Many of our clients ask us about the requirement for 10% Biodiversity Net Gain, where did this requirement come from, does this standard currently apply, and more importantly does it apply to their development sites?

The requirement for 10% Biodiversity Net Gain has gained momentum under the new Environment Act, which is expected to receive Royal Assent later this year. The Act outlines that new developments should achieve a minimum of 10% biodiversity net gain. It is expected that the Act will have a transition period, likely to be 2 years, after which the requirement for 10% net gain is to be applied to all new developments.

So how is Biodiversity Net Gain calculated? Natural England has prepared a metric that calculates what is currently on the site, the habitats and species that are currently there, and then this is compared to what the change will be. Under the Environment Act, if the calculation shows less than 10% then additional enhancements will be required.

Natural England has recently announced their new Biodiversity Metric (3.0) along with a simplified version for use on small (up to 9 residential units) development sites. Natural England has advised that for projects that are currently using the previous version that they should continue to do so unless the client or the local planning authority advises otherwise. This is because the different metrics can provide different figures.

wildflower biodiversity

So why are some developments needing to provide 10% net gain now? Some local authorities have applied the requirement for 10% net gain now either within their newly adopted local plans or as part of their existing adopted core strategy documents. Unfortunately, this is not uniform across the country, with some local authorities ahead of others. This can be frustrating for our clients as it is difficult to ascertain exactly what the local authority will require. We have found the easiest way to determine this is through the pre-application process, where our clients have the opportunity to ask the local authority what their biodiversity net gain target is. We would recommend this approach as that enables biodiversity enhancements to be considered at the onset of the project rather than trying to retrofit enhancements around a ‘fixed’ layout.

If you would like any further information about Biodiversity Net Gain or help to achieve net gain on one of your projects please do not hesitate to contact us on 01666 825646 or