How do you make nothing? This is the question the architect Josep Lluis Mateo faced in designing the Barcelona Forum Convention Center. Faced with the prospect of giving form to an in essence meaningless and elusive program on a vast scale, Josep Lluis Mateo has answered with voids. He has made a building that composes empty spaces ranging in scale from the immense to the almost intimate into a coherent and urbane structure. The resulting complex of large rooms is not so much an object as an urban collage clothing this amalgamation of nothing, integrating it both into the life of the city of Barcelona and making it into a giant tent in which the urban nomads who will inhabit this structure will feel at home.