Think of Biodiversity Net Gain (BNG) units as the missing puzzle piece in your planning application. The one that can unlock approval, safeguard timelines, and support your sustainability goals all in one go.

Whether you're deep into development plans or just starting to scope things out, understanding how to secure BNG units, and when, can make the difference between a smooth sign-off and frustrating delays.

In this blog, we walk you through the process step-by-step, so you know exactly what to expect, what to prepare, and how to make the smartest choice for your site.

Understanding Your BNG Requirements

Before you can purchase units, you need clarity on what’s required of your site. That starts with:

• Ecological Survey: A qualified ecologist will assess your site’s existing habitats and biodiversity value.

• DEFRA Metric Calculations: Using the official DEFRA biodiversity metric, your net gain requirement is calculated based on the proposed development impact.
  

This process will tell you:

• How many BNG units you need

• Whether on-site enhancements are enough — or if you’ll need to purchase off-site units (most likely).
  

On-Site vs. Off-Site Delivery

You’ve got two options when it comes to delivering net gain:

• On-site enhancement: Creating or improving habitats within the red line boundary of your project. This can work well on larger or more flexible sites, but often comes with space, design, or cost limitations; as well as constant upkeep and maintenance. 

• Off-site compensation: when on site delivery isn’t viable, purchasing BNG units from a trusted habitat bank like dragonfly, offers a straightforward, hassle free solution.

Read a more indepth blog on the pro’s and con’s of on-site vs off-site delivery here.

The Step-by-Step Process of Purchasing BNG Units

Step 1: Initial Consultation
Get in touch with us to share your project details and relevant documentation — including your ecological survey and DEFRA metric report. The earlier in your planning journey, the better.

Step 2: Requirement Analysis
We review your documents, confirm your unit requirement, and explore ways to optimise your strategy, including any opportunities to reduce cost or complexity.

Step 3: Proposal & Agreement
You’ll receive a tailored proposal detailing the type, quantity, cost, and availability of units. Once approved, we formalise the agreement,  including any legal fees and contractual terms.

Step 4: Planning Application Support
We provide all the documentation you need to support your application, including:

• A Letter of Reservation

• BNG Solution Methodology / BNG Plan outline

• Habitat Management & Monitoring Plan (if required)
  

Step 5: Post-Approval Actions
Once your planning application is approved, we finalise the purchase agreement. Your units are registered and linked to your site, ensuring full compliance with policy and regulation.

Key Considerations

Proximity Matters
The closer your units are to your development, the lower your spatial risk multiplier, and the more attractive your application may be to planning authorities.

Quality & Credibility
Only buy units from reputable, accredited habitat banks that are fully registered. You need assurance that the habitats are legally secured, properly managed, and ecologically sound.

Start Early
Engaging with a habitat bank early in your timeline helps avoid last-minute pressure and ensures you don’t miss out on availability.

Final Thoughts

Securing BNG units doesn’t have to be complicated. With the right partner (👋 cough cough), it becomes a smart, streamlined part of your planning journey, not a roadblock.

At Dragonfly Habitat Bank, we work closely with developers to deliver high-quality, policy-compliant units that support your goals and boost biodiversity. If you're ready to get started with a trusted partner, we’re ready when you are. Secure your units today.