At the beginning of August Defra launched a consultation on the biodiversity metric 3.1. In this short blog, Lesley Wilson who leads on IEMA’s biodiversity work, sets out the recommendations that the Institute has made to Defra for getting the most out of the metric.

The metric will be an essential tool that underpins the upcoming mandatory requirements in planning regulations for biodiversity net gain.

The consultation consisted of eight questions including the need for case studies, training, accreditation for metric users, the application of the spatial risk multiplier values and ways to support better measurement of losses and gains, and the design of habitat enhancements.

On Monday 12th September IEMA hosted an energetic workshop to engage IEMA members and other interested professionals to create a response to the consultation.

Based on the discussions that took place, a summary of our recommendations is as follows:

  • Accredited training should be developed for metric users that is supported by the full range of relevant professional bodies
  • There should be a definition of a ‘competent person’ in the small sites metric in regard to ecological understanding
  • More case studies and guidance are needed across a range of examples to create a library of information for metric users to tap into
  • There needs to be included in the metric a link with marine net gain and meanwhile, guidance should be provided on using the metric at the interface of intertidal and marine areas
  • The metric must align with updates happening to tools referenced in, and related to, the metric

The Defra biodiversity metric Version 4 will be published in November 2022. Minor updates to the metric will continue as and when necessary and a major update will take place every 3-5 years.

Mandatory biodiversity net gain will be introduced into planning regulations in November 2023. Read IEMA's response to the consultation here.

Join IEMA’s new Biodiversity and Natural Capital Network – sign up to receive information about consultations and national and international initiatives such as TNFD, informative webinars and guidance, and more.

Sign up to the IEMA Biodiversity and Natural Capital Network event at IEMA’s Connect 22 member conference: IEMA Biodiversity and Natural Capital Network – Sowing the Seeds of Sustainability - IEMA Connect 2022: Global environment & sustainability conference (

Photo of Lesley
Lesley Wilson

Policy and Engagement Lead

Lesley is Policy and Engagement Lead at IEMA with a focus on biodiversity and natural capital. Lesley also supports IEMA’s role as Secretariat to the UK Business and Biodiversity Forum, working with businesses to raise the profile of, mainstream, and share good practice in, biodiversity. Lesley joined IEMA in December 2021 after 11 years delivering projects, programmes and solutions for business in the field of environmental sustainability for the British Standards Institution (BSI), including ground breaking standards in biodiversity net gain and natural capital. Lesley has a qualification in business management (MBA) and climate change management, and mentors environmental students at the University of Westminster.


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