity Net Gain (BNG) Assessments Are Available?
Biodiversity Net Gain (BNG) Assessments can support projects of different sizes, from individual housing plots to commercial and infrastructure developments. Acorn Ecology provides surveys and reporting tailored to planning requirements and site conditions.
Baseline Habitat Assessment – Records existing habitats and calculates baseline biodiversity units.
Biodiversity Metric Assessment – Applies the statutory biodiversity metric to measure habitat value.
Habitat Enhancement Plans – Identifies practical on-site habitat improvements where appropriate.
BNG Planning Support – Provides ecological reports for planning submissions.
Post-Development Monitoring Advice – Supports long-term habitat management and monitoring requirements.
When Is Biodiversity Net Gain (BNG) Assessments Needed?
Biodiversity Net Gain (BNG) Assessments are needed before planning decisions are made for many qualifying developments. Acorn Ecology completes assessments early in the design process to reduce delays and allow biodiversity measures to be incorporated efficiently.
Assessments are commonly required for residential developments, commercial schemes, industrial sites, mixed-use projects and land redevelopment. Early ecological input can reduce redesign costs and help planning applications progress more smoothly.
How Does Biodiversity Net Gain (BNG) Assessments Work?
Biodiversity Net Gain (BNG) Assessments follow a structured process that evaluates habitats, calculates biodiversity value and recommends appropriate mitigation or enhancement measures. Acorn Ecology provides clear documentation for planning purposes.
Carry out an ecological site visit and habitat survey.
Record habitat types, condition and distinctiveness.
Complete biodiversity metric calculations.
Identify mitigation, compensation or habitat enhancement opportunities.
Prepare a Biodiversity Net Gain report for planning submission.
Most assessments are completed over several days to a few weeks, depending on site size, habitat complexity and seasonal survey requirements.
Who Needs Biodiversity Net Gain (BNG) Assessments?
Biodiversity Net Gain (BNG) Assessments support clients preparing development proposals that require ecological consideration. Acorn Ecology works with a wide range of sectors throughout and surrounding areas.
Typical clients include:
Property developers
Housebuilders
Architects
Planning consultants
Landowners
Commercial property owners
Local authorities
Infrastructure project teams
How Much Does Biodiversity Net Gain (BNG) Assessments Cost?
Biodiversity Net Gain (BNG) Assessments typically cost from around £900 to £5,000+, depending on the size of the development, habitat complexity and reporting requirements. Acorn Ecology provides quotations based on individual project requirements.
Typical cost ranges include:
Small residential developments: £900–£1,800
Medium-sized developments: £1,800–£3,500
Large or complex sites: £3,500–£5,000+
Costs are influenced by site area, habitat diversity, seasonal survey requirements, biodiversity metric calculations and the scope of ecological reporting.
What Are the Benefits of Biodiversity Net Gain (BNG) Assessments?
Biodiversity Net Gain (BNG) Assessments help developments satisfy planning requirements while improving ecological value. Acorn Ecology provides evidence-based assessments that support informed project decisions.
Benefits include:
Supports planning applications
Measures existing biodiversity accurately
Identifies practical habitat improvements
Helps achieve statutory biodiversity objectives
Reduces planning risks through early ecological advice
Provides clear ecological documentation
What Regulations Apply to Biodiversity Net Gain (BNG) Assessments?
Biodiversity Net Gain (BNG) Assessments are carried out with reference to the Environment Act 2021, which introduced mandatory Biodiversity Net Gain requirements for many developments in England. Assessments typically use the statutory biodiversity metric published by the UK Government and support local planning authority requirements.
Where protected species or designated sites are present, additional ecological surveys may also be required to support planning decisions.
Biodiversity Net Gain (BNG) Assessments: Frequently Asked Questions
How long does a Biodiversity Net Gain (BNG) Assessment take?
A Biodiversity Net Gain (BNG) Assessment typically takes 1 to 4 weeks, depending on the size of the site, habitat complexity, survey season and planning requirements. Larger developments may require additional ecological surveys.
How much does a Biodiversity Net Gain (BNG) Assessment cost?
Costs generally start from around £900 for smaller developments and can exceed £5,000 for larger or more complex sites. A project-specific quotation provides the most accurate pricing.
Is a Biodiversity Net Gain (BNG) Assessment required for every development?
Not every project requires a Biodiversity Net Gain (BNG) Assessment, but many planning applications in England are now subject to mandatory Biodiversity Net Gain requirements. The need depends on the development type and planning legislation.
Can habitat improvements be provided on-site?
Yes. Many developments achieve biodiversity improvements through on-site habitat creation or enhancement. Where this is not practical, alternative solutions may be considered in accordance with planning requirements.
Does a Biodiversity Net Gain (BNG) Assessment include ecological surveys?
Yes. A Biodiversity Net Gain (BNG) Assessment normally includes a habitat survey and biodiversity metric calculations. Additional protected species surveys may also be recommended if habitats indicate they are necessary.
Get a Free Quote for Biodiversity Net Gain (BNG) Assessments
Acorn Ecology provides professional Biodiversity Net Gain (BNG) Assessments for developments. Contact the team to discuss your project and receive a tailored quotation based on your planning requirements.
Related Biodiversity Net Gain (BNG) Assessments Services
BNG calculations often begin with a UKHab habitat condition survey to accurately classify habitats and establish baseline biodiversity value.
Most developments also require a Preliminary Ecological Appraisal to identify ecological opportunities and planning constraints.
Where planning permission is required, an Ecological Impact Assessment can assess the wider environmental effects of the proposal.
Long-term biodiversity improvements are supported through habitat management and enhancement plans, ensuring habitats are maintained after development.
If protected species are present, our protected species surveys provide the ecological evidence required for planning decisions.
We also prepare ecological planning support and survey reports to bring together BNG calculations, habitat assessments and supporting ecological documentation.