One or the other or both should apply here UPC 906.1 Each vent pipe or stack shall extend through its flashing and shall terminate vertically not less than six (6) inches (152 mm) above the roof nor less than one (1) foot (305 mm) from any vertical surface. or 906.2 Each vent shall terminate not less than ten (10) feet (3048 mm) from, or at least three (3) feet (914 mm) above, any openable window, door, opening, air intake, or vent shaft, nor less than three (3) feet (914 mm) in every direction from any lot line-alley and street excepted. Bill, some areas do not allow for AAV's to be used. Here in St. Louis city they do not allow them to be used but other municipalities do.