The provisions of this chapter control the height and area of structures hereafter erected and additions to existing structures.
New and existing buildings shall be provided with approved address numbers or letters. Each character shall be not less than 4 inches (102 mm) in height and not less than 0.5 inch (12.7 mm) in width. They shall be installed on a contrasting background and be plainly visible from the street or road fronting the property. When required by the fire code official, address numbers shall be provided in additional approved locations to facilitate emergency response. Where access is by means of a private road and the building address cannot be viewed from the public way, a monument, pole or other approved sign or means shall be used to identify the structure. Address numbers shall be maintained.
| Building height limitations shown in feet above grade plane. Story limitations shown as stories above grade plane. Building area limitations shown in square feet, as determined by the definition of "Area, building," per story | ||||||||||
| GROUP | TYPE OF CONSTRUCTION | |||||||||
| TYPE I | TYPE II | TYPE III | TYPE IV | TYPE V | ||||||
| A | B | A | B | A | B | HT | A | B | ||
| HEIGHT (feet) | UL | 160 | 65 | 55 | 65 | 55 | 65 | 50 | 40 | |
| STORIES (S) AREA (A) | ||||||||||
| A-1 | S | UL | 5 | 3 | 2 | 3 | 2 | 3 | 2 | 1 |
| A | UL | UL | 15,500 | 8,500 | 14,000 | 8,500 | 15,000 | 11,500 | 5,500 | |
| A-2 | S | UL | 11 | 3 | 2 | 3 | 2 | 3 | 2 | 1 |
| A | UL | UL | 15,500 | 9,500 | 14,000 | 9,500 | 15,000 | 11,500 | 6,000 | |
| A-3 | S | UL | 11 | 3 | 2 | 3 | 2 | 3 | 2 | 1 |
| A | UL | UL | 15,500 | 9,500 | 14,000 | 9,500 | 15,000 | 11,500 | 6,000 | |
| A-4 | S | UL | 11 | 3 | 2 | 3 | 2 | 3 | 2 | 1 |
| A | UL | UL | 15,500 | 9,500 | 14,000 | 9,500 | 15,000 | 11,500 | 6,000 | |
| A-5 | S | UL | UL | UL | UL | UL | UL | UL | UL | UL |
| A | UL | UL | UL | UL | UL | UL | UL | UL | UL | |
| B | S | UL | 11 | 5 | 3 | 5 | 3 | 5 | 3 | 2 |
| A | UL | UL | 37,500 | 23,000 | 28,500 | 19,000 | 36,000 | 18,000 | 9,000 | |
| E | S | UL | 5 | 3 | 2 | 3 | 2 | 3 | 1 | 1 |
| A | UL | UL | 26,500 | 14,500 | 23,500 | 14,500 | 25,500 | 18,500 | 9,500 | |
| F-1 | S | UL | 11 | 4 | 2 | 3 | 2 | 4 | 2 | 1 |
| A | UL | UL | 25,000 | 15,500 | 19,000 | 12,000 | 33,500 | 14,000 | 8,500 | |
| F-2 | S | UL | 11 | 5 | 3 | 4 | 3 | 5 | 3 | 2 |
| A | UL | UL | 37,500 | 23,000 | 28,500 | 18,000 | 50,500 | 21,000 | 13,000 | |
| H-1 | S | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | NP |
| A | 21,000 | 16,500 | 11,000 | 7,000 | 9,500 | 7,000 | 10,500 | 7,500 | NP | |
| H-2 | S | UL | 3 | 2 | 1 | 2 | 1 | 2 | 1 | 1 |
| A | 21,000 | 16,500 | 11,000 | 7,000 | 9,500 | 7,000 | 10,500 | 7,500 | 3,000 | |
| H-3 | S | UL | 6 | 4 | 2 | 4 | 2 | 4 | 2 | 1 |
| A | UL | 60,000 | 26,500 | 14,000 | 17,500 | 13,000 | 25,500 | 10,000 | 5,000 | |
| H-4 | S | UL | 7 | 5 | 3 | 5 | 3 | 5 | 3 | 2 |
| A | UL | UL | 37,500 | 17,500 | 28,500 | 17,500 | 36,000 | 18,000 | 6,500 | |
| H-5 | S | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 2 |
| A | UL | UL | 37,500 | 23,000 | 28,500 | 19,000 | 36,000 | 18,000 | 9,000 | |
| I-1 | S | UL | 9 | 4 | 3 | 4 | 3 | 4 | 3 | 2 |
| A | UL | 55,000 | 19,000 | 10,000 | 16,500 | 10,000 | 18,000 | 10,500 | 4,500 | |
| I-2 | S | UL | 4 | 2 | 1 | 1 | NP | 1 | 1 | NP |
| A | UL | UL | 15,000 | 11,000 | 12,000 | NP | 12,000 | 9,500 | NP | |
| I-3 | S | UL | 4 | 2 | 1 | 2 | 1 | 2 | 2 | 1 |
| A | UL | UL | 15,000 | 10,000 | 10,500 | 7,500 | 12,000 | 7,500 | 5,000 | |
| I-4 | S | UL | 5 | 3 | 2 | 3 | 2 | 3 | 1 | 1 |
| A | UL | 60,500 | 26,500 | 13,000 | 23,500 | 13,000 | 25,500 | 18,500 | 9,000 | |
| GROUP | TYPE OF CONSTRUCTION | |||||||||
| TYPE I | TYPE II | TYPE III | TYPE IV | TYPE V | ||||||
| A | B | A | B | A | B | HT | A | B | ||
| HEIGHT (feet) | UL | 160 | 65 | 55 | 65 | 55 | 65 | 50 | 40 | |
| STORIES (S) AREA (A) | ||||||||||
| M | S | UL | 11 | 4 | 2 | 4 | 2 | 4 | 3 | 1 |
| A | UL | UL | 21,500 | 12,500 | 18,500 | 12,500 | 20,500 | 14,000 | 9,000 | |
| R-1 | S | UL | 11 | 4 | 4 | 4 | 4 | 4 | 3 | 2 |
| A | UL | UL | 24,000 | 16,000 | 24,000 | 16,000 | 20,500 | 12,000 | 7,000 | |
| R-2 | S | UL | 11 | 4 | 4 | 4 | 4 | 4 | 3 | 2 |
| A | UL | UL | 24,000 | 16,000 | 24,000 | 16,000 | 20,500 | 12,000 | 7,000 | |
| R-3 | S | UL | 11 | 4 | 4 | 4 | 4 | 4 | 3 | 3 |
| A | UL | UL | UL | UL | UL | UL | UL | UL | UL | |
| R-4 | S | UL | 11 | 4 | 4 | 4 | 4 | 4 | 3 | 2 |
| A | UL | UL | 24,000 | 16,000 | 24,000 | 16,000 | 20,500 | 12,000 | 7,000 | |
| S-1 | S | UL | 11 | 4 | 2 | 3 | 2 | 4 | 3 | 1 |
| A | UL | 48,000 | 26,000 | 17,500 | 26,000 | 17,500 | 25,500 | 14,000 | 9,000 | |
| S-2 | S | UL | 11 | 5 | 3 | 4 | 3 | 5 | 4 | 2 |
| A | UL | 79,000 | 39,000 | 26,000 | 39,000 | 26,000 | 38,500 | 21,000 | 13,500 | |
| U | S | UL | 5 | 4 | 2 | 3 | 2 | 4 | 2 | 1 |
| A | UL | 35,500 | 19,000 | 8,500 | 14,000 | 8,500 | 18,000 | 9,000 | 5,500 | |
| For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m 2 . |
| A = building area per story, S = stories above grade plane, UL = Unlimited, NP = Not permitted. |
| a. See the following sections for general exceptions to Table 503: |
| 1. Section 504.2, Allowable building height and story increase due to automatic sprinkler system installation. |
| 2. Section 506.2, Allowable building area increase due to street frontage. |
| 3. Section 506.3, Allowable building area increase due to automatic sprinkler system installation. |
| 4. Section 507, Unlimited area buildings. |
| b. See Chapter 4 for specific exceptions to the allowable height and areas in Chapter 5. |
Let us calculate the Height / Area requirements for you.
The building height and area shall not exceed the limits specified in Table 503 based on the type of construction as determined by Section 602 and the occupancies as determined by Section 302 except as modified hereafter. Each portion of a building separated by one or more fire walls complying with Section 706 shall be considered to be a separate building.
Buildings and structures designed to house special industrial processes that require large areas and unusual building heights to accommodate craneways or special machinery and equipment, including, among others, rolling mills; structural metal fabrication shops and foundries; or the production and distribution of electric, gas or steam power, shall be exempt from the building height and area limitations of Table 503.
Two or more buildings on the same lot shall be regulated as separate buildings or shall be considered as portions of one building if the building height of each building and the aggregate building area of the buildings are within the limitations of Table 503 as modified by Sections 504 and 506. The provisions of this code applicable to the aggregate building shall be applicable to each building.
Buildings of Type I construction permitted to be of unlimited tabular building heights and areas are not subject to the special requirements that allow unlimited area buildings in Section 507 or unlimited building height in Sections 503.1.1 and 504.3 or increased building heights and areas for other types of construction.
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The building height permitted by Table 503 shall be increased in accordance with Sections 504.2 and 504.3.
Exception: The building height of one-story aircraft hangars, aircraft paint hangars and buildings used for the manufacturing of aircraft shall not be limited if 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.
Where a building is equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the value specified in Table 503 for maximum building height is increased by 20 feet (6096 mm) and the maximum number of stories is increased by one. These increases are permitted in addition to the building area increase in accordance with Sections 506.2 and 506.3. For Group R buildings equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.2, the value specified in Table 503 for maximum building height is increased by 20 feet (6096 mm) and the maximum number of stories is increased by one, but shall not exceed 60 feet (18 288 mm) or four stories, respectively.
Exception: The use of an automatic sprinkler system to increase building heights shall not be permitted for the following conditions:
Towers, spires, steeples and other roof structures shall be constructed of materials consistent with the required type of construction of the building except where other construction is permitted by Section 1509.2.5. Such structures shall not be used for habitation or storage. The structures shall be unlimited in height if of noncombustible materials and shall not extend more than 20 feet (6096 mm) above the allowable building height if of combustible materials (see Chapter 15 for additional requirements).
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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 either the building area or number of stories as regulated by Section 503.1. The area of the mezzanine shall be included in determining 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 one-third 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.
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 two-thirds of the floor area of that room or space in which they are located.
Exceptions: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: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 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, stairs, 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 two-thirds of the room in which they are located.
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.
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The building areas limited by Table 503 shall be permitted to be increased due to frontage (If) and automatic sprinkler system protection (Is) in accordance with Equation 5-1:
| Aa = At + [At × If] + [At × Is]> | (Equation 5-1) |
| Aa | = | Allowable building area per story (square feet). |
| At | = | Tabular building area per story in accordance with Table 503 (square feet). |
| If | = | Area increase factor due to frontage as calculated in accordance with Section 506.2. |
| Is | = | Area increase factor due to sprinkler protection as calculated in accordance with Section 506.3. |
Every building shall adjoin or have access to a public way to receive a building area increase for frontage. Where a building has more than 25 percent of its perimeter on a public way or open space having a width of not less than 20 feet (6096 mm), the frontage increase shall be determined in accordance with Equation 5-2:
| If = [F/P - 0.25]W/30 | (Equation 5-2) |
| If | = | Area increase due to frontage. |
| F | = | Building perimeter that fronts on a public way or open space having 20 feet (6096 mm) open minimum width (feet). |
| P | = | Perimeter of entire building (feet). |
| W | = | Width of public way or open space (feet) in accordance with Section 506.2.1. |
To apply this section the value of W shall be not less than 20 feet (6096 mm). Where the value of W varies along the perimeter of the building, the calculation performed in accordance with Equation 5-2 shall be based on the weighted average calculated in accordance with Equation 5-3 for portions of the exterior perimeter walls where the value of W is greater than or equal to 20 feet (6096 mm). 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 weighted average, regardless of the actual width of the open space. W shall be measured perpendicular from the face of the building to the closest interior lot line. Where the building fronts on a public way, the entire width of the public way shall be used. Where two or more buildings are on the same lot, W shall be measured from the exterior face of each building to the opposing exterior face of each adjacent building, as applicable.
| Weighted average | W = (L1 × w1 + L2 × w2 + L3 × w3…)/F. | (Equation 5-3) |
| Ln | = | Length of a portion of the exterior perimeter wall. |
| wn | = | Width of open space associated with that portion of the exterior perimeter wall. |
| F | = | Building perimeter that fronts on a public way or open space having a width of 20 feet (6096 mm) or more. |
Exception: Where the building meets the requirements of Section 507, as applicable, except for compliance with the 60-foot (18 288 mm) public way or yard requirement, and the value of W is greater than 30 feet (9144 mm), the value of W divided by 30 shall be limited to a maximum of 2.