64-32 Special Yard Regulations
The provisions of this Section shall apply without requiring a building to comply with flood-resistant construction standards as established in paragraph (a) of Section 64-12 (Applicability).
Underlying yard regulations shall be modified to allow yards to be higher than curb level but in no event higher than flood-resistant construction elevation. In addition, the following regulations shall apply:
(a) in Residence Districts and C1 through C6 Districts, yards higher than curb level shall comply with the following standards:
(1) final grade shall not penetrate a plane that begins 30 inches above curb level at each lot line and has a slope extending perpendicular to lot lines of one foot vertical for each 2.5 feet horizontal;
(2) retaining walls shall be permitted above curb level in yards provided the maximum height of each wall above adjacent grade does not exceed 30 inches; and
(3) in front yards in Residence Districts, portions of fences greater than four feet above curb level shall be required to be no more than 50 percent opaque; and
(b) in C7 and C8 Districts and in Manufacturing Districts, yards shall be permitted to a maximum grade equal to flood-resistant construction elevation. However, for portions of zoning lots where Sections 33-29 and 43-30 (SPECIAL PROVISIONS APPLYING ALONG DISTRICT BOUNDARIES) apply, yards are permitted above curb level only pursuant to paragraph (a) of this Section.
Nothing in this Section shall be construed so as to permit the creation of spaces sub-grade on all sides in a manner inconsistent with Appendix G of the Building Code.
(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.
Temporary flood control devices and associated emergency egress systems that are assembled prior to a storm and removed thereafter shall be permitted obstructions in yards and rear yard equivalents, courts, open space, waterfront yards as defined in Article VI, Chapter 2, public plazas and all other publicly accessible open areas during such storm event and for a reasonable period prior to and after such storm event, as determined by the Department of Buildings.