As we know, biodiversity and biodiversity net gain (BNG) are both hot topics at the moment. December’s COP15 ended with a landmark agreement to guide global action on nature through to 2030. While it will be a big challenge, BNG delivered in the right way, offers a genuine opportunity to make a meaningful contribution to nature’s recovery. Here are my top tips on how landscape architects can be ready for what’s big in biodiversity in 2023.
Together is Better
The great thing about BNG is that it combines the skillsets of the landscape architect and the ecologist. Understanding the legal & policy framework for wildlife protection and biodiversity gains is essential for ensuring a client’s legal compliance and facilitating best practice, so getting in touch with an ecologist to check requirements before beginning a project is a must.
Understanding Net Gain
Current legislation states that a site will only be required to achieve a gain for biodiversity in accordance with the National Planning Policy Framework 2021. However, this will change in 2023 when BNG becomes mandatory as part of The Environment Act 2021. By law, sites will have to achieve a minimum of 10 percent net gain. Some local authorities are even planning to aim for a 20 percent net gain, so make sure you understand exactly what your local authority wants to achieve.
The Biodiversity Metric
Another cause of confusion is the current metric used to calculate BNG. In essence, the biodiversity metric works on the trading rule principle; you need to replace or enhance habitats that are the same as, or better, than those habitats being lost. For example, if you are going to lose trees on a site, you cannot replace these with wildflower meadows.
BNG uses the biodiversity metric designed by DEFRA. The current version is 3.1 but this is expected to change in January 2023, so make sure you and the project ecologist are using the correct version.
Habitats and their value
The types of habitat and how habitats are valued can also leave people scratching their heads. Given green space in urban areas is limited, it is extremely valuable. Take street trees as an example, they have a very high biodiversity unit value so we always recommend adding as many street trees into designs as possible. At the other end of the spectrum, vegetated gardens have a small biodiversity unit value, and this should be taken into consideration when you are designing your project.
Also bear in mind that whatever is being created or enhanced has to be managed and monitored for at least 30 years so ensure that you have implemented practical solutions that are climate-change-proof.
Like many things, achieving BNG is a numbers game and by working with an ecologist (or a team of ecologists) you will quickly understand how to best maximise and future-proof your project.
It is very easy to get caught up in getting the 0.02 hectare of scrub planting here to get an extra 0.01 Biodiversity Unit there, but whatever is being recommended, should genuinely support nature’s recovery and strive to meet the COP15 2030 target.
About Biodiverse Consulting
Biodiverse Consulting was founded in 2019 to help companies in the built environment sector achieve sustainable and responsible development. It primarily provides ecology services and specialises in biodiversity net gain (BNG) and nutrient neutrality.
It has a range of clients including Dysart Developments, Taylor Wimpey North Yorkshire, Gleeson Regeneration Ltd, Pegasus, and The Wildlife Trusts. It is actively recruiting more ecologists to join its expanding team.