Biodiversity Net Gain represents a significant shift in how development interacts with the natural environment. Introduced through the Environment Act, biodiversity net gain legislation requires most new development in England to deliver a minimum ten per cent increase in biodiversity value, measured using a statutory biodiversity metric.
While biodiversity net gain requirements are often viewed as a planning obligation, the benefits extend far beyond regulatory compliance. When implemented effectively, BNG delivers multifunctional benefits ranging from enhanced urban green spaces to flood mitigation, improved air and water quality, and stronger local communities. This article explains some of many biodiversity net gain benefits, with a particular focus on urban environments and flood risk reduction.
Biodiversity net gain and the planning framework
Biodiversity net gain, often referred to as BNG, is now embedded within the planning framework and applies to most planning applications granted planning permission in England. The UK Government’s official guidance on biodiversity net gain sets out how developments must assess biodiversity loss, calculate biodiversity units and demonstrate net gain through a biodiversity gain plan.
Local planning authorities are responsible for ensuring BNG requirements are met, with decision-making increasingly aligned to local nature recovery strategies. This integration ensures biodiversity enhancement contributes to wider environmental objectives rather than being treated as a standalone requirement.
Enhancing urban biodiversity and green spaces
In urban settings, inherent space constraints often limit access to natural habitats. Biodiversity net gain helps address this by embedding green infrastructure into new development and regeneration projects. Measures such as species-rich grassland creation and planting of native scrub, green roofs, street trees increase biodiversity value while improving the quality of life for local communities.
Enhancing urban biodiversity supports nature recovery and protects existing habitats that might otherwise be lost to development. These improvements deliver recreational benefits, create healthier living environments and strengthen connections between people and nature in dense urban areas.
Flood reduction through nature-based solutions
One of the most significant biodiversity net gain benefits is its contribution to flood risk management. Climate change has increased pressure on urban flood risk management systems, particularly where natural waterways have been constrained or replaced by hard infrastructure.
BNG encourages the use of nature-based solutions such as natural flood management, sustainable drainage systems, blue infrastructure and habitat creation. These approaches slow surface water runoff, improve water infiltration and reduce flood risk at a development site and downstream.
The Environment Agency has emphasised the role of biodiversity net gain in recognising and enhancing watercourse and wetland habitats, aligning BNG with its goals for protecting and improving the water environment as part of its natural environment and flood risk work (see The Environment Agency’s role in Biodiversity Net Gain). Natural England alongside partners, has developed tools such as the Environmental Benefits for Nature Tool to support the integration of wider ecosystem services outcomes—including flood management and water quality—into habitat creation and enhancement associated with biodiversity net gain.
Supporting local communities and the local economy
Biodiversity net gain delivers clear social and economic benefits alongside environmental gains. Well-designed green infrastructure improves air quality, supports mental and physical wellbeing and provides accessible spaces for recreation.
Investment in biodiversity enhancement also supports the local economy by creating green jobs linked to land management, habitat monitoring and long-term maintenance. Research from the Grantham Research Institute at the London School of Economics highlights how England’s Biodiversity Net Gain framework could be better aligned with insurance underwriting and urban flood risk management, recognising the role that habitat enhancement and natural flood management can play in reducing long-term flood risk and supporting collaboration between developers, local authorities and the insurance sector.
Reducing biodiversity loss and protecting ecosystems
At its core, biodiversity net gain addresses the persistent challenges of biodiversity loss caused by development. By requiring measurable net gain, the BNG system ensures that development contributes positively to ecosystems rather than simply minimising harm.
Using the statutory biodiversity metric, developers or the ecologists that they work with must assess existing habitats, calculate biodiversity impacts and demonstrate how biodiversity will be created or enhanced. This evidence-based approach supports transparent decision-making and and long-term monitoring.
Why early planning and local context matter
Achieving biodiversity net gain is most effective when embedded early in project design. By understanding the local context, existing habitats and planning requirements from the outset, developers can make informed decisions about retaining and enhancing onsite features while also recognising where well-planned offsite units may deliver greater strategic value — for example, at a larger scale, within Local Nature Recovery Strategy areas, and created specifically to maximise long-term biodiversity outcomes.
Early integration reduces reliance on off-site compensation, improves outcomes for local nature recovery strategies and increases the likelihood of a smooth planning process.
Conclusion
Biodiversity net gain offers far-reaching benefits that extend well beyond compliance. From enhancing urban green spaces and improving air quality to delivering flood reduction and supporting local communities, BNG represents a powerful tool for sustainable development.
For developers, landowners and planners seeking to unlock the full value of biodiversity net gain, Civity provides expert support across strategy, assessment and implementation. Their team helps clients achieve biodiversity net gain in a way that aligns with planning requirements, local priorities and long-term environmental benefits.
Disclaimer
This article is intended as general guidance only and reflects biodiversity net gain legislation and UK government guidance at the time of writing. Requirements and interpretation may vary depending on development type, location and local planning authority policy. Professional ecological and planning advice should always be sought before making decisions.
