ADOPTS WITH AMENDMENTS:

International Building Code 2018 (IBC 2018)

Heads up: There are no amended sections in this chapter.

14B-5-501 The provisions of Section 501 of IBC are adopted by reference with the following modification:

Added Coun. J. 4-10-19, p. 100029.

The provisions of this chapter control the height and area of structures hereafter erected and additions to existing structures.

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

14B-5-502 The provisions of Section 502 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

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

14B-5-503 The provisions of Section 503 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

Amended Coun. J. 2-19-20, p. 14474.

503.1 General

ILLUSTRATION
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.
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.

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.

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.

14B-5-504 The provisions of Section 504 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

Amended Coun. J. 2-19-20, p. 14474.

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.

Exception: The building height of one-story aircraft hangars, aircraft paint hangars and buildings used for the manufacturing of aircraft shall not be limited where the building is provided with an automatic sprinkler system or automatic fire-extinguishing system in accordance with Chapter 9 and is entirely surrounded by public ways or yards not less in width than one and one-half times the building height.

In a building containing mixed occupancies in accordance with Section 508, no individual occupancy shall exceed the height and number of story limits specified in this section for the applicable occupancies.

504.3 Height in Feet

ILLUSTRATION

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).

TABLE 504.3

ALLOWABLE BUILDING HEIGHT IN FEET ABOVE GRADE PLANEa

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-4c M, S, U NSb 80 80 65 30 55 30 65 30 15
S UL 150 85 45 70 45 85g 45 30
H-1, H-2, H-3, H-5 NSc, d UL 80 65 30 55 NP 65 NP NP
S
I NSb 80 80 65 30 55 30 65 30 NP
S UL 150 85
R NSb 80 80 65 30 55 30 65 30e 20
S13D 40 40 40 40 40 40 40 40 35
S13R 55 55 55 45 55 45 55 45f 35
S UL 150 85 45 70 45 85g 45f 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.

  1. See Chapters 4 and 5 for specific exceptions to the allowable building height height in this chapter.
  2. See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
  3. New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
  4. The NS value is only for use in evaluation of existing buildings in accordance with the Chicago Building Rehabilitation Code.
  5. 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.
  6. 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.
  7. 120 feet for evaluation of existing building height in accordance with the Chicago Building Rehabilitation Code, for buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.

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

TABLE 504.4

ALLOWABLE NUMBER OF STORIES ABOVE GRADE PLANEa, b

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-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 NSc, d 1 1 1 1 1 1 1 1 NP
S-13 1 1 1 1 1 1 1 1 NP
H-2 NSc, d UL 3 2 1 2 1 1 NP NP
S-13 UL 3 2 1 2 1 1 NP NP
H-3 NSc, d UL 5 3 1 3 2 3 NP NP
S-13 UL 5 3 1 3 2 3 NP NP
H-4 NSc, d UL 5 4 1 3 2 4 1 NP
S-13 UL 6 5 1 4 3 5 1 NP
H-5 NSc, 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 NSd, 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 NSd, 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 UL 4 3 1 1 NP 1 1 NP
S-13 UL 5 4 1 1 NP 1 1 NP
I-2, Condition 2 NSf UL 4 3 1 1 NP 1 1 NP
S-13 UL 5 4 1 1 NP 1 1 NP
I-3 NSd, 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-13d, 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-1h NSd 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-3h 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-4h NSd 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.

  1. See Chapters 4 and 5 for specific exceptions to the allowable number of stories above grade plane in this table.
  2. See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
  3. New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
  4. The NS value is only for use in evaluation of existing buildings in accordance with the Chicago Building Rehabilitation Code.
  5. 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.
  6. 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.
  7. For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
  8. 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.

14B-5-505 The provisions of Section 505 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

Amended Coun. J. 2-19-20, p. 14474.

505.2 Mezzanines

ILLUSTRATION
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).

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:

    1. 3.1. Except for enclosed closets and bathrooms, the mezzanine shall be open to the room in which such mezzanine is located.
    2. 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.
Where a room contains both a mezzanine and an equipment platform, the aggregate area of the two raised floor levels shall be not greater than one-half of the floor area of that room or space in which they are located. The area of the mezzanine shall not exceed the area determined in accordance with Section 505.2.1.
The means of egress for mezzanines shall comply with the applicable provisions of Chapter 10.

A mezzanine shall be open and unobstructed to the room in which such mezzanine is located except for walls not more than 42 inches (1067 mm) in height, columns and posts.

Exceptions:

  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.
Equipment platforms in buildings shall not be considered as a portion of the floor below. Such equipment platforms shall not contribute to either the building area or the number of stories above grade plane as regulated by Section 503.1. The area of the equipment platform shall not be included in determining the fire area in accordance with Section 903. Equipment platforms shall not be a part of any mezzanine and such platforms and the walkways, stairways, alternating tread devices and ladders providing access to an equipment platform shall not serve as a part of the means of egress from the building.
The aggregate area of all equipment platforms within a room shall be not greater than two-thirds of the area of the room in which they are located. Where an equipment platform is located in the same room as a mezzanine, the area of the mezzanine shall be determined by Section 505.2.1 and the combined aggregate area of the equipment platforms and mezzanines shall be not greater than one-half of the room in which they are located. The area of the mezzanine shall not exceed the area determined in accordance with Section 505.2.1.
Where located in a building that is required to be protected by an automatic sprinkler system, equipment platforms shall be fully protected by sprinklers above and below the platform, where required by the standards referenced in Section 903.3.

505.3.3 Guards

ILLUSTRATION
Equipment platforms shall have guards where required by Section 1015.2.

14B-5-506 The provisions of Section 506 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

Amended Coun. J. 7-24-19, p. 3647.

Amended Coun. J. 10-7-20, p. 21791. 

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.
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.
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).

The allowable area of a building shall be determined in accordance with the applicable provisions of Sections 506.2.1 through 506.2.4 and Section 506.3.

TABLE 506.2
ALLOWABLE AREA FACTOR (At = NS, S1, S13R, S13D or SM, as applicable) IN SQUARE FEETa, 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 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 NSc, 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 NSc, 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 NSc, 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 NSc, 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 NSc, 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 NSd, 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 NSd, 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 NSd, 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 NSd, 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 165,500 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-1h NSd 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-3h 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-4h NSd 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 4,000i
S1 UL UL UL UL 84,000 40,000 108,000 24,000 16,000i
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 m2.

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.

  1. See Chapter 4 for specific exceptions to the allowable area factor in this table.
  2. See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
  3. New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
  4. The NS value is only for use in evaluation of existing buildings in accordance with the Chicago Building Rehabilitation Code.
  5. 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.
  6. 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.
  7. New Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
  8. 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.
  9. Type VB construction is not allowed for motor-vehicle-related occupancies other than private garages.

The allowable area of a single-occupancy building with no more than one story above grade plane shall be determined in accordance with Equation 5-1:


(Equation 5-1)

where:

Aa = Allowable area (square feet).

At = Tabular allowable area factor (NS, S1, S13R or S13D value, as applicable) in accordance with Table 506.2.

NS = Tabular allowable area factor in accordance with Table 506.2 for nonsprinklered building (regardless of whether the building is sprinklered).

If = Area factor increase due to frontage (percent) as calculated in accordance with Section 506.3.

The allowable area of a mixed-occupancy building with no more than one story above grade plane shall be determined in accordance with the applicable provisions of Section 508.1 based on Equation 5-1 for each applicable occupancy.
For a building containing Group H-2 or H-3 occupancies, the allowable area shall be determined in accordance with Section 508.4.2, with the sprinkler system increase applicable only to the portions of the building not classified as Group H-2 or H-3.

The allowable area of a single-occupancy building with more than one story above grade plane shall be determined in accordance with Equation 5-2:


(Equation 5-2)

where:

Aa = Allowable area (square feet).

At = Tabular allowable area factor (NS, S13R, S13D or SM value, as applicable) in accordance with Table 506.2.

NS = Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered building (regardless of whether the building is sprinklered).

If = Area factor increase due to frontage (percent) as calculated in accordance with Section 506.3.

Sa = Actual number of building stories above grade plane, not to exceed three.

No individual story shall exceed the allowable area (Aa) as determined by Equation 5-2 using the value of Sa = 1.

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.


(Equation 5-3)

where:

Aa = Allowable area (square feet).

At = Tabular allowable area factor (NS, S13R, S13D or SM value, as applicable) in accordance with Table 506.2.

NS = Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered building (regardless of whether the building is sprinklered).

If = Area factor increase due to frontage (percent) as calculated in accordance with Section 506.3.

For a building containing Group H-2 or H-3 occupancies, the allowable area shall be determined in accordance with Section 508.4.2, with the sprinkler system increase applicable only to the portions of the building not classified as Group H-2 or H-3.
Every building shall adjoin or have access to a public way to receive an area factor increase based on frontage. Area factor increase shall be determined in accordance with Sections 506.3.1 through 506.3.3.
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 or yard. Such 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.

To qualify for an area factor increase based on frontage, the public way 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.

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 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.


(Equation 5-4)

where:

W (Width: weighted average) = Calculated width of public way or yard (feet).

Ln = Length of a portion of the exterior perimeter wall.

wn=Width (≥ 20 feet) of a public way or yard associated with that portion of the exterior perimeter wall.

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

The area factor increase based on frontage shall be determined in accordance with Equation 5-5:


(Equation 5-5)

where:

If = Area factor increase due to frontage.

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

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.

14B-5-507 The provisions of Section 507 of IBC are not adopted.

Added Coun. J. 4-10-19, p. 100029.

14B-5-508 The provisions of Section 508 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

Amended Coun. J. 2-19-20, p. 14474.

Amended Coun. J. 10-7-20, p. 21791.

Each portion of a building shall be individually classified in accordance with Section 302.1. Where a building contains more than one occupancy group, the building or portion thereof shall comply with the applicable provisions of Section 508.2, 508.3 or 508.4, or a combination of these sections.

Exceptions:

  1. [Reserved]
  2. Where required by  the Chicago Fire Prevention Code, areas of Group H-1, H-2 and H-3 occupancies shall be located in a detached building or structure.
  3. Uses within live/work units, complying with Section 419, are not considered separate occupancies.
Accessory occupancies are those occupancies that are ancillary to the main occupancy of the building or portion thereof. Accessory occupancies shall comply with the provisions of Sections 508.2.1 through 508.2.4.
Accessory occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space.
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.

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 5 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 5 percent and 25 percent limits when in their opinion such accessory occupancies do not unduly increase the hazard.

No separation is required between accessory occupancies and the main occupancy.

Exceptions:

  1. Group H occupancies shall not be classified as accessory occupancies and 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.
Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.
Nonseparated occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space. In addition, the most restrictive provisions of Chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area.
Where nonseparated occupancies occur in a high-rise building, the most restrictive requirements of Section 403 that apply to the nonseparated occupancies shall apply throughout the high-rise building.
Where one of the nonseparated occupancies is Group I-2, Condition 2, the most restrictive requirements of Sections 407, 509 and 712 shall apply throughout the fire area containing the Group I-2 occupancy. The most restrictive requirements of Chapter 10 shall apply to the path of egress from the Group I-2, Condition 2 occupancy up to and including the exit discharge.
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.

No separation is required between nonseparated occupancies.

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 all other main occupancies by construction providing a fire-resistance rating of not less than 2 hours.
  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.

Buildings or portions of buildings that comply with the provisions of this section shall be considered as separated occupancies.

TABLE 508.4

REQUIRED SEPARATION OF OCCUPANCIES (HOURS)f

OCCUPANCY A, E I-1a, I-3, I-4 I-2 Ra F-2, S-2b, U Be, F-1, M, 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
A, E Nh Ng, h 2 3 3 NP 1h 2 1h 2 1h 2 NP NP 4 NP 4 NP 4 NP
I-1a, I-3, I-4 N N 2 NP 2 NP 3 4 3 4 NP NP 4 NP 4 NP 4 NP
I-2 N N 2 NP 3 NP 2 NP NP NP 4 NP 4 NP 4 NP
Ra N N 1 2 1 2 NP NP 4 NP 4 NP 4 NP
F-2, S-2b, U N N 1 2 NP NP 3 4 4 4 4 NP
Be, F-1, M, 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 2d 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.

  1. See Section 420.
  2. The required separation from parking garages and other motor-vehicle-related occupancies shall be in accordance with Section 406.
  3. [Reserved]
  4. Separation is not required between occupancies of the same classification.
  5. See Section 422.2 for ambulatory care facilities.
  6. 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.
  7. 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.
  8. 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.
Separated occupancies shall be individually classified in accordance with Section 302.1. Each separated space shall comply with this code based on the occupancy classification of that portion of the building. The most restrictive provisions of Chapter 9 that apply to the separate occupancies shall apply to the total nonfire-barrier-separated occupancy areas. Occupancy separations that serve to define fire area limits established in Chapter 9 for requiring a fire protection system shall also comply with Section 901.7.
In each story, the building area shall be such that the sum of the ratios of the actual building area of each separated occupancy divided by the allowable building area of each separated occupancy shall not exceed 1.
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.
Individual occupancies shall be separated from adjacent occupancies in accordance with Table 508.4.
Required separations shall be fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both, so as to completely separate adjacent occupancies.

14B-5-509 The provisions of Section 509 of IBC are adopted by reference with the following modifications:

Added Coun. J. 4-10-19, p. 100029.

Amended Coun. J. 2-19-20, p. 14474.

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 2 hoursa
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 m2, 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 m3.

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

Incidental uses located within single occupancy or mixed occupancy buildings shall comply with the provisions of this section. Incidental uses are ancillary functions associated with a given occupancy that generally pose a greater level of risk to that occupancy and are limited to those uses listed in Table 509.

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

Incidental uses shall not be individually classified in accordance with Section 302.1. Incidental uses shall be included in the building occupancies within which they are located.
Incidental uses shall not occupy more than 10 percent of the gross floor area of the primary occupancy in which they are located.
The incidental uses listed in Table 509 shall be separated from the remainder of the building or equipped with an automatic sprinkler system, or both, in accordance with the provisions of that table.
Where Table 509 specifies a fire-resistance-rated separation, the incidental uses shall be separated from the remainder of the building by a fire barrier constructed in accordance with Section 707 or a horizontal assembly constructed in accordance with Section 711, or both.

14B-5-510 The provisions of Section 510 of IBC are not adopted.

Added Coun. J. 4-10-19, p. 100029.

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