What exactly is Biodiversity Metric 4.0?
Natural England describes Biodiversity Metric 4.0 (BM 4.0) as “a biodiversity accounting tool that can be used for the purposes of calculating net gain”. Under the new Environment Act 2021, the UK government introduced a mandatory biodiversity net gain obligation (which will start to become effective from November 2023) making Biodiversity Net Gain a legal requirement for nearly all new developments in England. Biodiversity Metric 4.0 is THE KEY TOOL that supports the delivery of the biodiversity net gain obligation, and its use will be compulsory. It’s important to understand it!
So what exactly is this tool? Biodiversity Metric 4.0 was designed to provide a standardised approach to assessing the biodiversity impact of development projects, and to ensure that the impact is fully accounted for and compensated for. In other words, no matter where you are in England, the tool ensures biodiversity is measured in the same way. We’ve touched on this in other blogs but to briefly review, Biodiversity Net Gain requires that any new development will be required to submit a Biodiversity Gain Plan that accounts for their on-site biodiversity score pre development and details how they will provide a minimum net gain of 10% to that biodiversity over the next 30+ years.
Natural England, along with the Department for Environment, Food & Rural Affairs (DEFRA), created Biodiversity Metric 4.0 as a habitat based approach to measuring a site’s biodiversity and then appraising the area’s importance and impact to the ecosystem at large. Biodiversity Metric 4.0 uses habitat features to assess the site’s value. This is based on a set of ecological characteristics that are important for biodiversity, such as habitat quality, condition and location. These habitat characteristics are used to assign a score to the site, counted in biodiversity units (BUs), which reflects its overall biodiversity value. The biodiversity units are then used to determine the net gain or loss in biodiversity resulting from a development.