Biodiversity Net Gain (BNG) is becoming a fundamental requirement for developers, ensuring that projects leave the environment in a measurably better state than before. A key decision when implementing BNG is whether to achieve it on-site, within the development boundary, or off-site, by enhancing habitats elsewhere. Each approach has its own advantages, challenges, and compliance considerations.

In this blog, we break down the differences between on-site and off-site BNG developments and help you determine the best route for your upcoming project or development.

What is BNG?

Biodiversity Net Gain (BNG) is a planning policy requirement designed to ensure that development projects enhance biodiversity by at least 10% compared to pre-development conditions. It involves creating, restoring, or improving natural habitats to compensate for the ecological impact of construction.

With the UK government’s Environment Act 2021 making BNG a mandatory requirement for most developments, understanding how to achieve compliance efficiently is essential.

On-site vs Off-site BNG: What’s the Difference?

On-site BNG

On-site BNG means implementing biodiversity improvements within the development site itself. This could involve:

• Creating green spaces such as ponds, wildflower meadows, and woodland areas.

• Installing green roofs and walls to support urban biodiversity.

• Enhancing landscaping to support pollinators and local wildlife.

Pros of On-site BNG:

✅ Demonstrates commitment to sustainability within the development.

✅ Can enhance the aesthetic and commercial value of the site.

✅ Immediate access for developers and residents.

Challenges of On-site BNG:

❌ Space constraints may limit habitat creation.

❌ Long-term management of 30 years and high maintenance costs.

❌ May not always be sufficient to meet the 10% BNG requirement.

Off-site BNG

Off-site BNG involves creating or restoring habitats in a different location to offset biodiversity losses from development. This can be done through:

• Investing in habitat banks managed by conservation specialists.

• Partnering with landowners to enhance local ecosystems.

• Supporting large-scale restoration projects to deliver measurable gains.

Pros of Off-site BNG:

✅ Allows for large-scale, high-quality habitat creation.

✅ Managed by specialists, like Dragonfly Habitat Bank, ensuring long-term success.

✅ Ideal for developments with limited space for on-site enhancements.

Challenges of Off-site BNG:

❌ May be located away from the development site.

❌ Requires collaboration with third parties or habitat banks.

Which Approach is Best for Your Project?

The best approach depends on several factors, including:

• Project size & location: Urban developments with space constraints may struggle to meet BNG targets on-site, making off-site solutions more viable.

• Long-term management: Off-site solutions ensure professional habitat management without placing the responsibility on developers.

• Planning requirements: Local authorities may favour a blended approach, using both on-site enhancements and off-site habitat banking to maximise biodiversity impact.

• At Dragonfly Habitat Bank, we specialise in delivering off-site BNG solutions that provide measurable, high-quality biodiversity gains while ensuring compliance with regulatory frameworks.

Choosing between on-site and off-site BNG is a critical decision for developers navigating biodiversity regulations. While on-site enhancements integrate sustainability within the development, off-site solutions offer scale, flexibility, and long-term ecological impact. Often, a hybrid approach that combines both strategies works best.

If you’re looking for a seamless, compliant off-site BNG solution, Dragonfly Habitat Bank can help. Contact us today to explore how we can support your development’s biodiversity goals.