How to Complete a Biodiversity Gain Plan: Step-by-Step Guide
As Biodiversity Net Gain beds into the planning system, one document is becoming central to almost every development project: the Biodiversity Gain Plan (BGP).
In this short video, Jen Stott, Operations Manager at Biodiversity Units UK, walks through the Biodiversity Gain Plan template section by section and explains how to complete it in a way that satisfies your local planning authority and clearly demonstrates your 10 percent net gain. This blog sits alongside that explainer as a written step-by-step guide.
If you would rather not wrestle with the detail yourself, Biodiversity Units UK can also prepare the Biodiversity Gain Plan for you as part of our BNG Certainty Service.
What is the Biodiversity Gain Plan is trying to do?
Before jumping into the form, it helps to keep the purpose in mind.
The Biodiversity Gain Plan is there to:
Show what habitats exist on your site before development
Set out the habitats and enhancements that will be delivered after development
Evidence that the overall change delivers at least 10 percent Biodiversity Net Gain using the approved metric
Confirm how those gains will be managed and monitored for at least 30 years
Everything in the template is pulling together information you probably already have in planning documents and ecology reports. The BGP simply packages it in a standard format that planning officers can understand and sign off.
Step 1:
Project and site details
The opening part of the template is straightforward but important. Here you will typically include:
Basic project details (site name, address, planning reference)
Applicant and consultant contact details
A short description of the proposed development
Keep this section clear and consistent with your planning application. It is effectively the front cover for the more technical information that follows.
Step 2:
Baseline habitats and existing conditions
Next, the plan asks you to describe what is on the site now. This is where you:
Summarise the existing habitats identified in the ecological surveys
Cross-reference the baseline DEFRA Biodiversity Metric
Highlight any sensitive or priority habitats
You do not need to repeat full survey reports here. Think of this section as the headline story of the baseline: what you start with before anything is built.
Step 3:
Proposed development and on-site measures
The template then moves on to what will change as a result of the development and how you will respond to those impacts.
This is where you:
Describe the main physical changes to the site (buildings, access, hardstanding, layout)
Identify which existing habitats will be lost or modified
Set out the on-site enhancement measures you will deliver, for example:
Wildflower grassland creation
Woodland or scrub planting
Hedgerow enhancements
Green corridors and connected habitat routes through the site
The aim is to show that the development and nature have been designed together, not in isolation.
Step 4:
Metric results and headline numbers
The BGP will then refer directly to the Biodiversity Metric calculation that sits behind the plan.
In this section you summarise:
Baseline units on the site
Post-development units created on site
Any off-site units purchased, if applicable
The final percentage net gain
Planning officers do not need every cell from the spreadsheet here, but they do need to see a clear line of sight from the numbers in the metric to the story in the plan.
Screenshots or simple tables can be useful.
If you work with Biodiversity Units UK, our team ensures that your Biodiversity Gain Plan and metric are fully aligned so there are no surprises or mismatches at determination stage.
Step 5:
Off-site biodiversity units (if required)
If your project cannot reach the full 10 percent net gain on site, the template includes a section for off-site biodiversity units.
Here you will typically set out:
How many units are being delivered off-site
The habitat types and location of those units
The delivery mechanism (for example, conservation covenant or section 106)
How the off-site units link back into the metric calculation
This is where Biodiversity Units UK often comes in.
Through our national network of Habitat Banks, we can source and secure the right off-site units for your project and ensure the details are clearly captured in the BGP.
Step 6:
Habitat management and monitoring
BNG is not just about creating habitats, it is about keeping them in good condition over the long term.
The Biodiversity Gain Plan includes space to set out:
The management approach for each habitat type
Who is responsible for management and monitoring
The length of commitment (normally at least 30 years)
How performance will be checked and reported
This section should align with any management plans, legal agreements and funding mechanisms you already have in place.
Step 7:
Sign-off and compliance
Finally, the template will ask you to confirm that:
The information provided is accurate
The development will deliver at least 10 percent Biodiversity Net Gain
The measures described can be secured and implemented
This is what gives the planning authority the confidence to discharge your BNG condition and allow the project to move forward.
How Biodiversity Units UK can help
For many teams, the challenge is not understanding why Biodiversity Net Gain matters, but finding the time and expertise to pull all the information together in the right format.
Through our BNG Certainty Service, Biodiversity Units UK can:
Prepare the Biodiversity Gain Plan on your behalf
Complete or review the biodiversity metric
Source and secure off-site units where needed
Liaise with the local planning authority to resolve queries
In other words, we handle the detail so you can keep your project moving, with confidence that your BNG obligations are properly addressed.