Wall signs. Permanent wall signs shall be attached to a wall with non-rusting metal hardware. The maximum vertical dimension for a permanent wall sign shall be two feet, except that the maximum vertical dimension for a permanent wall sign on a building fronting on Route 57, Route 519, or Route 22 shall be four feet. Permanent wall signs in multi-tenant buildings and shopping centers shall maintain a consistent design theme by their arrangement in an aesthetically compatible and visually coordinated manner, and shall be of a uniform height above grade. Permanent or temporary walls signs shall be positioned so as not to interrupt architectural details.