Tim Stonor

Category: Urban form

  • The urban cortex

    The urban cortex

    A talk given at Lombardini22 architects in Milan on 13th May 2025.

    The idea I’d like to explore this evening is that cities serve a higher purpose than we typically credit them with, and this idea is that cities are natural extensions of the human brain. Far from being artificial, alien objects, cities work with us, their users, to help us solve the problems of our times. Cities are extensions of our brains and, just like our brains, cities are sophisticated computers.

    At least they are, if we design them well. 

    Great cities are not just beautiful to look at and stimulating to be in. They are also highly efficient human transactions machines: bringing people together to form relationships and generate outcomes. Cities are the outermost layer of our common existence. Hence the title of this talk: the ‘urban cortex’.  

    One challenge when discussing cities is that urban commentators often begin by describing cities as chaotic, that their street networks are ‘labyrinthine’. This is a lazy approach to urbanism – and not one that we share at Space Syntax. Instead, we’ve spent the last 50 years studying the apparent chaos of cities and discovering regularities within them – of spatial layout, of land use distribution, of density, mobility and the distribution of inequalities. 

    These discoveries help us both to understand cities and to better design them. 

    Cities are not chaotic. We don’t build them by chance. Within their apparently labyrinthine randomness there are structures that organise the ways we move through cities – and interact with each other within them.

    There are regularities that allow us to understand cities – not just as urban scientists might pick them apart but as every day users make sense of the places they’re in:

    • how they feel comfortable in them
    • feel like they want to visit and explore them
    • meet people in them
    • go to work in them
    • invest their time and their money 
    • have fun
    • feel excitement. 

    This is the ‘urban buzz’ that draws people to cities.  

    (more…)
  • 15-minute cities or 15-minute ‘bubbles’?

    15-minute cities or 15-minute ‘bubbles’?

    The motion at today’s Cityscape conference in Riyadh was: The 15-Minute City model will improve quality of life for all communities and can be easily scaled globally. 

    Who would choose to argue against the principles of the 15-Minute City? Walkable. Sociable. Low carbon. 

    Who wouldn’t want any of that?

    But, if not the principles of the 15-Minute City, what we should be deeply concerned about is the experience of translating those principles into practice. 

    My colleague Katya and I are going to argue against the motion from our experience of what many developers and designers are naively promoting in the name of the 15-Minute City. 

    Because what we are seeing in cities all over the world are individualistic, inward-looking, over-localised, gated developments calling themselves 15-Minute Cities. 

    Why do their proponents claim that these are 15-Minute Cities? Well, because they are relatively small, they have a mix of land uses and there’s a varying degree of infrastructure for walking and cycling. 

    But there’s typically very little, if any, public transport and the connections to other so-called 15-Minute Cities usually require the pedestrian or cyclist to cross the major roads and even highways that separate them. So these would-be walkers and cyclists usually end up jumping in a car and driving. 

    We know a lot about this in the UK because the 15-Minute City concept was at the heart of disastrous 20th Century New Town planning, even if we didn’t call them 15-Minute Cities back then.

    Communities – especially women – found themselves unable to walk easily between neighbourhoods because they felt unsafe next to fast cars or having to move through the tunnels that had been built under the highways or up, over and down the bridges that are the visible symbols of civic failure. 

    (more…)
  • Form ⇝ Flow ⇝ Function

    Form ⇝ Flow ⇝ Function

    Many places work in ways not originally intended. The artist’s impression is often unrealised, with public spaces less well used than in the drawings, shops not getting the footfall shown in the CGIs, tracks worn into green spaces painted as pristine in the renderings.

    The actual function of places – as opposed to their intended function – follows the flows set up by the spatial form of those places, independent of their designers’ wishes otherwise.

    It’s risky to think that form follows function if you don’t first understand how the actual functioning of places is a consequence of the flows shaped by their physical forms.

    If you don’t understand how physical forms shape human flows and these flows then support functions (such as sitting, shopping, resting, feeling comfortable or feeling unsafe) then you risk designing the wrong physical forms and ending up with problematic functions.

    So, in the classroom it might be:

    “Form follows function”

    But in reality it’s the other way round:

    Function follows flow, and flow follows form.

    In other words:

    Function follows flow follows form.

    With software that forecasts flows by analysing physical forms, and with design principles shaped by decades of experience, my colleagues at Space Syntax and I have been able to de-risk the design process. We’ve analysed forms, predicted flows and been able to anticipate the functioning of schemes at the earliest stages of design, feeding back our recommended changes to the physical shape of design proposals in order to optimise flows and close the gap between intended and actual functions.

  • Intense relationships: measuring urban intensity

    Enriching design practice by the mapping of human behaviour patterns could transform urban space

    An article published in the Architectural Review on 30th April 2018.

    There’s much debate about how to measure density – dwellings per hectare, bedrooms per hectare or people per hectare; including or excluding major highways, parks and open spaces; the permanent population only or the transient one too? 

    While this gives urban planners something to disagree about, it risks missing the point: great urban places are not created by density; they’re created by intensity. The difference matters. When people describe the buzz of a market they don’t say, ‘Wow – it was so dense’. They’re much more likely to say how intense it was. Density is a word used by planners. Intensity is a word that real people use, and perhaps because it describes the outcomes that people experience rather than the inputs that have gone into creating them. It’s the outcomes that are ultimately more important.

    But planning professionals like density. Even though density doesn’t capture the essence of what it feels like to be somewhere, the term appeals to professional instincts. It describes the raw ingredients that planners have to handle and, once you choose which version of the formula to use, density is easy to measure. It involves a simple calculation of straightforward urban quantities such as the number of people, of houses or of bedrooms, all divided by the geographic area over which those ingredients occur. Easy.

    By contrast, intensity seems more difficult to pin down, not least because it appears to have a subjectively emotional dimension; it speaks of feelings, responses, stimuli; raising problems about how it can be measured. But intensity is also a response to context, to place and above all to people – and here we find clues to its measurement.

    (more…)