Henry Mills, CEO of Burlingtons Biodiversity Solutions, discusses how mandatory biodiversity net gain rules impacted development planning in the UK by embedding ecological enhancement as a legal priority.
Henry’s article was published in Property Week, 12 February 2025.
Mandatory Biodiversity Net Gain (BNG) has fundamentally reshaped development planning in the UK, embedding ecological enhancement as a legal priority rather than an optional add-on. Developers are now required to approach projects with a dual focus: delivering commercial viability while ensuring measurable biodiversity uplift. This shift has spurred innovation, with developments increasingly featuring wildlife corridors, green roofs, and enhanced habitats that balance urban growth with ecological preservation.
For larger developers, BNG has driven early collaboration with ecologists and landowners, creating a new blueprint for sustainable design. However, smaller developers face a steeper challenge despite the introduction of Defra’s Small Sites Metric (SSM) and simplified templates. These tools help streamline compliance but do not eliminate the complexity of aligning ecological requirements with tight budgets and timelines.
BNG’s greatest impact is in reshaping timelines and priorities. Developers must now build biodiversity strategies into their planning from day one, delaying projects in the short term but fostering long-term benefits for both communities and ecosystems. This cultural shift is pushing the industry toward a more integrated and responsible approach to development.
Furthermore, BNG has not just influenced planning; it has catalysed a rethinking of land use, turning biodiversity from a regulatory hurdle into a central pillar of modern development.
Mandatory Biodiversity Net Gain has sparked a profound shift in how developers approach their projects. No longer is the environment an afterthought; it is now a cornerstone of planning, with developers reimagining urban spaces as ecosystems that benefit both people and wildlife.
One notable example is Mansfield, Nottinghamshire, where, in a groundbreaking £76 million initiative, sustainable drainage systems (SuDS) are transforming neglected green spaces into vibrant biodiverse basins. Rain gardens, permeable pavements, and bioswales are not just controlling floods but are bringing life back to communities—an approach Severn Trent hopes will become the gold standard for urban development.
This transformation goes beyond compliance. Developers are now thinking like ecologists, incorporating green roofs, wildlife corridors, and community-focused green spaces into their designs. This new mindset benefits everyone: residents enjoy healthier, greener neighbourhoods; developers enhance the value and appeal of their projects; and nature itself gets a lifeline in our increasingly urbanized world.
BNG is more than ticking boxes—it is about creating a legacy. It represents a shift toward a future where construction and conservation are no longer at odds, but work together to build better places for all.
Biodiversity Net Gain is a bold step forward, but like any transformative policy, it comes with its challenges. While its intent to harmonise development and ecology is commendable, its execution has exposed breaches that need addressing to ensure long-term success.
One key challenge is the uncertainty surrounding tax implications for biodiversity credit sales. Without clear guidance on whether these fall under income tax or capital gains tax, landowners and developers are left in limbo, hindering confidence and slowing engagement. Clear policies in this area are essential to provide the certainty needed for effective planning and investment.
Geographic limitations also pose a noteworthy hurdle. Natural England’s “distance multiplier” encourages local offsets but often leaves urban developers struggling to find suitable sites nearby. This can result in biodiversity enhancements being disproportionately directed to rural areas, while cities—where green spaces are most needed—may be underserved.
Smaller developers face their own set of challenges. Despite the introduction of tools like Defra’s Small Sites Metric, compliance can still feel overwhelming. Administrative burdens and upfront costs remain significant barriers, creating the risk of a two-tier system where only well-funded firms thrive.
With the right reforms, BNG can transcend its challenges to become a transformative force—rewriting the rulebook on how we balance growth and ecological responsibility.
