Performance-based planning
The future of planning / Part 7
The planning system is, ultimately, a health system. Where the National Health Service is tasked with curing us, the planning system’s remit is preventative health: how to stop us becoming sick, lonely or depressed in the first place.
That might seem like a rather abstract connection, but it isn’t. Take almost any issue in planning, and it links more or less directly to a health issue.
Access to public transport or safe cycle lanes determines our transport choices. That also links to exercise, and to air pollution. Investment in water and sanitation infrastructure is about avoiding disease. Energy generation, and the performance of homes is about staying warm in winter, and cool in summer. Trees clean the air, and mitigate heat-island effects. Community infrastructure helps combat loneliness. Lack of adequate daylight is linked to depression and poor sleep. The availability of take-away food maps to obesity, and gambling to anxiety and depression. The inability of families to live near grandparents has a huge cost in care. Biodiversity is about the protection of nature’s life-support systems, upon which our food supply depends, as well as also being key to our own mental health. When COVID19 hit, poor housing conditions and overcrowding led to increased transmission and risk of death, especially for BAME families and communities. Even carbon emissions are, ultimately, a health issue: it’s about the survivability of Earth’s climate. The list could go on for hours.
This inextricable link between places, infrastructure and health was one of the original reasons why the planning system was created, beginning with the Public Health Act of 1848 — the goal of which was to stop the spread of diseases like Cholera.
But in the day-to-day experience of using the planning system today, you don’t hear the word ‘health’ used very often. That’s not because it isn’t there, but because in the 20th century the planning system used a series of categories, tests and typologies as proxies for those things. This is why, for example, hot food takeaways and betting shops have their own ‘Sui Generis’ (‘of its own kind’) land use classes. So do nightclubs, because of the noise pollution. Leather tanning used to have its own industrial use class. The reason: the process involves the use of ammonia, and the air pollution downwind used to be so bad that it needed to be tightly controlled.
Planning in the dark
These proxies are a clever way to deal with things that we know, but can’t measure. But they aren’t perfect. For one, sometimes they can be rather rigid and inflexible, prohibiting certain kinds of hybrid uses or limiting forms of development that would in fact be beneficial to the environment, society and the economy.
But it also means that planning has a rather indirect relationship with the impact of its decisions. We are still very much operating on guesswork, or on case-by-case assessments.
Really this is about the way that knowledge works in the system.
Today, as a society, we have more knowledge than ever about the ways that planning and design decisions affect our health — and a whole range of other economic, environmental and social outcomes too. We know, for example, that living near greenspace and open water increases happiness and life expectancy. We know that access to good daylight has a whole range of health benefits. We know providing protected bike lanes increases cycling, and that in turn increases local retail sales by up to 30%. Again, this list could go on forever.
In fact, our problem today is not that we don’t have enough knowledge, but rather that we have too much. As Atul Gawande argues superbly in his book ‘The Checklist Manifesto’, there is more knowledge in the world today than any practitioner can meaningfully hope to be able to deploy on a given day.
Because while that knowledge may be out there somewhere, much of it is either buried in long research papers that take hours to find and read (assuming they aren’t locked behind a paywall), or it is in the heads of expert consultants. In our current system, every evidence-base and environmental impact assessment has to be prepared on a case-by-case basis. We pay experts to carry out sun and daylight stud, or a wind study, or an assessment of noise impacts on each and every application. And usually we only do it once, on one version of a design.
We simply don’t have the bandwidth to bring to bear all the things that are known somewhere about the potential impact of our planning decisions, or to link them to our own stated policy objectives as we plan.
For example, a typical new home in the UK today emits 30–50T of carbon in its production (in total embodied carbon of buildings represents around 6% of UK emissions). Most of this comes from bricks and concrete. And yet planners will still very often encourage the use of bricks in projects, because bricks are beautiful, and many planners are simply not aware how much carbon is emitted in their production.
The same picture applies to many other outcomes too. At the moment we just don’t have a very good picture of the impact of design decisions. Where we do, it is often patchy and rather distorted, in that certain topics will receive a lot of focus, while others won’t. To a large extent, we’re still planning in the dark.
From form to performance
As these big social, economic and environmental challenges loom ever larger over our lives, and as the costs of poor health, care, extreme weather events, pandemics and poor mental health rise higher and higher, we are beginning to see a shift in focus. The planning system will once again be seen more and more as a preventative tool. When it comes to buildings and neighbourhoods, our focus will be not just on form, but on performance.
And here, once again, technology will have an important role to play.
Performance-based rules
One of the shifts we’re beginning to see is a move towards planning rules that focus on performance outcomes. So for example, regulating noise, traffic, pollution, carbon emissions or land drainage. The UK’s current consent-based system actually often does a good job of this already by adding conditions to planning permissions, but it does that on a case-by-case basis. Increasingly we’ll see rules that rely less on proxies, and instead regulate for the outcomes directly. For example, setting noise limits in dB, or air pollution in ppm.
By regulating the outcome, rather than the presumed solution, we open-up room for creativity and innovation. So for example, rather than switching from ‘you must use bricks’ to ‘you must not use bricks’, instead we can just set a requirement that any development must be net zero embodied carbon, and leave it up to the market to innovate (for example, by developing low-emission bricks). We can give people and enterprises more freedom, whilst protecting and augmenting the stuff that matters.
I think a good example of this is the Biodiversity Net Gain (BNG) rules introduced in England earlier this year, which provide a framework for ensuring that, in terms of natural habitats, new development leaves places better, not worse, than we found them. The only problem with them is that, in our current system, this means more bureaucracy and cost. The challenge (which some have begun to explore already) is how to create digital tools that make calculating and complying with these rules simpler and faster.
Performance data and models
The other superpower we have in this effort is data. Ever since that first map by John Snow of the Broad Street pump during the Cholera outbreak of 1854, the potential of data to inform urban planning has been clear. Today the range and quality of data we have is astronomically greater. Sensors and citizen science projects across cities can give a real time record of air quality, traffic, noise, water levels, or economic activity.
We also increasingly have ‘parametric’ data-models that allow us to simulate the likely impact that certain development patterns will have on people and the places around them. Not just physical characteristics like sun, wind and noise, but also behavioural, health and economic impacts.
Imagine tools where, as you plan, you can see a 3D map of the place, overlaid with hundreds of layers of data about almost everything you can think of. As you design, testing out different development patterns, you can instantly see estimations of the likely impact of your decisions. Feedback and analysis that once would’ve taken weeks and £000s could instead be done in seconds.
This may sound a bit sci-fi, and unlikely, but much of the data, and many of these technologies and models are already here somewhere. There are companies building prototypes, products and services around spatial data analytics (for example Urban Intelligence, Space Syntax, Urban Three), mapping data to issues like social and racial inequality (for example, Centric Lab) and parametric modelling tools (Grasshopper, Hypar, Block Type, and our own project, BuildX).
The issue is that today all these efforts are rather fragmented and bound within existing business models and ways of working.
New knowledge institutions and markets
My suggestion for governments and professional institutions would actually be to not begin with the technology itself at all, but instead to ask: what new institutions, shared libraries, data infrastructure and standards are needed to bring all these things together? What new markets for data and knowledge do we need to incentivise people to produce and share data, and experts to turn their models into ‘linked-data’ that people can trust, use and add-to.
The Singapore civic digital twin is a signal of what that future might look like. Dan Hill and his team at Melbourne School of Design are exploring how that idea could be taken further towards that holy grail of mapping development proposals to health outcomes within the twin itself.
The purpose of such platforms and tools is not to create a single source of truth, or a planning system where we no longer argue and debate, but rather a civic knowledge platform – a continuously-learning body of common-knowledge that allows those debates to be ever better-informed. To understand the trade-offs, and to avoid storing-up costs for the future. It’s a chance, perhaps, to bring planning back to where it began — as a strategic tool to allow more and more people to live longer, happier and healthier lives.
This is Part 7of a series. The first part is here.
