Our latest paper is out, open access and free to download, in Urban Planning (Cogitatio Press), as part of The Urban Canvas: Spatial Computing in Planning, Analysing, and Representing the Cityscape, an issue edited with Valerio Signorelli, and in memory of Heejung Kwon.
Three Stages, and the One in the Middle
The argument is built around a three-stage model of urban digital transition. The first stage is the Smart City, where sensor networks and real-time analytics form the digital nervous system of the city. We have twenty years of literature on that one. The third is what the paper calls digital habitation, a condition in which physical geography stops being the primary frame of reference, and work, socialising, commerce and leisure move into immersive digital environments.
The closest to becoming real but perhaps the least understood, is the middle stage. The Phygital City is where physical and digital layers are experienced simultaneously and inseparably, in the actual lived environment. Not a dashboard in a control room, and not a headset in a spare bedroom, but the overlay you walk through. It is arguably the condition we, and the cities around the world are rapidly transitioning into.
Why Naming It Matters
Code/space (Dodge and Kitchin, 2005), hybrid space (de Souza e Silva, 2006) and platform capitalism (Srnicek, 2017) all capture early parts of this, and the paper builds on the space of code into the present and speculates on the near future. The claim is that the Phygital City is a qualitatively distinct planning condition rather than a gradual extension of the smart city.
This is not a semantic point. Planners cannot, arguably, govern a condition they have no vocabulary for, and the governance instruments built for the smart city, procurement frameworks, data standards, sensor policy, do not reach the experiential, spatial and ethical questions that an overlay raises. Who has the right to place content in a street they do not own. Whose interface sits between a resident and their own neighbourhood. What happens to the public realm when the view is monetisable. The paper discusses such matters.
Interface, Home, Urban Form
The concept is developed across three registers. Interface design, where the layer is authored and controlled. Domestic space, where the home has quietly become the most instrumented environment most of us occupy. And urban form itself, where the question is what physical cities are for once a growing share of activity no longer needs them.
Grounding it are emerging empirical cases, urban digital twins and spatial computing platforms, including our own work on the digital twin of Queen Elizabeth Olympic Park and Here East, which has been running long enough now to be evidence rather than a demo.
A Horizon, Not an Inevitability
The three-stage transition is treated as a planning horizon that requires anticipatory governance, not as a technological inevitability. Stage three may never fully arrive, and there are good reasons to hope parts of it do not. That is precisely why the Phygital City is the useful place to look, it is the most tractable site for policy and design intervention right now, while the layer is still being built and the decisions are still open.
The Computable City
There is a lineage to all of this, Mike Batty wrote "The Computable City" in 1997, arguing that computers were no longer just tools we used to model cities but were becoming embedded in the city itself, and returned to it in his book length in The Computable City (MIT Press, 2024), tracing seventy-five years of the two converging. Mike was my PhD supervisor, and that argument has sat underneath most of what I have done since.
The book takes the story to the point where the city has become a constellation of computers. This paper is an attempt to pick up the thread from there and ask the next question. If computation is now embedded in the fabric, what happens when it stops being infrastructure and starts being surface, when the computable city becomes visible, addressable and monetisable at eye level in the street. Batty's concern is largely with the city as a computational system. The Phygital City is what that system looks like once it is rendered back to the people living in it, which is where planning has to make its decisions and where, at the moment, it does not seem to know whats coming....
Read It
- Spatial Computing and the Phygital City: Towards Digital Habitation - article page
- Free PDF download
- DOI: 10.17645/up.12412
Published 26 August 2026, open access under CC-BY, so it can be shared, reused and taught from without asking anyone.
Hudson-Smith, A. (2026) Spatial Computing and the Phygital City: Towards Digital Habitation. Urban Planning, 11. doi: 10.17645/up.12412