Permitted obstructions in required yards

In all Commercial, Manufacturing, and Mixed Use Districts, the permitted obstruction provisions of paragraph (b)(3) of Section 33-23 and paragraph (b)(1) of Section 43-23 shall be modified such that, in any rear yard, any building or portion of a building used for any permitted non-residential use (except any building portion containing rooms used for living or sleeping purposes) shall be a permitted obstruction, provided that the height of such building, or portion thereof, shall not exceed two stories, excluding basements, nor in any event 30 feet above curb level.