CHAPTER 14B-5
GENERAL BUILDING HEIGHTS AND AREAS

14B-5-501   General.

14B-5-502   Building address.

14B-5-503   General building height and area limitations.

14B-5-504   Building height and number of stories.

14B-5-505   Mezzanines and equipment platforms.

14B-5-506   Building area.

14B-5-507   IBC Section 507.

14B-5-508   Mixed use and occupancy.

14B-5-509   Incidental uses.

14B-5-510   IBC Section 510.

14B-5-501 General.

The provisions of Section 501 of IBC are adopted by reference with the following modification:

1.   Revise Section 501.1 by adding a second paragraph to read:

"Nothing in this chapter shall be interpreted to prevent the application of other limitations provided by the Chicago Zoning Ordinance."

14B-5-502 Building address.

The provisions of Section 502 of IBC are adopted by reference with the following modification:

1.   Revise Section 502.1 to read:

"502.1 Address identification.

Address identification shall be provided in accordance with Chapter 10-4 of the Municipal Code."

14B-5-503 General building height and area limitations.

The provisions of Section 503 of IBC are adopted by reference with the following modifications:

1.   Revise Section 503.1 to read:

"503.1 General.

Unless otherwise specifically modified in Chapter 4 and this chapter, building height, number of stories above grade plane and building area shall not exceed the limits specified in Sections 504 and 506 based on the type of construction as determined by Section 602 and the occupancies as determined by Section 302 except as modified hereafter. Building height, number of stories above grade plane and building area provisions shall be applied independently. For the purposes of determining building area limitations, building height limitations and type of construction, each portion of a structure separated by one or more fire walls complying with Section 706 shall be considered to be a separate building."

2.   Revise Section 503.1.1 to read:

"503.1.1 Special industrial occupancies.

Single-story buildings and structures of Type I or II construction used exclusively for the production and distribution of electricity, gas or steam or for low-hazard industrial processes that require large areas and unusual building heights to accommodate craneways or special machinery and equipment shall be exempt from the building height and building area limitations specified in Sections 504 and 506."

3.   Revise Section 503.1.2 to read:

"503.1.2 Buildings on same lot.

Two or more buildings on the same lot shall be regulated as separate buildings.

Exception: Two or more buildings on the same lot of record may be considered as portions of one building where the building height and number of stories above grade plane of each building and the aggregate building area of the buildings are within the limitations specified in Sections 504 and 506. The provisions of this code applicable to the aggregate building shall be applicable to each building."

4.   Delete Section 503.1.3.

5.   Revise Section 503.1.4 and its subsections to read:

"503.1.4 Occupiable rooftops.

A roof level or portion thereof shall be permitted to be used as an occupiable rooftop provided the occupancy of the roof is an occupancy that is permitted by Table 504.4 for the story immediately below the roof. The area of the occupiable rooftop shall not be included in the building area as regulated by Section 506.

Exception: The occupancy located on an occupiable rooftop shall not be limited to the occupancies allowed on the story immediately below the occupiable rooftop where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and occupant notification in accordance with Section 907.5 is provided in the area of the occupiable rooftop."

(Amend Coun. J. 2-19-20, p. 14473, Art. II, § 15)

14B-5-504 Building height and number of stories.

The provisions of Section 504 of IBC are adopted by reference with the following modifications:

1.   Revise Section 504.1, excluding the exception, to read:

"504.1 General.

The allowable building height, in feet, and the allowable number of stories above grade plane of a building shall be determined based on the type of construction, occupancy classification and whether there is an automatic sprinkler system installed throughout the building."

2.   Delete Section 504.1.1.

3.   Delete Section 504.1.2.

4.   Revise Section 504.3 to read:

"504.3 Height in feet.

The maximum building height, in feet, of a building shall not exceed the limits specified in Table 504.3.

Exception: Towers, spires, minarets, steeples and other rooftop structures with a footprint not exceeding 25 percent of the ground area of the building on which they are erected shall be constructed of materials consistent with the required type of construction of the building except where other construction is permitted by Section 1510.2.4. Such rooftop structures shall not be used for habitation or storage. The rooftop structures shall not extend more than 60 feet (18.3 m) above the allowable building height where of noncombustible materials and shall not extend more than 20 feet (6096 mm) above the allowable building height where of combustible materials (see Chapter 15 for additional requirements)."

5.   Replace Table 504.3 as shown:

TABLE 504.3
ALLOWABLE BUILDING HEIGHT IN FEET ABOVE GRADE PLANE a

OCCUPANCY CLASSIFICATION	TYPE OF CONSTRUCTION
	SEE FOOTNOTES	TYPE I		TYPE II		TYPE III		TYPE IV	TYPE V
		A	B	A	B	A	B	HT	A	B
A, B, E, F, H-4 c, M, S, U	NS b	80	80	65	30	55	30	65	30	15
	S	UL	150	85	45	70	45	85 g	45	30
H-1, H-2, H-3, H-5	NS c, d	80	80	65	30	55	NP	65	NP	NP
	S	UL
I	NS b	80	80	65	30	55	30	65	30	NP
	S	UL	150	85
R	NS b	80	80	65	30	55	30	65	30 e	20
	S13D	40	40	40	40	40	40	40	40	35
	S13R	55	55	55	45	55	45	55	45 f	35
	S	UL	150	85	45	70	45	85 g	45 f	35

 

For SI: 1 foot = 304.8 mm.

UL   =   Unlimited.

NS   =   Buildings not equipped throughout with an automatic sprinkler system.

S   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

S13R   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.

S13D   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.

a.   See Chapters 4 and 5 for specific exceptions to the allowable building height in this table.

b.   See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.

c.   New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.

d.   The NS value is only for use in evaluation of existing buildings in accordance with the Chicago Building Rehabilitation Code.

e.   Group R occupancies of Type VA construction shall be allowed to be 40 feet in building height, provided that the finished floor level of the highest occupiable space shall not exceed 30 feet above grade plane.

f.   Group R occupancies of Type VA construction equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 shall be allowed to be 55 feet in building height, provided that the finished floor level of the highest occupiable space shall not exceed 40 feet above grade plane.

g.   120 feet for evaluation of buildings constructed or permitted for construction before January 1, 1951, that are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.

6.   Revise Section 504.4 to read:

"504.4 Number of stories above grade plane.

The maximum number of stories above grade plane of a building shall not exceed the limits specified in Table 504.4."

7.   Replace Table 504.4 as shown:

TABLE 504.4
ALLOWABLE NUMBER OF STORIES ABOVE GRADE PLANE a, b

OCCUPANCY CLASSIFICATION	SEE NOTES	TYPE OF CONSTRUCTION
		TYPE I		TYPE II		TYPE III		TYPE IV	TYPE V
		A	B	A	B	A	B	HT	A	B
A-1	NS	UL	5	3	1	2	NP	2	1	NP
	S-13	UL	6	4	2	3	1	3	1	NP
A-2	NS	UL	10	3	1	2	NP	2	1	NP
	S-13	UL	11	4	2	3	1	3	1	NP
A-3	NS	UL	10	3	1	2	NP	2	1	NP
	S-13	UL	11	4	2	3	1	3	1	NP
A-4	NS	UL	10	3	1	2	NP	2	1	NP
	S-13	UL	11	4	2	3	1	3	1	NP
A-5	NS	UL	UL	UL	UL	1	1	UL	1	1
	S-13	UL	UL	UL	UL	1	1	UL	1	1
B	NS	UL	11	6	1	4	2	5	1	NP
	S-13	UL	12	7	2	5	3	6	2	1
E-1	NS	UL	5	3	1	1	1	1	1	NP
	S-13	UL	6	4	1	2	1	2	1	NP
E-2	NS	UL	5	3	1	1	1	1	1	NP
	S-13	UL	6	4	1	2	1	2	1	NP
F-1	NS	UL	5	4	1	3	2	4	1	1
	S-13	UL	6	5	2	4	3	5	1	1
F-2	NS	UL	5	4	1	3	2	4	1	1
	S-13	UL	6	5	2	4	3	5	1	1
H-1	NS c, d	1	1	1	1	1	1	1	1	NP
	S-13	1	1	1	1	1	1	1	1	NP
H-2	NS c, d	UL	3	2	1	2	1	1	NP	NP
	S-13	UL	3	2	1	2	1	1	NP	NP
H-3	NS c, d	UL	5	3	1	3	2	3	NP	NP
	S-13	UL	5	3	1	3	2	3	NP	NP
H-4	NS c, d	UL	5	4	1	3	2	4	1	NP
	S-13	UL	6	5	1	4	3	5	1	NP
H-5	NS c, d	4	4	3	1	3	2	3	NP	NP
	S-13	4	4	3	1	3	2	3	NP	NP
I-1, Condition 1	NS d, e	UL	9	3	1	2	1	2	1	NP
	S-13	UL	10	4	2	3	1	3	1	NP
I-1, Condition 2	NS d, e	UL	4	3	1	1	NP	1	1	NP
	S-13	UL	5	4	1	1	NP	1	1	NP
I-2, Condition 1	NS f	UL	4	3	1	1	NP	1	1	NP
	S-13	UL	5	4	1	1	NP	1	1	NP
I-2, Condition 2	NS f	UL	4	3	1	1	NP	1	1	NP
	S-13	UL	5	4	1	1	NP	1	1	NP
I-3	NS d, e	UL	9	2	1	1	NP	1	1	NP
	S-13	UL	10	3	1	1	NP	1	1	NP
I-4	NS	UL	9	3	1	1	NP	1	1	NP
	S-13 d, g	UL	10	4	1	2	NP	3	1	NP
M	NS	UL	11	6	1	4	2	5	1	NP
	S-13	UL	12	7	2	5	3	6	1	1
R-1 h	NS d	UL	11	4	1	4	2	4	2	1
	S-13R	4	4	4	2	4	2	4	2	1
	S-13	UL	12	6	2	5	3	5	3	2
R-2	NS	UL	11	4	1	4	2	4	2	1
	S-13R	4	4	4	2	4	3	4	4	2
	S-13	UL	12	6	2	5	3	5	4	2
R-3 h	NS	UL	11	4	1	4	2	4	2	1
	S-13D	3	3	3	2	3	2	3	3	2
	S-13R	4	4	4	2	4	3	4	4	2
	S-13	UL	12	6	2	5	3	5	4	2
R-4 h	NS d	UL	11	4	1	4	2	4	NP	NP
	S-13D	3	3	3	2	3	2	3	3	2
	S-13R	4	4	4	2	4	3	4	3	2
	S-13	UL	12	6	2	5	3	5	3	2
R-5	NS	UL	11	4	1	4	3	4	3	2
	S-13D	3	3	3	3	3	3	3	3	2
	S-13R	4	4	4	3	4	3	4	4	2
	S-13	UL	12	6	3	5	3	5	4	2
S-1	NS	UL	5	4	1	3	2	5	1	1
	S-13	UL	6	5	2	4	3	6	1	1
S-2	NS	UL	5	4	1	3	2	5	1	1
	S-13	UL	6	5	2	4	3	6	1	1
U	NS	UL	5	4	1	3	2	4	1	1
	S-13	UL	6	5	1	4	3	5	1	1

 

UL   =   Unlimited.

NP   =   Not permitted.

NS   =   Buildings not equipped throughout with an automatic sprinkler system.

S   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

S13R   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.

S13D   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.

a.   See Chapters 4 and 5 for specific exceptions to the allowable number of stories above grade plane in this table.

b.   See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.

c.   New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.

d.   The NS value is only for use in evaluation of existing buildings in accordance with the Chicago Building Rehabilitation Code.

e.   New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies, Condition 1, see Exception 1 of Section 903.2.6.

f.   New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and the Chicago Minimum Requirements for Existing Buildings.

g.   For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.

h.   New Group R-1, R-3 and R-4 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.

(Amend Coun. J. 7-24-19, p. 3646, §§ 28, 29; Amend Coun. J. 2-19-20, p. 14473, Art. II, § 16; Amend Coun. J. 6-25-21, p. 32180, Art. II, § 5; Amend Coun. J. 1-26-22, p. 43756, Art. II, § 4)

14B-5-505 Mezzanines and equipment platforms.

The provisions of Section 505 of IBC are adopted by reference with the following modifications:

1.   Revise Section 505.2 to read:

"505.2 Mezzanines.

A mezzanine or mezzanines in compliance with Section 505.2 shall be considered a portion of the story below. Such mezzanines shall not contribute to the number of stories above grade plane as regulated by Section 503.1. The area of the mezzanine shall be included in determining the building area and the fire area. The clear height above and below the mezzanine floor construction shall be not less than 7 feet (2134 mm)."

2.   Revise Section 505.2.1 to read:

"505.2.1 Area limitation.

The aggregate area of a mezzanine or mezzanines within a room shall be not greater than twenty percent of the floor area of that room or space in which they are located. The enclosed portion of a room shall not be included in a determination of the floor area of the room in which the mezzanine is located. In determining the allowable mezzanine area, the area of the mezzanine shall not be included in the floor area of the room.

Exceptions:

1.   The aggregate area of mezzanines in buildings of Type I or II construction for special industrial occupancies in accordance with Section 503.1.1 shall be not greater than two-thirds of the floor area of the room.

2.   [Reserved.]

3.   The aggregate area of a mezzanine within a dwelling unit that is located in a building equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 shall not be greater than one-half of the floor area of the room, provided that both:

3.1.   Except for enclosed closets and bathrooms, the mezzanine shall be open to the room in which such mezzanine is located.

3.2.   The opening to the room shall be unobstructed except for walls not more than 48 inches (1219 mm) in height, columns and posts."

3.   Revise Section 505.2.1.1 by replacing "two-thirds" with "one-half."

4.   Revise the exceptions to Section 505.2.3 to read:

"1.   In Group B, F, M and S occupancies in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the occupant load of the aggregate area of the enclosed space is not greater than 10.

2.   [Reserved.]

3.   Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located provided that the aggregate floor area of the enclosed space is not greater than 10 percent of the allowable mezzanine area.

4.   In industrial facilities, mezzanines used for control equipment are permitted to be glazed on all sides.

5.   [Reserved.]

6.   Mezzanines in accordance with Exception 3 to Section 505.2.1."

5.   Revise Section 505.3 by replacing "stories" with "stories above grade plane."

6.   Revise Section 505.3.1 by replacing "two-thirds" with "one-half."

(Amend Coun. J. 2-19-20, p. 14473, Art. II, § 17)

14B-5-506 Building area.

The provisions of Section 506 of IBC are adopted by reference with the following modifications:

1.   Revise Section 506.1 and its subsections to read:

"506.1 General.

The allowable building area of a building shall be determined based on the type of construction, occupancy classification, whether there is an automatic sprinkler system installed throughout the building and the amount of building frontage on a public way or yard.

506.1.1 [Reserved.]

506.1.2 [Reserved.]

506.1.3 Basements.

Basements shall be included in building area where the total area of such basements exceeds the allowable building area for a one-story above grade plane building of the same occupancy and construction type.

506.1.3.1 Maximum area.

Every basement exceeding 40,000 square feet (3716 m2) in area shall be subdivided by fire barriers into areas not exceeding 40,000 square feet (3716 m2), provided where the building is equipped throughout with an automatic sprinkler system, the maximum undivided area may be increased to 80,000 square feet (7432 m2)."

2.   Replace Table 506.2 as shown:

TABLE 506.2
ALLOWABLE AREA FACTOR (At = NS, S1, S13R, S13D or SM, as applicable) IN SQUARE FEET a, b

OCCUPANCY CLASSIFICATION	SEE NOTES	CONSTRUCTION TYPE
		TYPE I		TYPE II		TYPE III		TYPE IV	TYPE V
		A	B	A	B	A	B	HT	A	B
A-1	NS	UL	UL	16,000	8,500	6,000	NP	6,000	3,000	NP
	S1	UL	UL	64,000	34,000	24,000	12,000	24,000	12,000	NP
	SM	UL	UL	48,000	25,500	18,000	9,000	18,000	9,000	NP
A-2	NS	UL	UL	16,000	8,500	6,000	5,000	6,000	3,000	NP
	S1	UL	UL	64,000	34,000	24,000	20,000	24,000	12,000	NP
	SM	UL	UL	48,000	25,500	18,000	15,000	18,000	9,000	NP
A-3	NS	UL	UL	16,000	8,500	6,000	5,000	6,000	3,000	NP
	S1	UL	UL	64,000	34,000	24,000	20,000	24,000	12,000	NP
	SM	UL	UL	48,000	25,500	18,000	15,000	18,000	9,000	NP
A-4	NS	UL	UL	16,000	8,500	6,000	5,000	6,000	3,000	NP
	S1	UL	UL	64,000	34,000	24,000	20,000	24,000	12,000	NP
	SM	UL	UL	48,000	25,500	18,000	15,000	18,000	9,000	NP
A-5	NS	UL	UL	UL	UL	UL	UL	UL	UL	UL
	S1	UL
	SM	UL
B	NS	UL	UL	20,000	6,000	10,000	8,000	10,000	6,000	4,000
	S1	UL	UL	UL	UL	UL	32,000	40,000	24,000	16,000
	SM	UL	UL	60,000	18,000	30,000	24,000	30,000	18,000	NP
E-1	NS	UL	UL	16,000	5,000	8,000	3,000	10,000	3,000	NP
	S1	UL	UL	64,000	20,000	32,000	12,000	40,000	12,000	NP
	SM	UL	UL	48,000	15,000	24,000	9,000	30,000	9,000	NP
E-2	NS	UL	UL	16,000	5,000	8,000	3,000	10,000	3,000	NP
	S1	UL	UL	64,000	20,000	32,000	12,000	40,000	12,000	NP
	SM	UL	UL	48,000	15,000	24,000	9,000	30,000	9,000	NP
F-1	NS	UL	UL	16,000	4,000	8,000	4,000	8,000	5,000	3,000
	S1	UL	UL	UL	UL	32,000	16,000	32,000	20,000	12,000
	SM	UL	UL	48,000	12,000	24,000	12,000	24,000	15,000	NP
F-2	NS	UL	UL	20,000	10,000	10,000	6,000	10,000	6,000	4,000
	S1	UL	UL	UL	UL	40,000	24,000	40,000	24,000	16,000
	SM	UL	UL	60,000	30,000	30,000	18,000	30,000	18,000	NP
H-1	NS c, d	21,000	16,500	11,000	6,000	9,500	5,000	10,500	5,000	NP
	S1	21,000	16,500	11,000	6,000	9,500	5,000	10,500	5,000	NP
	SM	NP	NP	NP	NP	NP	NP	NP	NP	NP
H-2	NS c, d	21,000	16,500	11,000	6,000	9,500	5,000	10,500	NP	NP
	S1	21,000	16,500	11,000	6,000	9,500	5,000	10,500	NP	NP
	SM	42,000	16,500	11,000	NP	9,500	NP	NP	NP	NP
H-3	NS c, d	UL	60,000	20,000	6,000	10,000	5,000	10,000	NP	NP
	S1	UL	60,000	20,000	6,000	10,000	5,000	10,000	NP	NP
	SM	UL	60,000	20,000	NP	10,000	5,000	10,000	NP	NP
H-4	NS c, d	UL	UL	20,000	6,000	10,000	8,000	10,000	6,000	NP
	S1	UL	UL	80,000	24,000	40,000	32,000	40,000	24,000	NP
	SM	UL	UL	60,000	NP	30,000	24,000	30,000	NP	NP
H-5	NS c, d	UL	UL	16,000	4,000	8,000	4,000	8,000	NP	NP
	S1	UL	UL	64,000	16,000	32,000	16,000	32,000	NP	NP
	SM	UL	UL	48,000	NP	24,000	12,000	24,000	NP	NP
I-1	NS d, e	UL	55,000	16,000	4,000	6,000	4,000	6,000	3,000	NP
	S1	UL	220,000	64,000	16,000	24,000	16,000	24,000	12,000	NP
	SM	UL	165,000	48,000	12,000	18,000	12,000	18,000	9,000	NP
I-2	NS d, f	UL	UL	12,000	6,000	6,000	NP	6,000	3,000	NP
	S1	UL	UL	48,000	24,000	24,000	NP	24,000	12,000	NP
	SM	UL	UL	36,000	NP	NP	NP	NP	9,000	NP
I-3	NS d, e	UL	UL	12,000	6,000	6,000	NP	6,000	3,000	NP
	S1	UL	UL	48,000	24,000	24,000	NP	24,000	12,000	NP
	SM	UL	UL	36,000	NP	NP	NP	NP	9,000	NP
I-4	NS d, g	UL	55,000	16,000	4,000	6,000	4,000	6,000	3,000	NP
	S1	UL	220,000	64,000	16,000	24,000	16,000	24,000	12,000	NP
	SM	UL	165,000	48,000	12,000	18,000	12,000	18,000	9,000	NP
M	NS	UL	UL	16,000	6,000	8,000	6,000	8,000	5,000	3,000
	S1	UL	UL	UL	UL	UL	24,000	32,000	20,000	12,000
	SM	UL	UL	48,000	18,000	24,000	18,000	24,000	15,000	NP
R-1 h	NS d	UL	UL	24,000	10,000	10,000	8,000	10,000	5,000	3,000
	S13R	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S1	UL	UL	96,000	40,000	40,000	32,000	40,000	20,000	12,000
	SM	UL	UL	72,000	30,000	30,000	24,000	30,000	15,000	9,000
R-2	NS	UL	UL	24,000	10,000	10,000	8,000	10,000	5,000	3,000
	S13R	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S1	UL	UL	96,000	40,000	40,000	32,000	40,000	20,000	12,000
	SM	UL	UL	72,000	30,000	30,000	24,000	30,000	15,000	9,000
R-3 h	NS	UL	UL	24,000	10,000	10,000	8,000	10,000	5,000	3,000
	S13D	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S13R	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S1	UL	UL	96,000	40,000	40,000	32,000	40,000	20,000	12,000
	SM	UL	UL	72,000	30,000	30,000	24,000	30,000	15,000	9,000
R-4 h	NS d	UL	UL	24,000	10,000	10,000	8,000	10,000	5,000	3,000
	S13D	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S13R	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S1	UL	UL	96,000	40,000	40,000	32,000	40,000	20,000	12,000
	SM	UL	UL	72,000	30,000	30,000	24,000	30,000	15,000	9,000
R-5	NS	UL	UL	24,000	10,000	10,000	8,000	10,000	5,000	3,000
	S13D	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S13R	UL	UL	48,000	20,000	20,000	16,000	20,000	10,000	6,000
	S1	UL	UL	96,000	40,000	40,000	32,000	40,000	20,000	12,000
	SM	UL	UL	72,000	30,000	30,000	24,000	30,000	15,000	9,000
S-1	NS	UL	35,500	19,000	8,500	14,000	8,000	18,000	5,000	3,000
	S1	UL	UL	UL	UL	56,000	32,000	72,000	20,000	12,000
	SM	UL	106,500	57,000	25,500	42,000	24,000	54,000	15,000	NP
S-2	NS	UL	79,000	28,500	13,000	21,000	10,000	27,000	6,000	4,000 i
	S1	UL	UL	UL	UL	84,000	40,000	108,000	24,000	16,000 i
	SM	UL	237,000	85,500	39,000	63,000	30,000	81,000	18,000	NP
U	NS	UL	30,000	16,000	6,000	8,000	6,000	8,000	5,000	1,000
	S1	UL	120,000	64,000	24,000	32,000	24,000	32,000	20,000	4,000
	SM	UL	90,000	48,000	18,000	24,000	18,000	24,000	15,000	NP

 

For SI: 1 square foot = 0.0929 m 2.

UL   =   Unlimited.

NP   =   Not permitted.

NS   =   Buildings not equipped throughout with an automatic sprinkler system.

S1   =   Buildings a maximum of one story above grade plane equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

SM   =   Buildings two or more stories above grade plane equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

S13R   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.

S13D   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.

a.   See Chapters 4 and 5 for specific exceptions to the allowable area factor in this table.

b.   See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.

c.   New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.

d.   The NS value is only for use in evaluation of existing buildings in accordance with the Chicago Building Rehabilitation Code.

e.   New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies, Condition 1, see Exception 1 of Section 903.2.6.

f.   New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the Chicago Fire Prevention Code.

g.   New Group I-4 occupancies see Exceptions 2 and 3 of Section 903.2.6.

h.   New Group R-1, R-3 and R-4 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.

i.   Type VB construction is not allowed for motor-vehicle-related occupancies other than private garages.

3.   Revise Equation 5-2 by deleting the second sentence from the description of Sa.

4.   Revise Section 506.2.4 to read:

"506.2.4 Mixed-occupancy, multistory buildings.

Each story of a mixed-occupancy building with more than one story above grade plane shall individually comply with the applicable requirements of Section 508.1. For buildings with more than three stories above grade plane, the building area shall be such that the aggregate sum of the ratios of the actual floor area of each story divided by the allowable area of such stories, determined in accordance with Equation 5-3 based on the applicable provisions of Section 508.1, shall not exceed three."

5.   Delete the exception to Section 506.2.4.

6.   Revise Section 506.3 to replace "public way" with "public way."

7.   Revise Section 506.3.1 to read:

"506.3.1 Minimum percentage of perimeter.

To qualify for an area factor increase based on frontage, a building shall have not less than 25 percent of its perimeter abut a public way, court or yard. Such court or yard shall be either on the same lot or dedicated for public use and shall have direct access, not less than 20 feet (6096 mm) wide, from a public way."

8.   Revise Section 506.3.2 to read:

"506.3.2 Minimum frontage distance.

To qualify for an area factor increase based on frontage, the public way, court or yard adjacent to the building perimeter shall have a minimum distance (W) of 20 feet (6096 mm) measured at right angles from the building face to any of the following:

1.   The closest abutting property line.

2.   The far side of a public way.

3.   The exterior face of an adjacent building on the same lot.

4.   The opposite side of a court.

Where the value of W is greater than 30 feet (9144 mm), a value of 30 feet (9144 mm) shall be used in calculating the area factor increase based on frontage, regardless of the actual width of the public way, court or yard. Where the value of W varies along the perimeter of the building, the calculation performed in accordance with Equation 5-5 shall be based on the weighted average calculated in accordance with Equation 5-4."

9.   Revise the definitions of values for Equation 5-4 by replacing "public way or open space" with "public way, court or yard" and inserting "but not greater than 30 feet (9144 mm)" at the end of the definition of Wn .

10.   Delete the exception to Section 506.3.2.

11.   Revise Equation 5-5 to read:

"If = (F/P)(W/30)(S)      (Equation 5-5)

where:

If   =   Area factor increase due to frontage.

F   =   Building perimeter that fronts on a public way or yard having a minimum width of 20 feet (6096 mm) (feet).

P   =   Perimeter of entire building (feet).

W   =   Width of public way or yard (feet) in accordance with Section 506.3.2.

S   =   Where building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, S = 2; where building is not equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2, S = 1.

(Amend Coun. J. 7-24-19, p. 3646, § 30; Amend Coun. J. 10-7-20, p. 21791, Art. II, § 7; Amend Coun. J. 6-25-21, p. 32180, Art. II, § 6)

14B-5-507 IBC Section 507.

The provisions of Section 507 of IBC are not adopted.

14B-5-508 Mixed use and occupancy.

The provisions of Section 508 of IBC are adopted by reference with the following modifications:

1.   Delete exception 1 to Section 508.1.

1.1.   Revise exception 2 to Section 508.1 by replacing "Table 415.6.2" with "the Chicago Fire Prevention Code."

2.   Revise Section 508.2.2 to read:

"508.2.2 Allowable building height.

The allowable building height and number of stories above grade plane of the building containing accessory occupancies shall be in accordance with Section 504 for the main occupancy of the building."

3.   Revise Section 508.2.3 to read:

"508.2.3 Allowable building area.

The allowable area of the building shall be based on the applicable provisions of Section 506 for the main occupancy of the building. Aggregate accessory occupancies shall not occupy more than 25 percent of the floor area of the story nor more than 10 percent of the total floor area of the main occupancy in which they are located and shall not exceed the tabular area values for nonsprinklered buildings in Table 506.2 for each such accessory occupancy.

Exception: The building official and fire code official may jointly approve accessory occupancies exceeding the 10 percent and 25 percent limits when in their opinion such accessory occupancies do not unduly increase the hazard."

4.   Revise the exceptions to Section 508.2.4 to read:

"Exceptions:

1.   Group H occupancies shall not be classified as accessory occupancies and shall be separated from all other occupancies in accordance with Section 508.4.

2.   Group I-1, R-1, R-2, R-3, R-4 and R-5 dwelling units and sleeping units shall not be classified as accessory occupancies and shall be separated from other dwelling or sleeping units and from other occupancies contiguous to them in accordance with the requirements of Section 420.

3.   Motor-vehicle-related occupancies shall not be classified as accessory occupancies and shall be separated from other occupancies in accordance with Section 406."

5.   Revise Section 508.3.2 to read:

"508.3.2 Allowable building area, height and number of stories above grade plane.

The allowable building area, building height and number of stories above grade plane of the building or portion thereof shall be based on the most restrictive allowances for the occupancy groups under consideration for the type of construction of the building in accordance with Section 503.1."

6.   Revise the exceptions to Section 508.3.3 to read:

"Exceptions:

1.   Group H occupancies shall be separated from all other occupancies in accordance with Section 508.4.

2.   Group I-1, R-1, R-2, R-3, R-4 and R-5 dwelling units and sleeping units shall be separated from other dwelling or sleeping units and from other occupancies contiguous to them in accordance with the requirements of Section 420.

3.   Group A occupancies with an aggregate occupant load of 300 or more persons shall be separated from other main occupancies by construction providing a fire-resistance rating of not less than 2 hours in buildings that are not protected throughout by an automatic sprinkler system in accordance with Section 903.3.1.1.

4.   Group A occupancies with an aggregate occupant load of less than 300 persons shall be separated from other main occupancies by construction providing a fire-resistance rating of not less than 1 hour in buildings that are not protected throughout by an automatic sprinkler system in accordance with Section 903.3.1.1.

5.   Motor-vehicle-related occupancies shall be separated from other occupancies in accordance with Section 406."

7.   Replace Table 508.4 as shown:

TABLE 508.4
REQUIRED SEPARATION OF OCCUPANCIES (HOURS) f

OCCUPANCY

A, E

I-1 a, I-3, I-4

I-2

R a

F-2, S-2 b, U

B e, M

F-1, S-1

H-1

H-2

H-3, H-4

H-5

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

S

NS

A, E

N h

N g, h

2

3

3

NP

1 h

2

1 h

2

1 h

2

1 h

2

NP

NP

4

NP

4

NP

4

NP

I-1 a, I-3, I-4

–

–

N

N

2

NP

2

NP

3

4

3

4

3

4

NP

NP

4

NP

4

NP

4

NP

I-2

–

–

–

–

N

N

2

NP

3

NP

2

NP

2

NP

NP

NP

4

NP

4

NP

4

NP

R a

–

–

–

–

–

–

N

N

1

2

1

2

1

2

NP

NP

4

NP

4

NP

4

NP

F-2, S-2 b, U

–

–

–

–

–

–

–

–

N

N

1

2

1

2

NP

NP

3

4

4

4

4

NP

B e, M

–

–

–

–

–

–

–

–

–

–

N

N

1

2

NP

NP

3

4

4

4

3

NP

F-1, S-1

–

–

–

–

–

–

–

–

–

–

–

–

N

N

NP

NP

3

4

4

4

3

NP

H-1

–

–

–

–

–

–

–

–

–

–

–

–

–

–

N

NP

NP

NP

NP

NP

NP

NP

H-2

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

N

NP

2

NP

1

NP

H-3, H-4

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

2 d

NP

1

NP

H-5

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

N

NP

 

S   =   Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

NS   =   Buildings not equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

N   =   No separation requirement.

NP   =   Not Permitted.

a.   See Section 420.

b.   The required separation from parking garages and other motor-vehicle-related occupancies shall be in accordance with Section 406.

c.   [Reserved.]

d.   Separation is not required between occupancies of the same classification.

e.   See Section 422.2 for ambulatory care facilities.

f.   Occupancy separations that serve to define fire area limits established in Chapter 9 for requiring fire protection systems shall also comply with Section 707.3.10 and Table 707.3.10 in accordance with Section 901.7.

g.   Group A occupancies with an aggregate occupant load of less than 300 persons shall be separated from other occupancies by construction providing a fire-resistance rating of not less than one 1 hour in buildings that are not protected throughout by an automatic sprinkler system in accordance with Section 903.3.1.1.

h.   Group A occupancies with an aggregate occupant load of 300 or more persons shall be separated from other occupancies by construction providing a fire-resistance rating of not less than 2 hours in buildings that are not protected throughout by an automatic sprinkler system in accordance with Section 903.3.1. 1.

8.   Revise Section 508.4.3, including the exception, to read:

"508.4.3 Allowable building height and number of stories above grade plane.

Each separated occupancy shall comply with the building height limitations and story above grade plane limitations based on the type of construction of the building in accordance with Section 503.1."

(Amend Coun. J. 2-19-20, p. 14473, Art. II, § 18; Amend Coun. J. 10-7-20, p. 21791, Art. II, § 8; Amend Coun. J. 6-25-21, p. 32180, Art. II, § 7; Amend Coun. J. 1-26-22, p. 43756, Art. II, § 5; Amend Coun. J. 1-24-24, p. 8634, Art. IV, § 1)

14B-5-509 Incidental uses.

The provisions of Section 509 of IBC are adopted by reference with the following modifications:

1.   Replace Table 509 as shown:

TABLE 509
INCIDENTAL USES

ROOM OR AREA	SEPARATION AND/OR PROTECTION
Furnace room where any piece of equipment is over 400,000 Btu per hour input	2 hours
Rooms with boilers where the largest piece of equipment is over 15 psi and 10 horsepower	2 hours
Furnace rooms and boiler rooms in buildings having an occupant load exceeding 200 persons	2 hours
Furnace rooms and boiler rooms in Group I occupancies	2 hours
Furnace rooms and boiler rooms in other than Group R-5 occupancies	1 hour
Refrigerant machinery room	1 hour
Hydrogen fuel gas rooms, not classified as Group H	1 hour in Group B, F, M, S and U occupancies; 2 hours in Group A, E, I and R occupancies.
Incinerator rooms	2 hours and provide automatic sprinkler system
Paint shops, not classified as Group H, located in occupancies other than Group F	2 hours; or 1 hour and provide automatic sprinkler system
In Group E occupancies, laboratories and vocational shops not classified as Group H	1 hour
In Group I-2 occupancies, laboratories not classified as Group H	1 hour and provide automatic sprinkler system
In ambulatory care facilities, laboratories not classified as Group H	1 hour
Laundry rooms over 100 square feet	1 hour
Group I-3 cells and Group I-2 patient rooms equipped with padded surfaces	1 hour
In Group I-2, physical plant maintenance shops	1 hour
Waste, recycling and linen collection rooms with containers that have an aggregate volume of 10 cubic feet or greater in ambulatory care facilities or Group I-2 occupancies	1 hour
Waste, recycling and linen collection rooms over 100 square feet	1 hour
Storage rooms over 100 square feet in ambulatory care facilities and Group A, E, I, R-1, R-2, R-3 or R-4 occupancies	2 hours or 1 hour and provide automatic sprinkler system
Storage rooms used for combustible material in buildings with an exhibition area	2 hours and provide automatic sprinkler system
Stationary storage battery systems having an energy capacity greater than the threshold quantity specified in the Chicago Fire Prevention Code	1 hour in Group B, F, M, S and U occupancies; 2 hours in Group A, E, I and R occupancies.
Telecommunication equipment areas over 50 square feet and not over 150 square feet	2 hours or 1 hour and provide automatic sprinkler system
Telecommunication equipment areas over 150 square feet	2 hours a
Electrical installations and transformers	See Sections 110.26 through 110.34 and Sections 450.8 through 450.48 of the Chicago Electrical Code for protection and separation requirements.

 

For SI: 1 square foot = 0.0929 m 2, 1 pound per square inch (psi) = 6.9 kPa, 1 British thermal unit (Btu) per hour = 0.293 watts, 1 horsepower = 746 watts, 1 gallon = 3.785 L, 1 cubic foot = 0.0283 m 3.

a.   Telecommunication equipment areas over 150 square feet require an automatic fire extinguishing system in accordance with section 903.2.11.7.

2.   Revise the exception to Section 509.1 to read:

"Exception: Incidental uses within and serving a single dwelling unit or sleeping unit are not required to comply with this section."

3.   Revise Section 509.3 to read:

"509.3 Area limitations.

Incidental uses shall not occupy more than 10 percent of the gross floor area of the primary occupancy in which they are located."

4.   Delete the second sentence in Section 509.4.1.

5.   Delete Section 509.4.2 and its subsections.

(Amend Coun. J. 2-19-20, p. 14473, Art. II, § 19; Amend Coun. J. 6-25-21, p. 32180, Art. II, § 8; Amend Coun. J. 12-14-22, p. 58278, Art. III, § 1)