Biodiversity Net Gain: How Planning Teams And Developers Are Making It Work

With the UN Climate Change Conference, COP30, underway in Belém, Brazil, biodiversity and nature conservation is high on the global agenda. And in England, Biodiversity Net Gain (BNG) is an example of how policy is supporting private sector action to improve and restore natural habitats – reshaping how development and nature interact – and it might form the blueprint for other mandatory nature restoration and stewardship market mechanisms that may work around the world.

Now 18 months on from BNG being introduced in England, there has been a great deal of experience gained through the implementation process. Stakeholders have tackled baseline assessments, conservation covenants, habitat banks and biodiversity gain plans. Recent government consultations are evolving BNG further, supporting SME developers and informing the policy's application to nationally significant infrastructure projects.

In this article, we move beyond BNG basics to explore how planning teams and developers are putting BNG into practice from a design, management and maintenance perspective, the common challenges, and the practical steps helping them move from policy to delivery.

BNG policy in planning decisions

Since February 2024, when BNG became mandatory, developers and local planning authorities have been working to ensure compliance with its requirements. The policy asks developers to improve biodiversity by at least 10% on new developments and maintain those improvements for 30 years. But delivering that in the real world is not always straightforward.

Planning teams are balancing environmental goals with the realities of site constraints and development demand. In many cases, developers are looking to improve existing or create new habitats on-site. But when space is limited or the site isn't suitable, off-site solutions come into play. The focus is on reducing harm, making the most of what's possible on-site, and ensuring any off-site habitats are robust and well-managed.

Why early planning matters for BNG

Early engagement between developers (and their professional teams) and local planning authority officers around BNG is proving essential to avoid delays and design conflicts. Those who factor biodiversity into their plans before finalising layouts are likely to see a smoother approvals process with fewer last-minute changes.

Planning teams are supporting this shift by updating local requirements, hosting developer forums, and encouraging the use of standard templates for BNG plans and Habitat Management and Monitoring Plans (HMMPs). These tools help clarify expectations and reduce confusion and cost, especially for smaller developers who may be less familiar with the rules.

Early cost planning is now a key part of the process, with developers starting cost appraisals for creating and maintaining habitats over time to help them decide what's realistic; and avoid passing high costs on to future residents and occupiers through service charges and estate charges.

Throughout the design and planning stage, collaboration is key and means working with a wide range of stakeholders – from the local planning authority and legal advisers to professionals such as ecologists, landscape designers and stewardship specialists. This provides a basis for a more robust plan for BNG as part of development applications and ensures long-term maintenance and success of the natural habitats created.

On-site or off-site BNG? Finding the right fit

Delivering biodiversity improvements on-site is the preferred approach under BNG policy, but it's not always practical, as some habitats require more space or specialist care, and certain sites simply aren't suitable. Developers are expected to demonstrate that they've fully explored on-site options before turning to off-site solutions, such as habitat banks: areas of land managed by specialists, where biodiversity units can be purchased to meet planning requirements.

This blended approach is becoming increasingly common, with simpler habitats – often for smaller scale developments – delivered on-site and more complex ones handled off-site. It offers a practical way to meet biodiversity goals without placing undue pressure on residents or long-term management teams.

BNG long-term care and cost: what matters most?

BNG goes beyond simply creating habitats, it requires developers to look after biodiversity improvements for 30 years. That long-term commitment raises important questions about who will manage these spaces, how much it will cost, and how long term users of the development site will interact with the habitats.

We expect planning officers to look more closely at proposals that could lead to high maintenance costs or are more likely to fail (through a lack of maintenance or because they are less resilient to climate change – drought for example), recognising that if a habitat is expensive to manage and the burden falls on future occupants, it may not be the best option.

There is also the question of how habitat improvements are perceived. Features like wildflower meadows or native shrubs, while ecologically valuable, may need to be balanced with other stakeholder needs and provide an element of useable and aesthetically appealing spaces – nature is not always pretty to all of us.

Developers and planners are finding that clear communication, thoughtful design, and well-placed signage can help residents understand the purpose of these areas and reduce the risk of complaints.

How is BNG monitored and enforced?

Given the long-term commitment to maintaining natural habitats, local planning authorities are putting systems in place to monitor progress and ensure compliance with HMMPs.

While the real test will come years from now, when the first schemes reach maturity – or when new habitats start to fail - the current focus is on building strong foundations and helping developers understand their responsibilities from the outset.

The growing market for habitat banks and biodiversity units

As demand for flexible BNG solutions grows, the market for off-site biodiversity units is expanding rapidly. Habitat banks now give developers a reliable way to meet BNG requirements, with long-term management plans and legal protections built in.

Buying units from habitat banks is becoming a quicker and more predictable process – terms are becoming more standardised, more balanced between buyer and seller, and habitat banks are open to sensible discussions on changes

BNG support for smaller developers

BNG presents unique challenges for smaller developers, who often have less space, tighter budgets, and limited in-house expertise. In response, planning authorities are offering clearer guidance, simpler templates, and more flexible validation processes.

There's also growing interest in adjusting the rules to make things easier for small sites – with proposals being considered as part of the government consultation for minor, medium and brownfield developments. Ideas include raising the thresholds for mandatory BNG, removing extra requirements for off-site delivery, and refining exemptions. These changes aim to uphold biodiversity goals while recognising the practical realities of smaller developments.

COP30 and BNG: local action, global impact

As COP30 highlights global biodiversity and climate resilience among a range of thematic areas on its agenda, the UK's BNG policy in England offers a practical example of local action making a real difference. While there's still work to do, the sector is shifting from policy to delivery - building partnerships, refining processes, and learning from experience along the way.

BNG is more than a planning requirement, it's a chance to integrate nature into everyday places and support long-term environmental recovery. The lessons being learned now will influence how BNG develops over time, where the principles might be applicable to other sectors potentially such as food, clothing and textiles, where land use is key, and how it aligns with global biodiversity goals.

Five practical steps for developers

To meet BNG requirements confidently, developers should:

• Plan early: Factor biodiversity into site design from the beginning and work collaboratively.
• Use standard templates: Natural England's templates can help meet validation requirements for planning applications.
• Think long-term: Consider who will manage habitats and how costs will be covered.
• Be realistic: Deliver what's possible on-site and explore off-site options when needed.
• Stay informed: Keep up with policy updates and local planning guidance.

This article builds on key insights shared during our recent webinar 'Designing with Nature', which brought our legal experts together with a local authority Planning Manager and Land Management specialist to discuss how BNG is being delivered in practice. If you're navigating BNG on live projects, this panel session offers practical reflections on what's working, what's changing, and where collaboration is making a difference.

Read the original article on GowlingWLG.com

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