I've been spending time over the last month getting to grips with Petra Kempf's remarkable publication You are the City.

Subtitled "Observation, organization, and transformation of urban settings", the main element of this publication are 22 sheets of clear acetate, onto which are printed different conceptual layers and frameworks of a city. It's based on a earlier project called Met(r)onymy 1, from 2001.

In 'You are the City', the 22 diagram drawings are split into four operational categories: Cosmological Ground; Leglisative Agencies; Currents, Flows and Forces; Nodes, Loops and Connections.

By combining different sheets, and adding layers, a huge range of different compositions can be created - a handmade decon version of SimCity. It invites the user to make new urban connections and realities, as different spatial arrangements and possibilities reveal themselves. In these digital days it's quite refreshing to play with something so low-tech and tactile. The slick sophistication of digital interfaces often make it easier to gloss over them, here the simple act of shuffling clear plastic sheets and seeing the resultant overlays makes for a contemplative pleasure.

Accompanying these diagrams is a slim pamphlet of accompanying essays, brief user guidelines, and notes on each of the diagram layers (referred to as index cards). Kempf herself calls these diagrams an 'adaptable framing device' with which to decode current and developing urban conditions:

"It provides a tool to observe, organise and outline the dynamic structure of cities in a non-hierarchical manner. Thus the urban construct can be studied and revealed in multiple ways, without assuming a specific order. Although we will never fully comprehend the entire complexity of a city in one moment, we can understand the urban construct through the interaction of its parts. This set is comprised of twenty-two transparent index cards that can be either viewed one at a time or in various overlaid combinations. By isolating and superimposing individual components, new perceptions and viewpoints will emerge. There are as many interpretations of cities as there are people."

It reminds me strongly of a book called Ubiquitous Urbanism, the publication of a studio project a Columbia Graduate School of Architecture, Planning and Preservation led by Zaha Hadid, which follows a similar approach of layering highly abstract functional layers into a rich, dense Suprematist construction.

Layering is preferred to the traditional town-planning conceit of zoning to create a greater intensity of urban experience. These mapping exercises are first applied to a number of American cities to test their fit, before the final application as a theoretical project for Tokyo.

This is what Queen Zaha has to say in her introduction:

"My proposal to the studio was to pursue again what has been the undercurrent of my preoccupations over the years and, I claim, has been until recently the central ambition of twentieth century architecture: the synthesis of architecture and urban planning as a three-dimensional as well as social art and science. ... A new approach to integrating architectural intervention had to be posited in the face of the seeming exhaustion of large-scale planning and against the postmodernist and deconstructivist onslaught ."

In You are the City there is a similar attempt to try and work across the schism between architecture and urbanism, using the diagrams and their levels of abstraction as means to see things in a different way. Catherine Ingham, in one of the accompanying essays, Cities of Substance, Cities of No Substance, puts it thus:

"The diagram is one of of the only mechanisms by which conventional thinking about cities can be located and dislodged. The diagram is where conventions, givens, are wrestled with ... Kempf uses abstraction, aggregation and overlay to subvert the conventional urban plan."

You are the City is a powerful antidote to most city-planning exercises, a conscious attempt to free up rigid spatial thinking and start thinking about networks and connections instead.

Petra Kempf can help us move from the notion of ubiquitous urbanism to that of the continuous city.