In discussion with James Podesta, Head of Development

With climate change, environmental challenges, and biodiversity at the forefront of discussions in parliament, Monday 12th February marks the enactment of the new law, making biodiversity net gain (BNG) on development proposals[1] mandatory as part of Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021). This will affect developers, land managers and local authorities and is aimed at protecting and enhancing our natural environment.

Developers of sites (of more than nine dwellings and / or larger than 0.5 hectares) are required to return a minimum of 10% biodiversity net gain value either on (the preference) or off (where it cannot be achieved on) the proposed site. This is calculated by the difference in pre-development and post-development baseline assessment and ‘as developed’. The land must then be managed by the landowner for 30 years, remaining consistently biodiverse and showing demonstrable improvements.

It has never been more important for developers to understand the constraints on sites and understand factors such as flood risks, water management, arboriculture, ecology and access, as this could all effect a sites BNG score.  With local authorities obliged to prepare their own Biodiversity Action Plan (BAP), developers can request this to understand the macro-picture in more depth and be fully prepared before any work starts, helping avoid any unnecessary delays and avoid unforeseen costs. Sites can be complex, and understanding the biodiversity baseline at the beginning is vital to understanding whether BNG can be accommodated on or off site, or whether BNG credits need to be purchased.

BNG’s aim is to protect and enhance the environment, wildlife and natural habitats, and the variety of ecosystems which exist and may be at risk during development.  Developers can purchase ‘BNG units’ to offset the biodiversity implications of developing a site. If they’re unable to fulfill the 10% net gain requirement on site, biodiversity units can be bought. It’s important to consider proper delivery of BNG on site as biodiversity offsetting can impact on the already existing habitats or introduce a new species which may affect an already established eco-system.  As we’re still in the early stages of seeing how this law will impact developments and local authorities, only time will tell what influence the law change has on our environment, however with the correct management, we should see positive results. In my view, there are positives to the introduction of regulations which will drive a tangible improvement in biodiversity, a note of caution though around nature and biodiversity not fitting neatly into local authority administrative boundaries and some areas having far more potential than others to accommodate these requirements. Local Authority BAPs will be key to effective improvements, as I believe was envisaged by the authors of the act.

The opportunity for developers to introduce creative ideas from the start of a project to obtain a 10% BNG improvement is an important consideration.  For example, the introduction of blue-green roof infrastructure into a design not only can reduce flooding but by incorporating plants and greenery without the need for additional space, can be a truly innovative way to hit the minimum 10% requirement.

Going above and beyond the quota can also raise the profile for companies who are putting themselves at the forefront of sustainable design.  10% is the minimum, but nothing is stopping a developer from striving to achieve a higher score than required and receiving the recognition for this.

STRI Group projects have considered BNG for years and implement measures from the start to quantify biodiversity in development.  Speaking with an expert masterplanner and incorporating consultants into your project can futureproof any development and make sure BNG is effective long term.  If you need advice or would like to speak to us to find out how we can assist with your project, email and we’d be happy to help.

[1] With limited exceptions