Space Syntax & the future of urban planning software

Notes from a lecture given at the Lincoln Institute of Land Policy
23rd March 2011

View a summary of the presentation on YouTube

Opening comments

Good afternoon. I am delighted to have this opportunity to report on my progress as this year’s Lincoln Loeb Fellow. My brief today is in two parts: first, to describe my work as an architect and urban planner at the strategic consulting company, Space Syntax Limited; second, to say something about where I think my practice, and the field generally, is heading.

In doing so, I want to make special reference to new technologies and new methods of communication that have emerged in recent years.

A plan to transform an established business
“Space Syntax” is an evidence-based approach to planning and design, with a focus on the role of spatial networks in shaping patterns of social and economic transaction. First developed at University College London, it explains, scientifically, why the continuously connected city is a good thing and it exposes the risks that come from sprawl and disconnection. It has much to say about the benefits of density and the hazards of urban fragmentation. It gets us away from simplistic banners like “New Urbanism” or “Landscape Urbanism” by providing a detailed, forensic description of the city.

Space Syntax is best known in the UK but, over the last fifteen years, we have established a network of Space Syntax consulting companies to take the approach into a growing number of countries. Although not immune to the ebbs and flows of the market, we have a commercially successful operation.

Yet, in collaboration with UCL, we now plan to make it available at low or no cost, to as many people as are willing to take it up. More than that, we are about to open up the “source code” of the software to anyone who wants to get their hands on it. We are, in other words, about to publish the recipe for our secret sauce.

In my talk today I will argue that this can only be a good thing.

I want to start with a problem: the “perils of taxonomy”; that is, dangers inherent in the rigid divisions that we take for granted between architect, planner, transport planner, landscape architect, real estate lawyer and urban economist. I could go on to include the risks created by the distinctions we draw between planning and management or, within professions, between community planners, development planners and permit planners. Between academics and practitioners.

The institutional organisation of our professional bodies is carried through into projects such that knowledge itself is also often partitioned. We inherit this taxonomy from 19th century Natural Science and the effort to categorise knowledge.

It seems that when we try to describe the way things are, we put objects – we put ourselves – in boxes. Yet, these boxes seem to work against us, against the emergent continuum that we witness as soon as we walk into the real world.

And they work against the places we create when we leave the architects to do the buildings and the transport planners to do the streets. Witness the scarred urban centres that our divided professions have created. I know the role of planning is to mediate between scales and between activities, but again we divide planning into so many discrete areas of practice that we reinforce separation rather than reduce it.

The irony of this is that each of these disciplines has one important thing in common – an interest in space: how it is laid out, where assets are placed within it, how people move around it, whether it is of value, the degree to which it is safe, how it fosters community interactions  and how it can be bought and sold.

About forty years ago, Bill Hillier began to explore these common connections, using the notion of space as a framework onto which the social, economic and environmental performance of places could be hung.

Published in 1984, Hillier’s first book, “The Social Logic of Space” sets out a theory of space – specifically, a theory of spatial layout: how the layout and connectedness of spaces in buildings and in cities influences the ways in which these places are used by people. Then, how these patterns of use have social, economic and environmental implications.

Written with academic partner Julienne Hanson, it describes the two-way relationship between how different societies organise space to reflect their cultural identities and how, in return, those spaces then organise social relations. From the arrangement of objects in Mongolian Yurts to the labyrinthine walkways of inner city housing estates, Hillier and Hanson’s spatial theory expands on Winston Churchill’s pithy dictum:

“We shape our buildings, thereafter they shape us.”

Hillier and Hanson took Churchill forward in two key ways.

First, by connecting architectural analysis with socio-ethnographic studies, bridging between two worlds of thinking that are typically separated. In architecture, form-function had largely been thought of in machine-age terms: the convenience of living above a garage; the distance from fridge to sink to oven. The Social Logic of Space showed how different cultures assemble space in consistent and different ways: a counter to the International Style of “one style fits all”.

Second, Hillier and Hanson used graph mathematics to describe these socio-spatial differences in rigorous, analytic ways – discovering consistencies of spatial layouts both within and between cultures.

What is Space Syntax?

Space Syntax is used by thousands of scholars worldwide in areas as diverse as archaeology, criminology and cognitive science as well as in its original disciplines of architecture and urban planning.

It has been used by community activists, city municipalities and property developers alike to plan new development from the central business districts of London and New York to the unplanned and informal settlements of Jeddah and Mumbai.

Space Syntax is both a theory of urban planning and a software-based technology.

As a theory, Space Syntax provides a set of principles that describe how space influences human behaviour patterns from movement on foot and in vehicles, to the way people make property location choices, to the social and economic values that are created when people make spatial decisions, whether as individuals or as institutions.

As a technology, Space Syntax software measures certain properties of spatial connections and spatial networks. It simply and quickly describes the importance of space in an evidence-based way. By taking a numerical, scientific approach to space, Space Syntax quantifies aspects of architecture and planning and, in so doing, makes hard-nosed what would otherwise be soft. This brings a potency to the planning and design process, especially when it comes to describing human behaviour, a subject that, in the absence of evidence, becomes all too “touchy feely”.

Although we do not feed actual vehicle movement flows into the model, the remarkable fact is that the spatial accessibility pattern corresponds closely to the actual pattern of pedestrian and vehicle movement in cities throughout the world:

The advent of the personal computer in the late 1980s meant that ever larger spatial networked could be analysed. This led to an understanding of whole-city structures.

Here is the spatial accessibility analysis of London, showing the distinctive radial pattern of highly accessible routes from the centre to the edge:

This pattern is created by the geometry of London’s street network. Our computer model analyses each segment of space between street intersections and calculates how accessible that segment is from all other segments.

Here is the spatial accessibility pattern of Beijing with strong orbital connections:

Here is Tokyo, with strong radial connections and strong orbitals:

Tokyo is famous for its polycentric structure with several major subcentres. Its spatial accessibility pattern makes Tokyo’s economic and cultural identity possible.

The spatial layout of the city is the largest object of human creation – it should therefore be planned as an object in its own right.

As well as making the connection between spatial layout and movement, research has also shown that patterns of spatial accessibility correspond with the historic location of land uses such that land uses in need of more movement, such as popular retail, locate on more accessible streets and land uses that require less movement, such as housing, locate on less accessible streets:

An objective spatial model of the area was produced that accurately reflected the isolated nature of the old Sqaure design with the key pedestrian routes identified at the edges of the Square rather than passing through its landscaped heart:

The image on the left (below) describes the spatial structure of Trafalgar Square before the redesign, showing how isolated the core of the Square was by passing pedestrians workers and tourists. The image on the right shows how the pedestrianisation of the northern side of the Square and the provision of a central staircase would open up the whole of the area up to ‘through movement’, enlivening the public space and shortening pedestrian journeys:

At the scale of a 10 minute walk (800m) settlements can be picked out very clearly. It is possible to see local centres, even high streets.

The most important point though is that these areas are isolated from each other and from the wider city – they could arguably work as well outside city – possibly better, given that they would be removed from the negative effects of air pollution.

The isolation of these settlements started as a process of degeneration – the lack of interaction with global movement meant that it became more difficult to support businesses, which in turn created a lower economic return and less money overall to invest in maintenance – physical quality then became progressively worse.

As physical condition deteriorated, the original set of residents began to move elsewhere but to hold on to their property – from owner inhabitants to landlords.

The settlements then became populated by people, typically new immigrants, with little choice of where to live and often without work or education – relatively expensive and therefore leads to overcrowding

Being excluded from the day to day activity of the wider city, the settlements were, in a way, forgotten. Unfamiliarity leads to the perception that these settlements are unsafe and thus a stigma about the “slums” is born.

This process took one generation.

19th Century approach: improve access but cut against existing grain – lots of disruption to existing residents and loss of fabric:

Using analyses, start to develop route structure to address existing problems:

Double check against transformability, public realm, utilities.


Take example of public/private sector combination. This means that have to start to define urban blocks. Test impact of new routes to develop route hierarchies and to distribute uses and density according to accessibility. Size of developable blocks can vary depending on exact delivery but test block sizes to measure walkability of central areas. Private-led may be bigger, public-led and self organising guidelines.

Result of process is that each settlement has been profiled and used to generate unique, needs based strategy. Physical interventions developed and tested to reintegrate settlements in wider city, and set of guidelines developed that allows financial viability without losing the unique character of each area, and to cause the minimum disruption to existing settlement dwellers.

All of these measures used not just to analyse and profile settlements in relation to strategy but also later as a design tool. Produce thematic maps that could be used as design tools to develop each intervention. Starting point was to look at existing spatial overlap – identify strong areas, spines, fragmented areas. Sketch potential connections between areas and routes to widen. Test sketch against indices to make sure not affecting anything worth keeping

Finally remodel and process to see improvement in spatial structure:

New media
I now want to turn to the future of practice. In order to do so it is important to acknowledge the recent influence of “new media” such as Twitter, Wikipedia and Google. Likewise, the availability of new means of communication, especially “smartphones” such as the iPhone.


Together, new media and new means of communication make knowledge available like never before. And they are bringing knowledge to parts of cities, especially the newly urbanising edges of cities, that have historically been segregated from knowledge.

Commentators are calling this a revolution of equal significance to the invention of the moveable type printing press.

Wikipedia is of special interest, being the largest reference work on the internet. 18 million articles, 365 million readers a year. Its levels of accuracy may come in for criticism but a study in Nature found these to be close to Encyclopaedia Britannica with a similar level of “serious errors”.

What is particularly significant about Wikipedia is that it has been created by the collective, coordinated efforts of tens of thousands of people.


This brings new light to Robert Kennedy’s famous remarks about the power of collective effort:

In my blog I call this “The power of the network” and I’m particularly interested in the human dimension of the digital revolution. How will new ways of learning and communicating influence the places that planners and designers will need to provide in the future?

After all, people are going to new places for knowledge – places that are online and not on land. This isn’t just a challenge for planners and designers but for all figures in authority: politicians, lawyers, physicians. Why go and speak to your politician when you can quickly find out about the issues online and for free?

A challenge for the establishment. Not least the planning process since eg Facebook campaigns can be v powerful.


Equally, a concern that the power of the internet will create a new civilisation of laptop potatoes.

Taking the bedroom romance of When Harry Met Sally one step further – in the wrong direction.

But of course the majority of the film was played out in the city. Technology, whether the telephone or the internet is, I believe, a force for urban good.

And I’m not the only one to see the enormous beneficial potential of new media.


For example, in “The Street as Platform”, a blogpost written by Dan Hill, the argument is made that new technology is enhancing the urban experience – a new civic awareness. An awareness more about outcomes than institutions. About emergence than about planning.

Late last year, Facebook launched “Facebook Places” in an attempt to harness the potential for people to find eachother not only online but also onland.

How digital networks such as Facebook interact with the urban street network is, in my opinion, one of the more pressing practical and theoretical problems of our age.


This is a subject being dealt with here in Cambridge by scholars including Helpman and Benkler.

The simultaneous digital and physical connectedness of urban places is equally of interest to social economists such as Florida and Glaeser.

Another network to consider is the network of over 3,000 academic researchers using Space Syntax theory and technology in universities around the world.

The key issue here is the independence that the researchers enjoy – independence to take the research in new directions. This sort of thing can’t be controlled in traditional, centrist terms.

In a similar fashion, Colin Ellard’s recent popular book on movement and wayfinding includes a generous set of references to Space Syntax – creating, in a small way, the kind of auto-dissemination effect that occurs within mature knowledge networks. In other words, it suggests that Space Syntax is truly global.

The future of practice

Open source
Which brings me to my final remarks about the development of technology and the dissemination of ideas – with reference, in particular, to my own practice: Space Syntax. An additional dimension of the digital story concerns the way in which the power of the digital network can be harnessed to develop software – the software that my company uses to analyse spatial networks.

Now traditionally, software is expensive to develop – you hire a highly qualified programmer, or “hacker” to write it for you; or a whole team of them. They don’t come cheap when working for you is their day job. But the benefit of doing this is that you control your software and dictate its development. Expensive, slow but you’re in control.


An alternative approach to hiring your own hacker is to “open source” the technology development. This means that you open up your software to the world and you let people take a look in and develop it for you. You might still reward them with cash, or you might not if that’s not their thing. Hackers are also motivated by competition to be the better than their peers and to see their work used in practice. Eric Raymond explains how this works in sometimes counter-intuitive ways:

The Open Source method of working requires a leap of faith but its great advantages are that it can achieve better results far more quickly, and at lower cost than the traditional way.


3 thoughts on “Space Syntax & the future of urban planning software”

    1. Hi, Renato

      Thanks for your comment and I’m sorry it’s taken we so long to reply. I have been moving back from the USA to the UK.

      To answer your question, we are looking at all of our software. We expect to make an announcement on September/October.

      Best wishes


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