Preliminary Ecological Appraisal (PEA)
Desk study and walkover that establishes habitats, constraints, and the proportionate route into UKHab typing and the statutory biodiversity metric.
Learn moreSurveys from £295
Biodiversity Net Gain (BNG)
Mandatory BNG — UKHab baseline, statutory metric and gain plan your LPA signs off before commencement.
Biodiversity Net Gain
If your planning application is for a development in England, Biodiversity Net Gain (BNG) almost certainly applies to you. Since February 2024 it has been a mandatory condition on planning permissions — meaning you cannot lawfully start work until your local planning authority (LPA) has approved a Biodiversity Gain Plan showing at least a 10% uplift in biodiversity value. That applies even if your site has no protected species at all.
The baseline survey that underpins that plan is not a box-ticking exercise. It determines your starting biodiversity value, dictates whether you can meet the 10% target on your own site or need to purchase off-site units, and has to be robust enough to pass scrutiny from your LPA’s ecologist at validation. Getting it right at the start saves you time and cost later.
Does BNG apply to your site?
Not every application is in scope. Householder applications, permitted development rights, and sites below a minimum size threshold are currently exempt. A new exemption raising the area threshold to 0.2 hectares is expected before July 2026, which would remove BNG requirements from many smaller residential permissions. We confirm whether your site is in scope or qualifies for an exemption at the point of instruction, so you are not spending money where it is not needed.
How we work with you
We align BNG fieldwork with your Phase 1 habitat survey wherever possible, keeping your programme efficient and your costs down. The Biodiversity Gain Plan is prepared from your finalised layout — so we need a confirmed red line boundary and, where you have one, a proposed landscape strategy before the plan is completed. If your layout is still evolving, we will advise early on how sensitive your baseline score is to design changes, so you can make informed decisions before the scheme is fixed.
Biodiversity Net Gain — your questions answered
What is the difference between the baseline survey and the Biodiversity Gain Plan?
The baseline establishes habitat types, condition, and the pre-development biodiversity value in the statutory metric. The Biodiversity Gain Plan is a separate requirement: it explains how you will achieve and maintain the minimum 10% uplift after development, how gains will be secured for 30 years, and how delivery will be evidenced — including on-site measures, off-site habitat, or statutory credits where those routes are used.
Your LPA will expect the baseline to be robust at validation; the Gain Plan is what they must approve before you can lawfully commence works in scope.
Can Phase 1 habitat survey and BNG baseline be done in one visit?
Often, yes. Where the scope is aligned, we programme one coordinated field visit so habitat mapping, UKHab typing for the metric, and the PEA narrative stay consistent — avoiding duplicated effort, conflicting habitat lines, and extra access days.
If your site needs additional seasonal species survey, that is scoped separately and sequenced so it does not undermine your baseline.
When should the Biodiversity Gain Plan be prepared?
The Gain Plan should reflect your finalised red line and a clear view of the proposed development — including landscape proposals where they affect habitat delivery. If your layout is still moving, we still advise early on baseline sensitivity so you understand how design choices affect the metric before the scheme is fixed.
We will tell you what we need (for example confirmed boundaries and landscape strategy inputs) before we finalise the plan for submission.
How do I get a fixed price?
Send your site location, red line where you have it, and what stage you are at (pre-application, validation, or discharge). We confirm what is in scope for mandatory BNG, what baseline and plan deliverables you need, and provide a fixed quote with assumptions spelled out in plain language.
BNG deliverables that stand up at validation
Get a free quoteUKHab-typed baseline, metric calculations and a gain plan that makes delivery options clear early — on-site first, off-site or credits where needed.
UKHab baseline survey and metric calculation
Habitat typing, condition assessment and pre-development biodiversity value calculated to the statutory metric, ready for validation.
Biodiversity gain plan
On-site and off-site delivery strategy, management and monitoring obligations, and 30-year securing mechanism.
Combined Phase 1 and BNG survey
Single site visit feeding both your PEA and biodiversity metric, avoiding duplication of fieldwork.
Irreplaceable habitat identification
Ancient woodland, veteran trees and other irreplaceable habitats flagged at baseline so constraints are understood before design is fixed.
Exemption and scope advice
Clear guidance at instruction stage on whether mandatory BNG applies, and how recent policy changes affect your scheme.