Biodiversity Net Gain (BNG) will be mandatory for most developments in England, with a phased introduction starting in November 2023. Developments will need to deliver at least a 10% uplift in biodiversity compared to the impacts to habitats within their site boundaries. Habitats must be replaced on a ‘like for like’ or ‘like for better’ principle. Where BNG cannot be delivered on the site, developers can buy biodiversity units on the off-site market.
Baseline survey and working out which habitats to create or enhance
Landowners can create or enhance habitats to sell biodiversity units. The first step is to carry out a baseline habitat survey to determine what habitats are present on their land and what condition they are in.
Landowners can then decide what habitats they want to create or enhance. They may agree to create or enhance certain habitats to sell the units to a specific development, or they may create habitats and sell the units to a developer later (known as habitat banking).
The habitat baseline and planned enhancements for the site can be entered into the biodiversity metric, which uses habitat features to calculate a biodiversity value, to give landowners an idea of unit outputs.
The number of units generated will vary depending on the timing of the habitat creation and the location of the development they are sold to.
Legally securing the land
To sell units, landowners will need to commit to creating and managing habitats for at least 30 years under a legal agreement. This legal agreement must be either a planning obligation (section 106 agreement) with their local planning authority, or a conservation covenant agreement with a responsible body.
Landowners will also need to agree a habitat management and monitoring plan that sets out how they intend to achieve the planned habitat enhancements. A list of responsible bodies, which are needed for landowners to enter a conservation covenant, will be published shortly.
Registering the land
When land has been legally secured, landowners will need to register their land on the Biodiversity Gain Site Register. This will be a digital service where landowners will supply information about their land and planned habitat enhancements. Once approved, information for biodiversity gain sites in the register will be publicly searchable.
Landowners who already have an agreement with developers will have the option to apply to register land and link specific biodiversity units to a development at the same time. The register will become available when BNG becomes mandatory.
Selling biodiversity units
Landowners who are habitat banking will then need to agree to sell units to developers. Developers will have to purchase units for the habitat types that they have impacted. The cost of units must cover the costs of creating or enhancing the habitat, any necessary monitoring and maintaining it for a minimum of 30 years.
Registering units and linking them to a development
After agreeing the sale, the register will need to record the development to which the biodiversity gains are allocated. Local planning authorities will check that developments have the correct allocations before approving their biodiversity gain plan. Once approved, their development can commence.
Habitat creation, enhancement and ongoing management
If habitat creation has not yet started, work to create habitats or enhance existing habitats can begin. Any habitats will then need to be managed and monitored for at least 30 years in line with the legal agreement and agreed habitat management and monitoring plan.