News & Insights

The Latest on Biodiversity Net Gain


The turn of the month saw the Government’s landmark Environment Bill pass its second reading by MPs unopposed, indicating an apparent political appetite for this new legislation. This follows the 25 Year Environment Plan, published in 2018, in which the Government made a commitment to “support development and the environment, by embedding the principle that new development should result in net environmental gain.

While wide-ranging, with implications for air quality, water resources and waste management, the provisions of the Bill of particular interest to our clients are in respect of biodiversity net gain in planning and development. Schedule 15 of the Bill establishes that all planning permission will be subject to a pre-commencement condition requiring the developer to submit a ‘Biodiversity Gain Plan’ for the local authority’s approval. The Plan will need to demonstrate that the biodiversity value attributable to the completed development exceeds that of the site pre-development, by a factor of at least 10%.

Shortly before the publication of the draft Bill, Natural England had this summer released the second iteration of the Defra Biodiversity Metric, to provide a quantitative and standardised basis for calculating the biodiversity value of a site. By assessing a number of characteristics, including habitat type, area, condition and connectivity, our Ecologists can use the metric to forecast net changes in biodiversity value. The metric was released for Beta testing phase, with full publication expected in summer 2020. Natural England have indicated the metric would remain unchanged for at least five years to provide a greater level of certainty and a level playing field for practitioners.

Under the draft legislation the Secretary of State would have extensive powers to make further regulations and exceptions in respect of the mandated gains, however in their response to public consultation earlier this year the Government have said they will not “introduce broad exemptions from delivering biodiversity net gain, beyond those … proposed for permitted development and householder applications such as extensions, and will instead introduce narrow exemptions for the most constrained types of development.

However, there remain aspects of the Bill which face significant criticism. The Government’s own impact assessment has estimated the cost to developers of mandating biodiversity gain as £19.9 million per year. Conversely, some have criticised that the ‘Biodiversity Gains Sites’, where land is to be managed to promote biodiversity and thereby offset the effect of developments which haven’t delivered an on-site net gain, are only secured for a period of 30 years.

Having passed the second reading, the Bill would normally progress to the Committee stage for further scrutiny, and onto further stages of the Parliamentary process before becoming law. However, with an election now imminent it will be for the next government to resurrect this bill and/or take the principal forward into new legislation.