Manhattan contractors are used to building in small spaces. But when an owner-developer joint venture team offered to custom-design a 24-story tower for Pace University housing at 180 Broadway, the idea of "small spaces" took on a new dimension. The $60-million project is in a particularly congested part of the city—and within two blocks of five other major construction jobs, including the World Trade Center redevelopment and the Fulton Street Transit Center, which is across the street.