The government has published a response to its technical consultation on the use of the new biodiversity net gain metric.
The Environment Act contains a new minimum 10% biodiversity net gain condition for planning permissions, and is expected to become mandatory in November 2023. In anticipation a ‘Biodiversity Metric’ calculator has been designed by Natural England. The metric is a spreadsheet that uses habitat features to calculate a biodiversity value of a site as ‘biodiversity units’. The value is calculated using the size of the habitat, its quality and location. The metric assesses existing habitat and proposed new habitats created by a development or land change. The calculator is available to use now, but it is not yet mandatory to use.
Click here for a link to the Gov.uk guidance and access to the Biodiversity Metric calculator. There is a separate Small Sites Metric, which is a simplified version of the main Biodiversity Metric, and applies to sites that meet certain criteria. The small sites metric is expected to become mandatory from April 2024:
An 8-week public consultation on the biodiversity metric ended on 27 September 2022 and the Government has published a response outlining some key changes that have been made to the biodiversity metric and the user guide as a result of the feedback, and other matters that will be taken into account in future major updates.
Click here for a link to the consultation response. Some points of note include:
- New habitat classifications are included within Biodiversity Metric 4.0.
- The calculator includes a spatial risk multiplier that is designed to incentivize off-site habitat interventions to be close to the development site impact where possible.
- The biodiversity metric calculation tool includes a new tab which will require metric users to record all irreplaceable habitats present on-site. The habitat type, extent (area or length), and post-intervention status (retained, enhanced, impacted) will need to be recorded.
- Other metrics that measure other aspects of biodiversity, such as species, can supplement but not replace a completed biodiversity metric calculation tool or small sites metric calculation tool.
- Those completing the metric will not need to have received formal training or accreditation, although it is recommended that metric users are qualified in a suitable way to allow them to meet the competency requirements of using the metric. Competency requirements are set out in the user guides.
Mandatory biodiversity net gain (BNG) as set out in the Environment Act applies in England only. The Town and Country Planning Act 1990 will be amended and is due to become law in November 2023. As a developer (unless the development is exempt) you must try to avoid loss of habitat to a piece of land you plan to develop. If you cannot do this, you must create habitat either on-site or off-site to deliver a minimum 10% net gain (habitat must be secured for at least 30 years via planning obligations or conservation covenants). Where this is not possible, the government confirmed in February 2023 that statutory credits would be made available as a last resort (evidence must be provided for this option). The government will invest in habitat creation elsewhere in England, and land managers in England could get paid by selling biodiversity units. Developers will be required to submit a Biodiversity Gain Plan with their planning application, including the biodiversity metric 4.0, to demonstrate at least 10% BNG. There will be an online service to record biodiversity net gain from November 2023.
Click here for the latest Gov.uk guidance on understanding biodiversity net gain and how to sell biodiversity units.
For developers, agreeing how the BNG will be achieved early on in the development design process will be critical to ensure the success of securing planning permission. Understanding the ecological value of your site will be vital in determining how your land can be developed, with some habitats being more valuable, and thus more expensive, to replace.
