13-56-240 Mixed occupancy – Defined.

   A building designed or used for two or more occupancies, representing different occupancy classifications, except in the case of auxiliary uses as described in Section 13-56-250, shall be classified as a mixed occupancy.

(Prior code § 48-12)

13-56-250 Auxiliary uses.

   Rooms and spaces normally provided and incidental to the principal use of a building and under the same management and control shall be classified as auxiliary uses and shall not be considered as constituting a mixed occupancy.

   Auxiliary uses shall not introduce any unusual hazard or danger unless in the judgment of the building commissioner such auxiliary use is indispensable to the principal use.

   Auxiliary uses, other than legal home occupations licensed under Section 4-6-270, shall be limited to a maximum of five percent of the area occupied by the principal use, provided however, that the building commissioner and the fire commissioner may jointly approve auxiliary uses exceeding said five percent of the area of the principal use when in their opinion such auxiliary uses do not unduly increase the hazards. A legal home occupation licensed in accordance with Section 4-6-270 shall not permanently occupy more than ten percent of the floor area of any single-family residence or 15 percent of the floor area of any unit in a multiple dwelling building; provided, however, that in no instance may one or more home occupations in any single dwelling unit permanently occupy more than 300 square feet of the dwelling unit.

   Loading spaces and appurtenant driveways extending more than five feet into a building or structure when used by vehicles with internal combustion engines on any street level floor within industrial units and storage units one story in height, shall be limited to 20 percent of the floor area of the principal use, and shall be separated from the principal use by a loading platform, curb, railing or other fixed barricade. The vehicles with internal combustion engines using such loading spaces and appurtenant driveways shall not remain inside the building for a longer period than necessary for loading or unloading and while inside the building shall at all times be under control of the driver.

   Spaces classified as auxiliary uses shall comply with the applicable requirements of this Code pertaining to the specific use but not require the special separations as established in Section 13-56-280 and shall not govern height or area limitations as established for the principal occupancy of the building.

(Prior code § 48-12.2; Amend Coun. J. 9-13-89, p. 4604; Amend Coun. J. 4-1-98, p. 65910 § 6; Amend Coun. J. 3-5-03, p. 104990, § 21; Amend Coun. J. 11-13-07, p. 14999, Art. II, § 1; Amend Coun. J. 5-9-12, p. 27485, § 174)

 

Notes

4-6-270

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13-56-260 Mixed occupancy – Applicable provisions.

   When a building is occupied by two or more occupancies not included in one classification, the provisions of this Code applying to each use shall apply to such parts of the building as come within that classification.

(Prior code § 48-12.3)

13-56-270 Mixed occupancy – Height and area limitations.

   Height and area limitations in buildings of mixed occupancy shall comply with the requirements of Section 13-48-100.

(Prior code § 48-12.4)

13-56-280 Mixed occupancy – Fire-resistive separations required.

   Each occupancy in a building of mixed occupancy shall be separated horizontally and vertically from any adjoining occupancy by construction materials providing fire resistance as established in Table 13-56-280 as set out in this section. Separation between Type III schools and A, B, C-1, C-2, and E occupancies, except day care centers with children less than two years of age, may be reduced to one hour. Separation between Type III schools with children less than two years of age and A, B, C-2, E and F occupancies may be reduced to two hours.

   Separation in buildings of mixed occupancies may be reduced by one hour from the fire resistance requirements as established in Table 13-56-280 as set out in this section when the building is equipped throughout with an approved automatic sprinkler system which is supervised except that separations between day care centers with children less than two years of age and A, B, C, C-1, C-2, E and F occupancies shall not be reduced to less than two hours.

(Prior code § 48-12.5; Amend Coun. J. 9-13-89, p. 4604; Amend Coun. J. 7-14-93, p. 35324; Amend Coun. J. 10-30-96, p. 31214)

Table 13-56-280 REQUIRED SEPARATIONS IN BUILDINGS OF MIXED OCCUPANCY Fire Resistive Ratings in Hours
Occupancy Classification		A	B	C-1	C-2	C-3	D	E	F	G	H-1 H-2	H-3	I
A.	Residential		3	4	2	4	4	1(d)	1	4	4	4	(b)
B.	Institutional	3		4	4	3	4	4	4(c)	(b)	4(c)	4(c)	(b)
C-1.	Large assembly	4	4		4	4	4	4	4	4(c)	4(c)	4(c)	(b)
C-2.	Small assembly	2	4	4		4	2	2(d)	2	4	4	4	(b)
C-3.	Schools	4	3	4	4	(e)	4	2(d)	4	4(c)	4(c)	4(c)	(b)
D.	Open air assembly	4	4	4	2	4		4	4	4	4	4	(b)
E.	Business	1(d)	4	4	2(d)	2(d)	4(d)	(d)	(a)(d)	(a)(d)	(a)(d)	2(d)	4
F.	Mercantile	1	4(c)	4	2	4	4	(a)		3	(a)	3	(b)
G.	Industrial	4	(b)	4(c)	4	4(c)	4	(a)(d)	3		(a)	4	4
H-1 & H-2.	Storage	4	4(c)	4(c)	4	4(c)	4	(a)(d)	(a)	(a)		4	4
H-3.	Garages	4	4(c)	4(c)	4	(c)	4	2(d)	3	4	4		4
I.	Hazardous use	(b)	(b)	(b)	(b)	(b)	(b)	4(d)	(b)	4	4	4
(a)   No special separation required. (b)   Mixed occupancy not permitted. (c)   Unpierced separations. (d)   A technology center shall have a minimum two-hour separation from all other occupancies including other business occupancies, regardless whether the subject building is protected by a sprinkler system. (e)   For trade or technical schools, shop portions of schools may be built to comply with requirements for industrial buildings, but shall have four-hour fire separations with double Class A fire doors between shop portions and academic portions of buildings.

 

(Added Coun. J. 6-28-00, p. 36679, § 5)

13-56-290 Separation from public spaces below grade.

   (a)   The interior of any building which adjoins a subway or other public space below grade not open to the sky, shall be separated from subway or other public space by walls or floors of solid masonry or reinforced concrete, or equal with a fire-resistive rating of not less than four hours.

   (b)   Every opening through a wall, required by this section to be used as an exit, shall be protected by a labeled outswinging Class A fire door. Such doors shall be equipped with approved panic hardware and may be single or pairs. Every other opening through such wall, not required as an exit shall be protected with a Class A fire door.

   (c)   No wall used in a separation required by this section shall be located more than twenty feet back from the subway or other public space. Show windows and display spaces may be located on the public side of such separating wall, but there shall not be more than one door opening into each show window or display space.

   (d)   Nothing in this section shall be construed to prevent the entire space under any building or any portion of such space, or any passage through a building from being used as a right-of-way or switching space for railroads or public carriers; provided, however, that such spaces or passages shall not be designed or used as a public thoroughfare nor as a parking space for motor vehicles where such use is prohibited by other sections of this Code; and provided further, that such space is separated from the interior and adjacent parts of the building as required by this section for subways.

(Prior code § 48-12.6)

13-56-300 Occupancy content determination.

   When the requirements of this Code are related to the maximum number of persons occupying a space or building such occupancy content shall be determined as provided in Sections 13-56-310 and 13-56-320.

(Prior code § 48-13)