Biodiversity Net Gain ('BNG') has significant implications, and genuine opportunities, for landowners and industries that occupy large areas of land over extended periods: quarrying, mineral extraction, landfill, and heavy industrial activity. The instinctive response to a new planning obligation may be to focus on burden. That approach risks missing a considerable opportunity.

BNG requires at least a 10% uplift in biodiversity value over the pre-development baseline and is now a statutory requirement for most new planning permissions in England. That obligation can be met through: 

• Onsite habitat enhancement.
• Offsite biodiversity units (which must be registered and allocated to a development/planning permission). 
• Biodiversity credits.

For those with significant landholdings, this multi-pathway structure creates genuine flexibility: generate and sell offsite biodiversity units on the open market, or bank them against future development requirements.

This article considers:

• Part 1: The commercial and reputational opportunity that using land to create offsite biodiversity units presents; and 
• Part 2: The legal obligations, practical constraints, and long-term liabilities that must be understood before any commitment to the BNG market is made.

A note on NSIPs

Nationally Significant Infrastructure Projects ('NSIPs'), which includes major energy, transport and industrial infrastructure, are currently exempt from mandatory BNG. The government has indicated that BNG will become mandatory for NSIPs in England from 2 November 2026, applying to Development Consent Order applications made on or after that date. Guidance has also been published online.

For operators and landowners in sectors likely to promote or be affected by NSIPs, early engagement with the BNG framework now, including assessing the unit-generating potential of existing landholdings, is sensible preparation.

Part 1: The opportunity

A new revenue stream from land already in your portfolio

‘Registered offsite biodiversity gain’ is habitat enhancement carried out under a conservation covenant or planning obligation and registered on the biodiversity gain site register. A landowner who creates and legally secures such enhancements can sell or allocate the resulting units to developers needing to satisfy their own BNG obligations. 

For operators with legacy landholdings or buffer zones outside the operational footprint, this creates a route to generating income from land that might otherwise represent only a management cost.

Why these sectors are particularly well placed

• Scale: Quarries, landfill sites and industrial facilities typically control far more land than their operational footprint, with buffer zones and peripheral areas often offering genuine ecological potential.
• Restoration obligations: Mineral extraction sites are subject to planning conditions requiring phased restoration and aftercare. Schemes designed with BNG in mind from the outset can be calibrated to maximise unit generation, turning a cost centre into a commercial opportunity - provided additionality rules are complied with.
• Legacy land: Former operational sites may already carry significant ecological value through natural succession; properly surveyed and legally secured, this land can generate units for which there is active market demand.
• ESG and ‘nature-positive’ credentials: A registered biodiversity gain site is a verifiable, legally secured commitment quantified by the statutory biodiversity metric - increasingly attractive to investors, lenders, and supply chain counterparties operating under their own ESG frameworks.

Reducing the cost of your own compliance

Operators with a continuing development programme can also use offsite biodiversity gain as an internal resource, banking biodiversity value from restoration or legacy land and allocating it against future BNG obligations, materially reducing compliance costs across a portfolio.

BNG as a material planning benefit

A genuine biodiversity gain that clearly exceeds the minimum 10%, and is properly distinguished from baseline planning obligations, can be a meaningful factor in tipping a finely balanced planning decision in an operator's favour.

Part 2: The legal obligations and liabilities of entering the BNG market as a supplier

The legal obligations that come with registering land as a biodiversity gain site are significant and long-lasting.

The 30-year binding obligation

Habitat enhancement works must be managed and maintained for at least 30 years after completion, which is a statutory requirement. Land can only be registered as a biodiversity gain site if it is secured by a conservation covenant (for more information, see here) or a planning obligation (s106 agreement) and registered as a local land charge.

These obligations bind the landowner and their successors in title: a future sale will not relieve the commitment. Where land is held on a lease, the ability to satisfy a 30-year management obligation, and any tax implications, must be carefully considered before registration is contemplated.

The registration process is a legal requirement

Registration is required before units can be allocated, and local planning authorities will verify this. Applications must include location and boundary information, habitat baseline data, enforceability details, and allocation information. Registration cannot be done informally or retrospectively, and specialist legal and ecological advice is essential both to achieve registration and throughout the 30-year management period. 

Not all sites are suitable: The ecological reality

Not every parcel of land can generate biodiversity units for which there is market demand, and entering the supply market without proper ecological assessment is a significant risk:

• Baseline ecological value: Gain is calculated as uplift over the pre-enhancement baseline. High-condition land leaves less room for saleable improvement; low-condition land offers greater potential, provided genuine enhancement is achievable and the resulting habitat type has market demand.
• Habitat type and market demand: Units are calculated by reference to habitat type, and buyers frequently require specific types aligned with local nature recovery priorities. Management costs vary considerably, and can be substantial, depending on the habitat created, and must be modelled carefully before entering binding commitments.
• Physical and operational constraints: Former landfill sites may present particular difficulties: residual contamination, methane migration, and ongoing Environment Agency permit obligations can all interact with BNG maintenance commitments in ways that require careful mapping by specialist advisers. Rules about additionality must be very carefully considered.
• Long-term management capability: A credible, properly funded management, monitoring and maintenance plan for 30-plus years is essential. Full-lifecycle costs must be modelled realistically before any commitment is made.

Practical recommendations

• Commission ecological surveys early: Pre-development biodiversity value is the foundation of both BNG compliance and any commercial assessment and confirms whether a BNG habitat bank is ecologically viable.
• Take a strategic view of your wider landholding: Identify restoration and post-operational areas with unit-generating potential before making any commitments.
• Take specialist legal advice before registering any land: The 30-year obligation, conservation covenant mechanics, registration requirements, and interactions with planning conditions, environmental permits and site licences are all complex and affect future land use and value.
• Distinguish BNG benefits from pre-existing obligations: Additionality rules require clarity on whether restoration is required by existing conditions or constitutes genuine additional gain.
• Model the commercial case with full-lifecycle costs: Income from biodiversity units must be weighed against ecological surveys, legal documentation, and 30-plus years of management and monitoring. The case can be compelling, but only if costed realistically.

Conclusion

BNG is a genuine strategic opportunity for land-intensive industries: for operators with significant landholdings, particularly those with restoration obligations or legacy post-operational land, it offers a structured route to generating income, reducing compliance costs, and building a verifiable nature-positive narrative. The legal obligations are substantial, the ecological suitability of individual sites varies widely, and the 30-year commitment demands specialist legal and ecological advice before any step is taken.

We provide expert BNG advice to landowners, developers and local authorities, including in relation to the setting up of BNG habitat banks and negotiating of conservation covenants. 

Browne Jacobson at the ESS Expo 2026

Browne Jacobson is hosting the ESS Environmental Law Theatre at the ESS Expo, taking place at the NEC Birmingham on 16 and 17 September 2026. The two-day programme includes dedicated sessions on biodiversity net gain and natural capital opportunities, alongside a range of broader environmental law issues shaping business today.