10% biodiversity net gain: it’s coming …

Sustainable development sits high on the political agenda which makes improving biodiversity a key driver for developers, land owners and local planning authorities alike. Biodiversity Net Gain (BNG) is an approach used to improve a sites biodiversity value. Once applied, on completion, a site will have a positive ecological impact, delivering improvements through habitat creation or enhancement after avoiding or mitigating harm.

What is Net Gain?

Biodiversity Net Gain (BNG) sits within the Environment Act. The Act requires all development schemes in England to deliver a mandatory 10% biodiversity net gain to be maintained for a period of at least 30 years. The concept seeks measurable improvements for biodiversity by creating or enhancing habitats in association with development. Development proposals must “leave biodiversity in a better state than before”.

However, the requirement to demonstrate 10% biodiversity net gain with planning applications as a consequence of the Environment Act 2021 has not yet been engrossed in law. This is despite the launch of the new Biodiversity Metric 3 by DEFRA, which is designed to provide ecologists, developers, planners and other interested parties with a means of assessing changes in biodiversity value (losses or gains) brought about by development or changes in land management. The metric is a habitat-based approach to determining a proxy biodiversity value.

Evidence of an increase in biodiversity will require a baseline assessment of what is currently present on a site and then an estimation about how proposed designs will add to that level, and latterly support post-construction evidence that a 10% gain has been delivered.

The Environment Act and Commencement of the Requirement

Part 6 of the Environment Act 2021 is entitled ‘Nature and Biodiversity’. Within this part is section 98, entitled ‘Biodiversity gain as condition of planning permission’. It simply says that ‘Schedule 14 makes provision for biodiversity gain to be a condition of planning permission in England’. So it simply redirects the reader to Schedule 14.

Part 1 of Schedule 14 contains the requirement for biodiversity net gain. However, section 147 of the Environment Act 2021 tells us when the Act commences. Section 147(3)(s) tells us that Part 6 of the Environment Act 2021 only comes into force ‘on such day as the Secretary of State may by regulations appoint’. Thus, it is not until further secondary legislation is made by the Secretary of State that Part 6 of the Environment Act (where the 10% requirement exists) come into play.

Implications for Uplift

Whilst IPS appreciates the importance of securing biodiversity gains and ecological benefits, there are concerns regarding the minimum net gain requirement.

Current guidance from all governing bodies including DEFRA, Natural England and The Environment Bill which was introduced on the 15 October 2019 by Environment Secretary, Theresa Villiers, set a threshold of 10% net gain. Some authorities (such as Swindon Borough) have proposed a higher % value. There is significant evidence that even a 10% uplift is problematic. Research conducted by Environment Bank strongly indicates that it is extremely difficult if not impossible to provide a 10% net gain in biodiversity on-site within a residential proposal without an unviable reduction in developable area or a significant proportion of that net gain being proposed off site via offsetting.

This is of considerable concern for the deliverability and viability of sites, particularly within areas with a current housing shortfall. There is a strong preference for onsite mitigation, but as considered above, this is extremely unlikely that this will be practical across many sites, thus impacting on deliverability.

We highly recommend that our clients get to grips with potential biodiversity net gain requirements at an early stage of site identification and design. If you’d like to discuss potential planning requirements and/or implications for Biodiversity Net Gain then please do get in touch.