Biodiversity Net Gain (BNG)
BNG is defined as ‘Development that leaves biodiversity in a better state than before’. A development has to gain a minimum of 10% BNG from the existing site once the Environment bill is passed. The data is usually gained from a Preliminary Ecological Appraisal (PEA) of the site.
The purpose of this assessment is to inform a developer of any key ecological habitats on their project site and surrounding area. This can be used to influence planning designs and to notify the developer, allowing the developer to more accurately estimate project costs and layout.
It is recommended that this process is done early in the planning process and prior to commencing any works. Early planning helps offset potential expensive and/or delays. It is likely that ecologists will work with architects and planning consultants very closely before an application is submitted to ensure BNG is achieved and planning from an ecological perspective is granted.
The process uses the DEFRAS Biodiversity Metric Tool to calculate the baseline biodiversity value of the habitats on-site pre-construction and the biodiversity value of the habitats retained or proposed post-construction. This tool only takes into account Habitats, it does not include mitigation such as bird and bat boxes etc.
Timings
BNG calculations can be performed throughout the year and is optimally carried out before a planning application is submitted following the necessary PEA survey to gather the baseline data.