How to Find BNG Units Secured via Conservation Covenants

Since biodiversity net gain (BNG) became mandatory in England in 2024, many developers have been legally required to leave project sites in a measurably better state than they found them.¹

Developers of schemes subject to BNG (exemptions are listed on gov.uk)² that cannot achieve the minimum 10% uplift³ on-site can source and buy off-site BNG units to make up the shortfall.

Off-site units can only be used if they are listed on the biodiversity gain sites register.⁴ To be accepted onto the register, units must be legally backed by one of two mechanisms: either a section 106 agreement or a conservation covenant.⁵

Why Do Biodiversity Units Need Legal Protection?

The purpose of biodiversity net gain isn't just to enhance habitats on or close to development sites in England. It aims to uphold any improvements for the long term.

Binding legal commitments from landowners, both current and future, and a responsible third party with enforcement powers ensure that will happen.

Section 106 Agreements

Named after section 106 of the Town and Country Planning Act 1990,⁶ these agreements detail the planning obligations decided between a local planning authority (LPA) and a developer over a particular project.

When it comes to biodiversity units, it is the landowners,⁷ not developers, who enter into an agreement with a habitat's relevant local planning authority.

Landowners planning to enhance or create habitat must supply the LPA with detailed information on the habitat enhancements planned, and can include the specific actions they will take to achieve them. The agreement also sets out who is responsible for creating, enhancing, maintaining and monitoring the habitats. Landowners can provide a detailed schedule of management and monitoring in a habitat management and monitoring plan (HMMP).⁸

The agreement must run for at least 30 years, and that period begins when all habitat enhancement works needed on land under the legal agreement are finished.⁹

Conservation Covenants

Created by Part 7 of the Environment Act 2021,¹⁰ conservation covenants can be used to secure BNG, among other conservation purposes. They offer a private, legally binding¹¹ way to secure biodiversity units with a designated responsible body.

Landowners seeking a conservation covenant must hold the land's freehold title, while leaseholders must have a lease of more than seven years with time remaining on it.¹²

A local authority can act as a responsible body. So can a public body or charity, or a private sector organisation, where at least some of its main purposes, functions or activities relate to conservation.¹³

The responsible body's primary role is to monitor that the landowner meets the covenant's terms on the habitat's creation, enhancement and maintenance. It must also have contingency arrangements in place for any unplanned changes that could affect its management of covenants.¹⁴

The list of designated responsible bodies is published on gov.uk.¹⁵

Like section 106 agreements, conservation covenants used for BNG are a commitment between the landowner and a designated responsible body to create, enhance and maintain habitat for at least 30 years.¹⁶

However, conservation covenant agreements do not override pre-existing statutory rights, obligations, private property rights, planning restrictions or statutory designations.

Land managers should check their legal deeds, land registry title documents and government-funded environmental scheme rules, while tenants should review their rental agreements to ensure there are no obstacles.¹⁷

The Advantages of Conservation Covenants

Section 106 agreements have been used by developers to determine planning obligations for many years. While it's a familiar mechanism, it can be a time-consuming one. Home Builders Federation analysis of Freedom of Information responses from LPAs found that section 106 agreements took an average of 515 days to finalise in 2024/25, although that figure covers planning obligations generally rather than BNG agreements alone.¹⁸

Conservation covenants impose obligations similar to those in a section 106 agreement.¹⁹ Where LPAs are short of resources, they may be a faster alternative, provided a responsible body can be found that is willing to enter into one. That can accelerate the process of registering and selling biodiversity units.

How We Help Landowners Generate BNG Units

Landowners thinking about turning part or all of their land into biodiversity units can be intimidated by the process. Our team can offer support and guidance at every stage, including ensuring the long-term legal security of your BNG units.

We also operate a national network of habitat banks, with all units legally secured and with all the documentation needed for planning submission.

Email us at sales@greenshank-environmental.com or fill in this contact form and we'll be in touch as soon as possible.