Permitted obstructions in required yards, courts and open space
(a) For single- and two-family residences, where flood-resistant construction elevation is five feet or more above curb level, roofed porches shall be permitted obstructions in any open space required on the zoning lot and in yards. Balconies for such residences may exceed the width and depth standards of Section 23-13 where such balconies are located directly above a porch.
(b) For single- and two-family residences, lifts for persons with disabilities shall be permitted obstructions in any open space required on the zoning lot and in courts, yards and rear yard equivalents, provided that in front yards, such lifts are unenclosed.
(c) For all buildings, except single- and two-family residences, accessory mechanical equipment shall be a permitted obstruction in rear yards and rear yard equivalents, provided that such equipment is:
(1) located above flood-resistant construction elevation;
(2) enclosed within a building, or portion thereof, or within a structure that provides screening of such mechanical equipment on all sides by walls consisting of at least 50 percent opaque materials;
(3) in R3, R4 or R5 Districts, limited to a height of 10 feet above flood-resistant construction elevation, including the apex of a pitched roof;
(4) in R6, R7, R8, R9 or R10 Districts, limited to a height of 14 feet above flood-resistant construction elevation; or
(5) in Commercial or Manufacturing Districts, limited to a height of 23 feet above flood-resistant construction elevation.
Accessory mechanical equipment located in rear yards or rear yard equivalents and meeting the standards of this Section shall be a permitted obstruction in any open space required on the zoning lot, provided that the total area occupied by a building used for both enclosed parking and such mechanical equipment does not exceed 20 percent of the total required open space on the zoning lot.
Decks, parapet walls, roof thickness, skylights, vegetated roofs, and weirs, as set forth in Section 23-62 (Permitted Obstructions), and solar energy systems, limited to 18 inches in height, as measured perpendicular to the roof surface, shall be permitted upon the roof of such accessory building within the rear yard or rear yard equivalent.