Biodiversity Net Gain and Boundary Design: How Fencing can Support BNG Objectives

When considering Biodiversity Net Gain, fencing is rarely the first feature associated with biodiversity enhancement. More commonly, boundary systems are viewed as a practical requirement that can fragment habitats and restrict wildlife movement. But with the right specification, fencing can help create wildlife corridors, protect sensitive habitats and support long-term ecological management on site.

As biodiversity becomes an increasingly important consideration in development, developers are reassessing the role every site element can play. Since 1970, the UK's wildlife populations have fallen by an average of 19%, with almost one in six species at risk of extinction and less than half of the country's original biodiversity remaining.

To help address biodiversity loss, Biodiversity Net Gain (BNG) is now mandatory under Schedule 7A of the Town and Country Planning Act 1990. The legislation requires most developments in England to deliver a minimum of 10% increase in biodiversity, encouraging developers to look beyond traditional habitat creation measures and consider how wider site infrastructure can support these objectives.

The BNG value of a fencing system can be significantly enhanced through simple design considerations. Traditionally, fencing can create barriers that restrict the movement of small mammals. Solutions such as the  DuraPost® Hedgehog Hole make it easy to create wildlife corridors, often referred to as “hedgehog highways”, enabling small animals to move safely between gardens and green spaces and supporting natural foraging and migration routes.

Another way to boost the biodiversity value of boundary systems is using living fences. Where hedgerows are not a viable option, DuraPost® trellis panels can support native climbing plants, creating green boundaries that delivery similar ecological benefits. These structures provide a sheltered habitat for small animals and aid in increasing biodiversity across the site whilst maintaining a secure boundary. 

For larger species such as deer, well-designed boundary systems can help prevent access to roads and other high-risk areas within a development. Fencing heights of 1.8m or above are often required to deter larger mammals, while durable boundary solutions help create safer, more effective wildlife management corridors. For projects requiring taller boundaries, systems such as the DuraPost® HD and Commercial steel fence posts are available in up to a 5m length.

Fencing is not only used to manage wildlife movement but can also support long-term habitat restorations that require protection from trampling, over-grazing and other disturbances. Strong fencing can be used to exclude grazing animals and reduce pressure on regenerating vegetation, allowing ecosystems to heal.

Noise pollution can have a significant impact on wildlife, particularly where developments are located close to sensitive habitats. Acoustic boundary systems, like Birkdale Sound Shield Pro®, help mitigate this by reducing noise disturbances beyond the site boundary, creating a less disruptive environment for nearby species. Although these solutions do not generate BNG units, they can complement wider biodiversity objectives by helping wildlife thrive alongside new developments.  

While much attention is placed on achieving BNG targets at the planning and construction stages, ongoing site maintenance also plays an important role in protecting biodiversity. Regular repair and maintenance activities can disturb wildlife and habitats, particularly within established ecological areas. Choosing long-lasting steel fence post systems that require minimal upkeep can help reduce these disruptions, supporting healthier ecosystems over the lifetime of the development. 

Creating biodiversity-positive boundaries starts with the right specification. Birkdale works with developers, architects and contractors to deliver solutions that balance ecological benefits with performance and durability. From integrated hedgehog highways and trellis systems, paired with long-lasting DuraPost® steel fence posts, these solutions support biodiversity goals while minimising long-term maintenance and habitat disturbances.  

Planning a BNG-compliant development? Birkdale’s Commercial Specification team can advise on wildlife-friendly boundary solutions, durable steel post systems and fencing designs that balance biodiversity objectives with long-term performance.  

Commercialprojects@birkdalesales.com