Author: Sam Stevens, Head of Advanced Technologies

How do we make large scale biodiversity interventions in urban environments? Could the main purpose of a building be to boost biodiversity in the city? What if developments in the future needed to go beyond 10% Biodiversity Net Gain?

Legislation earlier this year requires all future developments in England to deliver a minimum of 10% Biodiversity Net Gain (BNG) to ensure that ‘habitats for wildlife are left in a measurably better state than they were before’.

According to the UK government, there are currently three viable ways to achieve the required BNG. Either by creating 10% biodiversity on or off-site or by buying biodiversity units on the market.

However, according to Dr Sophus zu Ermgassen at the University of Oxford, there are ‘governance gaps’ within the new policy which relate to a lack of capacity and ecological expertise required to effectively monitor the biodiversity gains delivered on the site of new developments. The current policy also fails to address the ‘Quality vs Quantity’ debate, which argues that it is the quality of a protected area that really matters – allowing for the broadest range of species to adopt that habitat as their own whilst helping to facilitate species' movements and migration patterns.

It might be more impactful if we were to focus our efforts on creating and supporting larger areas of biodiversity within and across our cities. 

We envisage a scenario where a new building typology might emerge with the main purpose to increase the biodiversity net gain of an area and to absorb CO2. We could even utilise underused or forgotten structures to rewild our cities whilst creating large biodiversity hubs and wildlife corridors that intersect neighbourhoods and link up with the rural spaces beyond.

Acting as a new green lung for the city and safe haven for a wide range of species to inhabit, these schemes could make an increase in BNG requirement more viable by offsetting the development of sites where the delivery of a 10%, or more in the future, increase in biodiversity just isn’t possible.

Smaller scale interventions remain essential and generally more easily achieved, providing not only an opportunity to enhance biodiversity, but to also improve local wellbeing. Meanwhile larger and combined biodiversity contributions have the potential to bring wider benefits and to generate an impact on an exponential scale. In the future, they might also allow us to strive towards achieving higher biodiversity net gain targets.