The Biodiversity Net Gain (BNG) requirement, published by the Department for Environment, Food and Rural Affairs, has been mandatory since 12 February 2024. Its aim is to create new, or improve existing, natural environments by requiring new developments to have a quantifiably positive impact on biodiversity, compared with what was there before. Developers will have to deliver a BNG of 10% – which means a 10% improvement in the quantity or quality of the natural environment.
For the first time, the BNG regulation provides a measurable target for the improvement of the natural environment, potentially leading to a wider uptake of nature-based solutions.
There is irrefutable evidence of the positive impact nature has on humans. Benefits include improvement in mental and physical health, increased productivity, mitigation of the urban heat island effect and overheating risk, and better indoor and outdoor air quality.
Nature-based solutions are also key to adapting to and mitigating climate change, by improving flood management and water quality, riverbank erosion, biodiversity, and carbon sequestration. However, nature-based solutions are not widespread.
The House Of Lords Science and Technology Select Committee recently published the report Nature-based solutions: rhetoric or reality?, which looked at their contribution to reaching the UK’s net zero target. It noted that ‘while the government’s ambitions for nature-based solutions are admirable, there is a clear and present danger that they will not be achieved, and this could undermine the target of net zero by 2050’.
A key challenge in our industry is quantifying the impact of nature-based solutions on the performance of buildings’
One challenge is the perception that green spaces are more costly and require higher maintenance. The lack of quantifiable evidence of social benefits reduces the ability to undertake cost-benefit analysis, and disincentivises government from regulating and funding them.
A key challenge in our industry is quantifying the positive impact of nature-based solutions on the performance of buildings. It is not, for example, easy to model their effectiveness in reducing the urban heat island effect in cities and overheating risk in buildings. A lack of quantifiable evidence could have contributed to the decision not to include green infrastructure as one of the proposed mitigation solutions in the recently introduced Part O – the assessment and mitigation of overheating risk in new homes in England.
How can we overcome the challenges and support the uptake of nature-based solutions? Embed information on their benefits at all levels of professional training and education, but also inform clients, policy-makers and the public.
Identify existing success stories in other countries where policies and initiatives have made a measurable difference. Research industry and policy to quantify benefits, so professionals can better represent the long-term benefits of nature-based solutions and implement them in proposals.
A great initiative by the Climate Change Committee is looking to commission a series of projects to feed into the Climate Change Risk Assessment 4th report analysis. One of the projects will focus on urban heat, looking at the impacts and costs of adaptation at the national, city and building scales (bit.ly/CJHRI24).
A second project will look at the health impacts from extreme heat (mortality, morbidity and impacts on health services). The invitation to tender is due in mid-March 2024, and more information can be found at bit.ly/CJExHe24
The government will be convinced of the benefits of nature-based solutions if they are quantified – for example, increased productivity, health improvements, NHS savings, jobs creation, increased value of building assets, and savings on flood-recovery costs.
Government buy-in is important to implement nature-based solutions at national level (through planning and other policies) and local authority level (by providing resources to implement and regulate urban greening).
The London Plan sets a good example of a local authority requiring all new developments to include urban greening. London has the resources to regulate the implementation of such policy closely, but not all local councils have the funding and knowledge to do the same.
Increasing public understanding of the benefits of green spaces and biodiversity is key to the uptake of nature-based solutions. Changing the narrative from ‘nature for nature’s sake’ to ‘nature for people’ will be fundamental to changing established perceptions.