Biodiversity Net Gain Assessment (BNG)

In England BNG is becoming mandatory under Schedule 7A of the Town & Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021). 


This means all development will be required to deliver a biodiversity net gain of at least 10%, resulting in more or better quality natural habitat than prior to development, ensuring a measurably positive impact on biodiversity. 

Our BNG experts have experience in delivering comprehensive assessments and reports for developers looking to acheive BNG using the Department for Environment, Food & Rural Affairs (DEFRA) Statutory Biodiversity Metric and Small Sites Biodiversity Metric. 


All habitats within a site are assesed in the metric for:


- Distinctiveness (e.g. species diversity, rarity, richness)

- Condition (e.g. quality; good, moderate, poor)

- Connectivity (e.g. proximity to other similar habitats)

- Strategic Significance (e.g. identified at a local level to be ecologically desirable)

To achieve BNG a development must show evidence that it will increase the biodiversity value of the site by at least 10%.


If this is not achieved mitigation plans must be put into place by enhancing the on-site biodiversity wherever possible or creating new habitats elsewhere, known as biodiversity off-setting. 

John Wenman Ecological Consultancy 

1 Diesel House, Honey Hill


Berkshire RG40 3BL

0118 327 1810