64-30 Special Bulk Regulations
For single- and two-family residences with enclosed entryways below flood-resistant construction elevation, up to 10 square feet of such entryway may be excluded from the definition of floor area for each foot of difference between the lowest occupiable floor and curb level. This area may be excluded from the definition of floor area provided it is not greater than the total area of ramps, stairs, lifts and elevators between grade and the first finished floor, plus an initial entry area of no more than 12 square feet.
For all buildings other than single- and two-family residences, with enclosed publicly accessible entryways below flood-resistant construction elevation, up to 100 square feet of such entryways may be excluded from the definition of floor area for each foot of difference between the lowest occupiable floor and curb level. This area may be excluded from the definition of floor area provided it is not greater than the total area at each publicly accessible entryway of ramps, stairs, lifts and elevators plus an initial entry area of no more than 100 square feet for each entryway.
Floor space used for accessory mechanical equipment in R1-2A, R2A, R2X, R3, R4 or R5 Districts may be excluded from the definition of floor area without the limitations provided in the definition of floor area, paragraphs (m) and (8) in Section 12-10 (DEFINITIONS).
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.
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).
In R3-2 and R4 Districts, for all buildings, or portions thereof, subject to Section 23-60 (HEIGHT AND SETBACK REGULATIONS), except single- and two-family residences, elevator or stair bulkheads (including shafts, and vestibules not larger than 60 square feet in area providing access to a roof), roof water tanks and accessory mechanical equipment (including enclosures), other than solar or wind energy systems, shall be considered permitted obstructions to height and setback regulations, provided that:
(a) such obstructions shall be located not less than 10 feet from the street wall of a building;
(b) all mechanical equipment shall be screened on all sides;
(c) the lot coverage of all such obstructions and screening does not exceed 250 square feet or 10 percent of the lot coverage of the building, whichever is greater; and
(d) such obstructions are limited to a height of 15 feet above the maximum height of perimeter walls.
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).
In R5 through R10 Districts, and in all Commercial and Manufacturing Districts, for all buildings, the underlying regulations governing permitted obstructions to height and setback shall be modified to increase the permitted volume for elevator or stair bulkheads (including shafts, and vestibules not larger than 60 square feet in area providing access to a roof), roof water tanks and accessory mechanical equipment (including enclosures), other than solar or wind energy systems, from a maximum lot coverage of 20 percent of the lot coverage of the building to a maximum lot coverage of 30 percent of the lot coverage of the building, provided that where the maximum permitted height of a building is less than 120 feet, such obstructions are limited to a maximum height of 25 feet, and where the maximum permitted height of a building is 120 feet or greater, such obstructions are limited to a maximum height of 40 feet.
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).
In all districts, where underlying street wall location regulations require the ground floor of a street wall to extend along the entire street frontage of a zoning lot and be located on the street line, such regulations are modified as follows:
(a) recesses, not to exceed five feet in depth from the street line, shall be permitted on the ground floor where required to provide access to the building; and
(b) up to 30 percent of the aggregate width of street walls may be recessed beyond the street line, provided any such recesses deeper than 10 feet along a wide street, or 15 feet along a narrow street, are located within an outer court. However, no recesses shall be permitted within 30 feet of the intersection of two street lines.
R1 R2 R3 R4 R5
In the districts indicated, as an alternative to Section 64-131 (Measurement of height), for single- and two-family residences where flood-resistant construction elevation is between six and nine feet above curb level, building height may be measured from a reference plane nine feet above curb level, provided that at least two mitigating elements are provided from the list in Section 64-61 (Design Requirements for Single- and Two-family Residences).
R1 R2 R3 R4 R5 R6 R7 R8 R9 R10
In the districts indicated, as an alternative to Section 64-131 (Measurement of height), for all buildings other than single- and two-family residences, where flood-resistant construction elevation is between five and 10 feet above curb level, building height may be measured from a reference plane 10 feet above curb level, and any minimum base height requirements may be measured from curb level. Where the provisions of this Section are utilized, the standards of Section 64-622 (Lobby or non-residential use) shall be met.
C1 C2 C3 C4 C5 C6
(a) In the districts indicated, as an alternative to Section 64-131 (Measurement of height), for all residential buildings other than single- and two-family residences, where flood-resistant construction elevation is between five and 10 feet above curb level, building height may be measured from a reference plane 10 feet above curb level, and any minimum base height requirements may be measured from curb level. Where the provisions of this Section are utilized, the standards of Section 64-622 (Lobby or non-residential use) shall be met.
C1 C2 C3 C4 C5 C6 C7 C8 M1 M2 M3
(b) In the districts indicated, as an alternative to Section 64-131, for all buildings other than residential buildings and buildings containing predominantly Use Group 16, 17 or 18 uses, where street walls are within 50 feet of a street line and flood-resistant construction elevation is between five and 12 feet above curb level, building height may be measured from a reference plane 12 feet above curb level, and any minimum base height requirements may be measured from curb level. Where the provisions of this Section are utilized, the standards of Section 64-642 (Transparency requirements for buildings utilizing alternative height measurement) shall be met.