Is five or six stories just too high for a Darien building, even downtown? Or will those buildings loom less over downtown and nearby homes than some fear? Those questions were behind a lot of the discussion Tuesday night at the Planning & Zoning Commission’s last public hearing on a zoning change proposal that would allow higher structures on the triangular site bounded by Corbin Drive, the Post Road and Interstate 95. In a slide presentation from developer David Genovese and his team, the commission saw sketches showing how high the buildings would appear from various angles downtown, some as far away as Darien Library and the intersection of Brookside Road and the Post Road. The commission members also asked questions about how much height was needed for multi-story buildings, how many parking spaces would be provided.