Rob Harrison, Harris Lamb’s in-house expert in biodiversity net gain, is set to offer guidance and support to clients looking to enhance their green credentials.

Principal Ecologist Rob is part of the CIEEM’s (Chartered Institute for Ecology and Environmental Management) Biodiversity and Environmental Net Gain Task Group, which was involved in a vital consultation process that will see biodiversity net gain (BNG) become a mandatory element of the English planning system.

In July, the Defra Biodiversity Metric 3.0 was published. The document will become the metric used to calculate and evidence whether a project has achieved the BNG requirements set out in the Environment Bill. 

By definition, BNG is the approach taken to development, and/or land management, which ensures that the natural environment is left in a measurably better state than it was prior to the project being undertaken.


Rob said: “BNG has been an important factor for some years, with developers keen to state that they’ve taken it into account when undertaking projects. But Metric 3.0 changes thing – it actually measures the changes that have taken place, calculating the existing baseline value of a site and its predicted future biodiversity value, including any contributions made through the creation or enhancement of  habitats offsite. 

“In short, saying that steps have been taken will no longer be enough – the actions have to be tangible and lasting.

“Along with my CIEEM colleagues, we have worked to explore BNG approaches and through extensive consultation with stakeholders, we were able to develop a range of good practice guidelines for developers to follow in order to demonstrate the steps they were taking,” he said.

If followed correctly, the guidelines will support developers and consultants in creating lasting, proven gains in habitats that will aid the recovery of ecosystems and the benefits they provide.

Rob added: “There has been extensive awareness around the Environment Bill in recent years and many developers are already factoring net gain into their development projects. We have worked with a wide range of commercial and residential clients to ensure that their policies encourage a net gain approach.

“Having been involved in the consultation process for BNG best practice guidelines, I am very keen to share the research and knowledge gained during the process with clients to benefit future BNG contributions.

“As the busy ecology survey season begins to draw to a close, the team will be looking to work with clients over the coming months to explain how the metric can recognise the negative impacts on habitats arising from a potential development and calculating how much and what kind of new or restored habitat is required to ensure BNG within a project.” 

To book online or face-to-face sessions on the metric and good practice guidelines, contact Rob on rob.harrison@harrislamb.com.