_FACTSColumbia University is both a leading academic institution of the world and one of the most constrained for space. At 326 square feet per student, Columbia has less square footage per student by far than other leading research universities (compare to Yale at 866 sq. ft., Princeton at 828 sq. ft. and Harvard at 673 sq. ft.). The President of Columbia declared that \”in order to continue expanding our leadership in the most promising areas of teaching and research, especially in the sciences and the arts, we urgently need to build and equip new laboratories, new classrooms, and new studio and performance spaces.\”Early in 2003 Columbia announced its proposal for a new campus in the Manhattanville section of West Harlem, and immediately began consulting with neighbours, community groups, elected officials and local business leaders.The proposed Manhattanville development site consists of approximately 18 acres from West 125th Street to West 133rd Street between Broadway and Twelfth Avenue, plus three blocks immediately east of Broadway from West 131st Street to West 134th Street. _HIPOTHESISThe proposed Master Plan tries to achieve, as declared by its designers, an open and welcoming environment that integrates the University with the rest of the community through the implementation of several mechanism, among which outstands, first, the proposal of a major north-south midblock passage and a 1.5-acre open space between West 130th and 131st Streets, \”where people can meet and relax in an outdoor setting\”, and second, the use of glass as the primary building material at the street level (quote) \”to create a feeling of transparency allowing pedestrians to see into and around the corners of buildings and contributing to a safe and open environment.\”_PROBLEMThe Studio will look at Columbia\'s University West Harlem expansion as the area of inquiry and analyses. Columbia\'s need for physical expansion and its program of requirements will be taken as point of departure. Despite the fact that we will look at the whole site under development in order to establish alternative frameworks of approach and analysis, the specific proposals will be limited to the block between West 130th and 131st Streets, where a major open space has to be allocated.The normative quality of the program -laboratories and classrooms-, its repetitive pattern of useable, flexible and inconspicuous space, on the one hand, and the imprecise and undefined open and accessible areas, -loose, framed or interstitial-, on the other, compose the two extremes in a wide range of possibilities within a disciplinary approach to a site that calls for a social space as its most fundamental feature.Confronting the existent with the proposed -admitting both as possible options to work with-, we shall look at the potential transformations of the area attending at the number of factors that convey on it: the nature of the institution and its academic prestige, the social implications of the new, the instrumentality of architecture and the potential description of the public realm and the plural space.Despite the normative search for phenomenological synthesis, architecture cannot hide the unequivocal traces of the conflicts that underlay the appearance of things. The roll performed by these \”privately owned, publicly accessible space\”, central to the development as a negotiating device, exposes its paradoxical nature. However unprogramed, unbounded and undefined, it shall be considered as the symptom and proof of what architecture is capable of represent and accomplish. Our interest resides on the instrumental use of architecture as negotiating ground where to expose and conceal at the time the friction among the different layers overlapped (social, political, communal, programmatic, legal, phycological or aesthetic).