BNG commitments are legally enforceable. If a developer doesn't deliver what the Biodiversity Gain Plan promised, the local planning authority has powers to pursue compliance—and for off-site delivery, conservation covenant holders can act independently. This isn't theoretical: the enforcement mechanisms exist and, as BNG beds in, they'll increasingly be used.
That said, enforcement is only as good as the monitoring that detects problems and the institutional capacity to act. Understanding how this actually works—and where the gaps are—matters for developers structuring their BNG delivery and for anyone assessing counterparty risk in off-site arrangements.
BNG obligations are secured through planning conditions and legal agreements. Each creates different enforcement routes.
Planning conditions attach to the permission itself. The biodiversity gain condition requires an approved Gain Plan before development starts, but it also sets expectations for delivery. If a developer doesn't implement the habitat works described in the Gain Plan, that's a breach of condition. LPAs can issue breach of condition notices under section 187A of the Town and Country Planning Act, requiring compliance within a specified period. Non-compliance with a breach of condition notice is a criminal offence.
Section 106 agreements are contracts between the developer and the LPA, binding the land. Breach of a section 106 obligation can be enforced through the courts—the LPA can seek an injunction requiring performance, or damages. Section 106 enforcement is civil rather than criminal, but injunctions are powerful remedies.
Conservation covenants are enforced by the responsible body holding the covenant—Natural England, a local authority, or a qualifying conservation organisation. The responsible body can take court action for breach, including seeking injunctions and damages. Importantly, this enforcement route doesn't depend on LPA resources or priorities: a Wildlife Trust holding a covenant can pursue a defaulting landowner directly.
Enforcement starts with someone noticing there's a problem. For BNG, that means monitoring.
On-site habitats secured through planning conditions or section 106 are the LPA's responsibility to monitor. In practice, monitoring capacity varies enormously between authorities. Some have dedicated ecology officers who track BNG delivery; others are stretched thin and rely on complaints or periodic spot-checks. Government guidance expects LPAs to monitor, but doesn't mandate specific inspection regimes.
Off-site habitats secured by conservation covenants are monitored by the responsible body. These organisations often have stronger conservation focus and may be more proactive about checking whether habitat management is happening. Registration on Natural England's Biodiversity Gain Sites Register creates a paper trail, but the register itself doesn't monitor habitat condition—that depends on the covenant holder.
Problems that might trigger enforcement include:
The further into the 30-year period, the greater the risk that monitoring lapses and problems go unnoticed. A habitat that degrades in year 22 may not be picked up if the responsible party isn't actively checking.
The response to non-compliance typically escalates:
Informal resolution comes first. The LPA or responsible body contacts the landowner, identifies the problem, and agrees a remediation plan. Most issues get resolved at this stage—sometimes it's a misunderstanding, sometimes management has slipped and can be corrected.
Formal notices follow if informal approaches fail. For planning condition breaches, this means breach of condition notices with specified compliance periods. For section 106 or covenant breaches, formal letters before action.
Court proceedings are the backstop. Injunctions can compel specific performance (requiring the landowner to carry out management works) or restrain harmful activities. Damages can compensate for ecological harm, though quantifying biodiversity loss in monetary terms is difficult.
Step-in rights may exist in well-drafted agreements. These allow the LPA or responsible body to enter the land and carry out necessary works, recovering costs from the landowner. This is particularly important where the landowner is unwilling or unable to perform—it means the habitat can still be managed even if the original obligor has defaulted.
Criminal liability applies to breach of condition notices but not generally to section 106 or covenant breaches. However, the threat of injunction—with contempt of court consequences for non-compliance—provides serious leverage.
The enforcement framework looks robust on paper. Whether it works in practice depends on institutional capacity.
Local planning authorities are under significant resource pressure. The Local Government Association has noted that many councils lack sufficient ecological expertise for BNG duties, and enforcement teams are already stretched. Proactively monitoring BNG sites for 30 years, identifying underperformance, and pursuing enforcement is a substantial commitment.
The Royal Town Planning Institute has raised similar concerns about whether current enforcement resources are adequate for the scale of BNG obligations now being created. Every development subject to BNG adds another site to monitor, another set of obligations to track.
This doesn't mean enforcement won't happen—it means it may be reactive rather than proactive, triggered by complaints or obvious failures rather than systematic monitoring. A developer or landowner who quietly neglects habitat management may get away with it for years. But they remain in breach, and enforcement can be triggered at any point during the 30-year period if someone notices.
Conservation covenant holders may be more reliable monitors than LPAs, since conservation is their core purpose. This is one reason why off-site BNG increasingly uses covenants held by environmental organisations rather than relying solely on section 106 enforcement.
For on-site delivery, the risk sits with whoever owns or manages the development site. If habitat management fails, the LPA pursues the current landowner—which might be a management company, housing association, or individual plot owners depending on site structure. Original developers who've sold out may have ongoing liability under section 106 agreements depending on how those are drafted.
For off-site delivery, the risk picture is more complex. The developer's obligation is discharged by purchasing properly secured units—the ongoing liability belongs to the habitat provider. But if the provider fails and the habitat degrades, there's at least reputational risk for the developer, and potentially planning risk if the failure is severe enough to call the original permission into question.
This is why due diligence on off-site providers matters. A habitat bank with inadequate funding, inexperienced management, or weak legal security creates counterparty risk. If the provider defaults, the units allocated to your development may not deliver the biodiversity value they claimed.
EcoCapital structures off-site BNG delivery to minimise enforcement risk on both sides. Units come from habitat banks with conservation covenants held by credible responsible bodies, management plans designed by qualified ecologists, and funding arrangements that cover the full 30-year term.
For developers, this means purchasing units where the enforcement framework actually works—not just in theory but in practice, with active monitoring and responsible bodies motivated to ensure compliance. For the Biodiversity Gain Plan approval, it means demonstrating to the LPA that off-site delivery is genuinely secured, not dependent on providers who may not perform.
