Biodiversity Metric

The statutory (official) biodiversity metric is a way of measuring biodiversity value for the purposes of biodiversity net gain (BNG). It measures all types of habitat, including: grasslands hedgerows, woodlands and watercourses. For BNG, biodiversity is measured in standardised biodiversity units. The biodiversity metric measures the biodiversity value of habitats by calculating the number of biodiversity units. It calculates how many units a habitat contains before development takes place, how many units are needed to replace the units of habitat lost and to achieve 10% BNG, through the creation or enhancement of habitat. The formula takes different factors into account, including the habitat’s size, quality, location and type. For created or enhanced habitats, the formula also takes account of (1) difficulty of creation or enhancement, (2) the time it takes a habitat to reach its target condition and (3) distance from the habitat loss.