What is a Biodiversity Net Gain survey and what data does it need?

Biodiversity Net Gain is now mandatory for most new development in England under the Environment Act 2021. A BNG baseline requires accurate habitat mapping — identifying, classifying and measuring all habitat types on and around the site before development begins. This typically requires a topographic survey to establish accurate site areas and boundaries, along with UAV photography or LiDAR data to support habitat condition assessment. The Biodiversity Metric requires precise habitat areas, which means the survey data underpinning the baseline needs to be accurate and reproducible. We produce georeferenced topographic data and UAV outputs that ecological consultants can use directly in their BNG calculations.