47 Lorenzo Tripodi TOWARDS A VERTICAL URBANISM SPACE OF EXPOSURE AS A NEW PARADIGM FOR PUBLIC SPACE Introduction Object of this paper is to provide a framework to understand the se- mantic value of walls and, more in general, of urban surfaces, as key elements in the contemporary urban economies, and as a contested terrain in the quest for domination of the daily visual landscape of citi- zens. Vertical architectural surfaces reveal nowadays an increasing im- portance as communication devices: they are constitutive parts of the system of distribution and display of symbolic values. We are talking about a process geared to the general shift towards symbolic economy (Harvey 1989; Lash e Urry 1994). No more site of production for material goods, no more privileged ield for residential concentration, inner city becomes mainly the site for representational exchange. The contempo- rary city takes the substance of a node concentrating and regulating lows of diverse nature, which increasingly manifest themselves as im- age production and consumption forms. In my research I argue that we are observing the early symptoms of a vertical urbanism (Tripodi 2008). It is not my intention with this term to refer to phallic apotheosis à la Delirious New York, still describing an extreme extrusion of horizontal surfaces declined to particular architectural solutions as skyscrapers and high rise building. Rather, what is meant here is a trend in urban devel- opment in which the semantic use of vertical surfaces tends to over- come the horizontal logistic use of spaces in engendering value and determining urban transformation. The following paper is aimed at investigate such transformations, adopting the concept of cinematic city to describe an emerging in- carnation of the post-fordist metropolis; one where image production stands out as the complex production/consumption chain reshaping the urban experience of citizens as an essentially visual one; a metropo- lis where the space of exposure becomes the structured embodiment of public space, designed to optimise the exposition of city users to the spectacle of goods, impressed, entertained, directed by lows of com- modiied images. Before entering the discussion of seemingly abstract deinitions, I will provide some examples illustrating the phenomena I am referring to,