Do you need to buy biodiversity net gain units?

A Guide To Buying Biodiversity Net Gain Units

If you need to provide biodiversity net gain units to enable a planning application to proceed, this article explains the available options and the process involved.

What is biodiversity net gain?

The Biodiversity Net Gain (BNG) concept was introduced in the Environment Act 2021 and marked a major change in the UK’s approach to development and nature. The introduction of BNG legislation means that development projects must consider the impact that they will have on nature recovery. All development must ensure that it leaves nature in a measurably better state than it was before. Developments must increase the level of biodiversity on a site by at least 10% on completion and this must be maintained for at least 30 years.

Following a two-year transition period, biodiversity net gain became part of planning law in February 2024. Biodiversity net gain is now part of the National Planning Policy Framework, and compliance with the policy is now an obligatory part of the planning process. To assess biodiversity net gain on a site, a statutory biodiversity metric was immediately introduced, and a biodiversity net gain small sites metric was brought into play in April 2024.

Biodiversity net gain regulations in practice

Local planning authorities will require a BNG plan to accompany planning applications. The plan must convince local authorities that the required amount of biodiversity net gain will be achieved on the site. While the provision of on-site biodiversity net gain is the optimal approach favoured by planning authorities, if an ecological consultant concludes that it is not possible to achieve the required amount of net gain according to the biodiversity gain hierarchy within a site’s red line boundary, other ways of achieving the required biodiversity gains can be investigated. A developer can buy off site biodiversity units, or statutory credits as a last resort.

Buying biodiversity net gain units or credits

Biodiversity offsetting

Biodiversity units can be purchased from habitat banks, which are specially created or restored areas containing valuable habitats designed to be matched to a developer’s requirements. If you are looking to buy BNG units, they can be purchased through various organisations or a specialist third party company. While the price of purchasing biodiversity units varies, they can enable a developer to comply with planning policy. Biodiversity units are viewed as the second-best option following on site gains.

Statutory credits 

A third option is to buy statutory credits. This usually comes into play in situations where it is not possible to provide on site BNG or buy enough off site units. Statutory biodiversity credits allow a developer to buy the required number of credits and funds will be directed at nature recovery schemes such as local nature recovery strategies nationwide. The credits market is regulated by the government, Defra and Natural England, and credits are bought from the government.

How to deliver biodiversity net gain

1. The biodiversity net gain assessment

 On finding that BNG applies to their scheme a developer should instruct a BNG survey. This involves a desk study and assessment of the site’s baseline value for pre development biodiversity. An ecological consultant will compare the site’s current and predicted biodiversity value by using the statutory biodiversity metric. The biodiversity metric creates an ecological value for the site before and after development to establish the gap between the two figures. A BNG plan can be drawn up which will indicate how best to eliminate the gap and add at least 10% increase in biodiversity.

2. On site biodiversity net gain

Retaining and improving a site’s biodiversity value is the optimal way to approach BNG. This may be possible by altering development plans to ensure that existing habitats are retained, and ensuring that any habitat lost is compensated for by new habitat creation. There are numerous ways of increasing biodiversity value, including sustainable development initiatives like green roofs or environmentally valuable planting schemes. In cases where an environmental consultant has explored all possible options using the biodiversity gain hierarchy and cannot find a route to fulfilling the BNG requirements, the next step must be considered.

3. Off-site biodiversity units

BNG units can be purchased from a nearby habitat bank to enable a developer to fulfil the required commitment. This can be done via a private market arrangement or a purchase arranged through a third-party company. This is the second best option, as local habitat is involved despite a gain not being possible on the development site itself. Conservation covenants will need to be drawn up to bind the land managers to comply with the legal obligation to conserve the site and fulfil the BNG target on behalf of the developer. The legal agreement will ensure that the responsible person will manage the site for at least 30 years and ensure biodiversity quality is maintained.

4. Buy statutory credits

This is the last resort option which may be reverted to when on site habitat improvements or off site units fail to deliver the required amount of BNG. There may also be a lack of local habitat bank units available to fulfil a developer’s bng requirements. By referring to the biodiversity net gain plan, which shows the number of biodiversity units needed, the number of biodiversity credits needed can be calculated. For each single unit that must be compensated for, a developer must purchase two credits. Government bodies sell statutory biodiversity credits.

How to buy biodiversity net gain units and credits

BNG units for sale

 A completed biodiversity net gain plan forms part of an application for planning permission and will confirm whether BNG units are needed. Local planning authorities can approve a scheme subject to the requirement to provide the required BNG provisions. The next step is to identify suitable land with net gain units for sale. A third party may be needed to help with this. Once identified, a 10% deposit is paid for the biodiversity units which secures them for four months. The development may proceed, and the remaining 90% cost of the units must then be paid.

BNG credits for sale

The BNG plan will demonstrate that utilising the mitigation hierarchy proved that it was impossible to create the amount of BNG needed on a site. It includes details of the biodiversity units lost during the development and a figure of how many biodiversity credits are needed.

Statutory biodiversity credits can be bought from the government: third-party agents and representatives cannot carry out this function. The application process involves uploading the metric calculation tool onto the government website. Applications must include development site details, project details, the calculated amount of statutory biodiversity credits needed and evidence that on site and off site provision of units is not possible. The government will process applications, and a certificate for the credits will be provided when they are purchased.