CBC · California Building Code

How to classify occupiable roofs and multipurpose spaces

Q: Can I put any type of occupancy on a rooftop if I only want a small outdoor seating area?

Not automatically. §503.1.4 requires that the roof occupancy be an occupancy permitted above the story immediately below per Table 504.4, unless you meet the sprinkler/notification exception. If the occupancy is permitted (or you qualify under the exception), then apply all occupancy‑specific requirements (egress, fire protection, etc.).

Q: Do occupiable roofs count toward building height or area limits?

Generally no — occupiable roof areas are not counted in building area under Section 506 and are not counted as an additional story for height/number‑of‑stories calculations under Section 504, subject to rooftop enclosures and penthouse rules. See §503.1.4.

Q: How many exits does a rooftop event space need?

Calculate exits using the occupant load for the roof alone and then apply Table 1006.3.3: 2 exits for 1–500 occupants; 3 for 501–1,000; 4 for more than 1,000. Single‑exit allowances are narrow and depend on Tables 1006.3.4(1)/(2) by occupancy.

Q: Can I reduce the structural live load for a rooftop garden?

Possibly. The code provides roof live‑load reduction rules specifically for occupiable roofs (see §1607.14.2). Those reductions are permitted only when the Chapter 16 criteria and formulas are correctly applied. Consult the structural provisions in Chapter 16.

Q: What if I want high screens or a small enclosed room on the roof?

Enclosing elements over occupiable roof areas are generally limited to 48 inches in height above the roof surface (§503.1.4.1). Penthouses constructed per §1511 or roofs located more than 75 feet above fire‑department access are exceptions.

If you want to use a roof for people (landscape deck, rooftop bar, assembly), CBC §302.1 says you must assign the roof to the occupancy it most resembles and meet that occupancy’s rules. §503.1.4 tells when a rooftop use is permitted above the story below and the sprinkler/notification exception that can broaden allowed uses; egress, enclosure height, and roof live‑load provisions are then applied specifically for the occupiable roof.

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Last reviewed: July 5, 2026

What the code requires — in plain English

Occupiable roofs (roofs intended for people — e.g., landscaped roofs, assembly decks, rooftop bars, marquees) must be classified by occupancy in the same way any other space is: assign the roof to the occupancy group that it most nearly resembles based on fire safety and relative hazard, and then treat it under the provisions that apply to that occupancy. The governing instruction is §302.1, which also directs you to the special occupiable‑roof rules in §503.1.4.

Requirements in detail

1) Occupancy classification: same rule as other spaces

An occupiable roof is not a special standalone category — you must designate its occupancy group by matching the roof’s intended use to the occupancy it most closely resembles (fire hazard and relative risk). See §302.1.
After you assign the occupancy, the roof must comply with the code requirements for that occupancy (means of egress, fire protection, allowable location, etc.), and in some cases additional roof‑specific rules in Chapter 5 apply (see §503.1.4).

2) Where occupiable roofs are permitted and how they count for height/area

A roof (or portion of a roof) may be used as an occupiable roof only when the roof occupancy is one that is permitted for the story immediately below the roof per Table 504.4, unless a sprinkler/notification exception applies. See §503.1.4.
Occupiable roof areas are not included in the building area calculations under Section 506. A permitted occupiable roof is generally not counted as an additional story or added into the building height limits under Section 504 — subject to the penthouse/enclosed rooftop structure rules in §1511. See §503.1.4.

3) Enclosure height over occupiable roofs

Elements or structures that enclose occupiable roof areas (guards, low parapets, small enclosure walls) are limited in height: such enclosing elements shall not extend more than 48 inches above the occupiable roof surface, except for penthouses built under §1511 or where the roof deck is more than 75 feet above the lowest level of fire department vehicle access. See §503.1.4.1.

4) Means of egress for occupiable roofs

Egress rules treat occupiable roofs like stories: each occupiable roof must have the required number of separate and distinct exits or access to exits based on the occupant load located on that roof alone. Use the egress tables and provisions for “story or occupiable roof.” See §1006.3 and §1006.3.1.
Minimum exits by occupant load: Table 1006.3.3 establishes the minimum number of exits per story or occupiable roof (2 exits for 1–500 occupants; 3 exits for 501–1,000; 4 for more than 1,000). See §1006.3.3 and Table 1006.3.3.
Single‑exit conditions: a single exit may be permitted from a story or occupiable roof only if the occupant load, exit access travel distance, and other criteria in Table 1006.3.4(1) or Table 1006.3.4(2) are met (these tables list limits by occupancy and story). See §1006.3.4 and Tables 1006.3.4(1)/(2).

5) Structural live loads for occupiable roofs

Roof areas that are occupiable (vegetative roofs, landscaped roofs, roofs used for assembly or similar purposes, marquees) are permitted to have roof live loads reduced in accordance with the roof live‑load reduction provisions in Chapter 16 (see 1607.13/1607.14.2). That means the designer may apply the roof live‑load reduction rules specifically allowed for occupiable roofs when sizing structural members, provided the conditions in Chapter 16 are followed. See §1607.14.2.

Decision-relevant dimensions and quick code references

Decision dimension / value	What to check in the CBC	Code reference
How to assign occupancy to roof	Match roof use to the occupancy group that it most nearly resembles (fire hazard) — then apply that occupancy’s requirements	§302.1
Whether the roof occupancy is permitted	Roof occupancy must be allowed for the story immediately below per Table 504.4, unless sprinkler/notification exception applies	§503.1.4
Does occupiable roof add to building area or height?	Occupiable roof area is not included in building area; occupiable roof generally not counted as a story or height (see penthouse rules)	§503.1.4 and §1511
Guard/enclosure height over roof	Enclosing elements shall not extend more than 48 in. above roof surface (exceptions noted)	§503.1.4.1
Minimum number of exits	Based on occupant load for that roof alone; use Table 1006.3.3 (2 exits for 1–500 occupants, etc.)	§1006.3.3 / Table 1006.3.3
Single-exit allowable?	Allowed only if occupant count and travel distance meet Tables 1006.3.4(1)/(2) for the occupancy/story.	§1006.3.4 and Tables 1006.3.4(1)/(2)
Structural live-load reductions	Occupiable roofs may use the reduced roof live-load provisions in Chapter 16 (1607.14.2) when applicable	§1607.14.2

Exceptions & special cases

Sprinkler/notification exception for rooftop occupancies: If the building is equipped throughout with an automatic sprinkler system (per §903.3.1.1 or .1.2) and occupant notification (and, where required, emergency voice/alarm communication) is provided in the occupiable roof area, the roof occupancy is not limited to the occupancies allowed on the story immediately below. In other words, sprinkler/notification can allow other occupancy types on the roof that Table 504.4 would otherwise limit. See §503.1.4 Exceptions.
Enclosure exceptions: penthouses built per §1511, or enclosing elements where the roof deck is more than 75 feet above the lowest level of fire department vehicle access, are allowed to exceed the 48‑inch enclosure limit in §503.1.4.1.
Assembly on open parking roofs: Assembly occupancies are permitted on roofs of open parking spaces of Type I or Type II construction under the exception noted in §503.1.4 (see code for limits).

If you need to know which specific occupancies Table 504.4 allows above a particular story, that Table’s content was not included in the files provided here; check Table 504.4 in the CBC for the precise list.

Common mistakes

Treating “occupiable roof” as automatically Group A (assembly). The roof’s assigned occupancy must match the intended use and the hazard; rooftop lounges, landscaped roofs, and rooftop mechanical/plaza areas can fall into different groups depending on use — follow §302.1.
Forgetting that the occupiable roof’s egress is calculated based on the roof’s occupant load alone. Designers sometimes combine roof load with the story below when sizing exits — do not do that; use §1006.3 and §1006.3.1.
Assuming occupiable roofs always add to building height/area. In fact occupiable roofs are not included in building area (Section 506) and, when authorized, are not counted as an extra story (Section 504/§503.1.4) — but rooftop enclosures and penthouses still must comply with other rules (§1511).
Overlooking occupant-notification and sprinkler requirements that can change what occupancies are permitted on a roof (the §503.1.4 exception).
Missing the roof‑load structural provisions: occupiable roofs may qualify for live‑load reduction per Chapter 16, but only when those reduction rules are properly applied — consult §1607.14.2.

Worked example — rooftop bar on a third‑story roof (concrete scenario)

Scenario: A developer proposes a 2,000 ft² rooftop bar on the roof above the third story of a building. The area is intended for assembly seating for patrons and will accommodate a calculated occupant load of 120 people.

Step 1 — occupancy classification: The rooftop use (bar/restaurant seating) resembles an Assembly occupancy (Group A). Per §302.1, classify the occupiable roof according to the occupancy it most nearly resembles (Assembly).

Step 2 — is that occupancy permitted at roof level?: Check §503.1.4 — the roof occupancy must be allowed for the story immediately below per Table 504.4 unless the building is fully sprinklered and the roof area has occupant notification/EVACS. If the building is not sprinklered throughout, and Table 504.4 does not allow an assembly on that story, the rooftop bar is not permitted as proposed. If the building is sprinklered and the notification systems are provided on the roof, the exception in §503.1.4 allows assembly on the roof.

Step 3 — egress: Determine minimum number of exits for the roof by using the occupant load for that roof alone.

Table 1006.3.3 requires a minimum of 2 exits for any story or occupiable roof with 1–500 occupants. With 120 occupants, the roof requires at least 2 separate exits (you cannot rely on the occupant load of the story below). See §1006.3.3 / Table 1006.3.3.
Check single‑exit exceptions: Table 1006.3.4(2) limits single‑exit conditions for Assembly occupancies; for many A occupancies the single‑exit occupant threshold is far below 120 (e.g., Table 1006.3.4(2) shows 49 occupants for a first‑story occupiable roof in many occupancy types). Therefore, a single exit is not allowed here. See §1006.3.4 and Table 1006.3.4(2).

Step 4 — enclosure and height impacts:

Any enclosure over the roof seating area (screens, low walls) must not extend more than 48 in. above the roof surface unless an exception applies. See §503.1.4.1.

Step 5 — structure:

Since this is an occupiable roof used for assembly, check structural live‑load rules: occupiable roofs may qualify for the roof live‑load reduction provisions in Chapter 16 (see §1607.14.2). Apply the Chapter 16 criteria and reduction provisions before reducing roof live loads for members.

In short: for 120 occupants you will need at least two approved exits sized and routed per the means‑of‑egress chapter; confirm allowed occupancy above the story below (or provide buildingwide sprinklers and roof notification to use the exception); limit enclosure heights to 48 in. unless exempt; and follow Chapter 16 rules for any roof live‑load reductions.

Related provisions (read these sections next)

§302.1 — Occupancy classification and the rule for occupiable roofs.
§503.1.4 — Occupiable roofs (permissions, how they count for area/height).
§503.1.4.1 — Enclosures over occupiable roofs (48‑inch limit and exceptions).
§1511 — Penthouses and rooftop structures (applies to penthouses/enclosed rooftop structures).
§1006.3 / §1006.3.1 / §1006.3.3 / §1006.3.4 — Means of egress for stories and occupiable roofs, occupant‑load treatment, and single‑exit rules (includes Tables 1006.3.3 and 1006.3.4(1)/(2)).
§1607.14.2 — Roof live‑load reduction rules applicable to occupiable roofs (Chapter 16 structural provisions).

Code references

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

CBC § 301.1 High relevance — show source text
ICC code development note: Code change proposals to sections preceded by the designation [F] will be considered by the IFC code development committee meeting during the 2024 (Group A) Code Development Cycle. All other code change proposals will be considered by a code development committee meeting during the 2025 (Group B) Code Development Cycle.

SECTION 301—SCOPE

301.1 General. The provisions of this chapter shall control the classification of all buildings and structures as to occupancy and use. Different classifications of occupancy and use represent varying levels of hazard and risk to building occupants and adjacent properties.

SECTION 302—OCCUPANCY CLASSIFICATION AND USE DESIGNATION

302.1 Occupancy classification. Occupancy classification is the formal designation of the primary purpose of the building, structure or portion thereof. Structures shall be classified into one or more of the occupancy groups specified in this section based on the nature of the hazards and risks to building occupants generally associated with the intended purpose of the building or structure. An area, room or space that is intended to be occupied at different times for different purposes shall comply with all applicable requirements associated with such potential multipurpose. Structures containing multiple occupancy groups shall comply with Section 508. Where a structure is proposed for a purpose that is not specified in this section, such structure shall be classified in the occupancy it most nearly resembles based on the fire safety and relative hazard. Occupiable roofs shall be classified in the group that the occupancy most nearly resembles, according to the fire safety and relative hazard, and shall comply with Section 503.1.4.
1. Assembly (see Section 303): Groups A-1, A-2, A-3, A-4 and A-5.
2. Business (see Section 304): Group B. 3. [SFM] Organized Camps (see Section 450): Group C. 4. Educational (see Section 305): Group E. 5. Factory and Industrial (see Section 306): Groups F-1 and F-2. 6. High Hazard (see Section 307): Groups H-1, H-2, H-3, H-4 and H-5. 7. Institutional (see Section 308): Groups I-2, I-3 and I-4. 8. [SFM] Laboratory (see Section 202): Group B, unless classified as Group L (see Section 453) or Group H (see Section 307). 9. [SFM] Laboratory Suites (see Section 453): Group L. 10. Mercantile (see Section 309): Group M. 11 . Residential (see Section 310): Groups R-1, R-2, R-2.1, R-3, R-3.1 and R-4. 12 . Storage (see Section 311): Groups S-1 and S-2. 13 . Utility and Miscellaneous (see Section 312): Group U. 14. [SFM] Existing buildings housing existing protective social care homes or facilities established prior to 1972 (see California Fire Code Chapter 11 and California Existing Building Code).
302.1.1 Reserved

302.1.2 Reserved

302.1.3 Pharmacies; veterinary facilities; barbering, cosmetology or electrolysis establishments; and acupuncture offices. See Chapter 12.
CBC § 310.2 High relevance — show source text
1|||X|||||||||||||||||||||| |310.2|||X|X||||||||||||||||||||| |310.3|||X|X||||||||||||||||||||| |310.3.1|||X|||||||||||||||||||||| |310.3.2|||X|||||||||||||||||||||| |310.4|||X|X||||||||||||||||||||| |310.4.1|||X|||||||||||||||||||||| |310.4.2|||X|X|X|||||||||||||||||||| |310.5|||X|||||||||||||||||||||| |310.6|||X|||||||||||||||||||||| |313|||X|||||||||||||||||||||| |314|||X||||||||||||||||||||||

The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

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OCCUPANCY CLASSIFICATION AND USE

User notes:

About this chapter: Chapter 3 provides the criteria by which buildings and structures are classified into use groups and occupancies. Through the balance of the code, occupancy classification is fundamental in the setting of features of construction; occupant safety requirements, especially building limitations; means of egress; fire protection systems; and interior finishes.

ICC code development note: Code change proposals to sections preceded by the designation [F] will be considered by the IFC code development committee meeting during the 2024 (Group A) Code Development Cycle. All other code change proposals will be considered by a code development committee meeting during the 2025 (Group B) Code Development Cycle.

SECTION 301—SCOPE

301.1 General. The provisions of this chapter shall control the classification of all buildings and structures as to occupancy and use. Different classifications of occupancy and use represent varying levels of hazard and risk to building occupants and adjacent properties.

SECTION 302—OCCUPANCY CLASSIFICATION AND USE DESIGNATION

302.1 Occupancy classification. Occupancy classification is the formal designation of the primary purpose of the building, structure or portion thereof. Structures shall be classified into one or more of the occupancy groups specified in this section based on the nature of the hazards and risks to building occupants generally associated with the intended purpose of the building or structure. An area, room or space that is intended to be occupied at different times for different purposes shall comply with all applicable requirements associated with such potential multipurpose. Structures containing multiple occupancy groups shall comply with Section 508. Where a structure is proposed for a purpose that is not specified in this section, such structure shall be classified in the occupancy it most nearly resembles based on the fire safety and relative hazard. Occupiable roofs shall be classified in the group that the occupancy most nearly resembles, according to the fire safety and relative hazard, and shall comply with Section 503.1.4.
1. Assembly (see Section 303): Groups A-1, A-2, A-3, A-4 and A-5.
2. Business (see Section 304): Group B.
CBC § 0.58 High relevance — show source text
where: 12 ≤ L r ≤ 20

For SI: L r = L o R 1 R 2

where: 0.58 ≤ L r ≤ 0.96 L o = Unreduced roof live load per square foot (m [2] ) of horizontal projection supported by the member (see Table 1607.1). L r = Reduced roof live load per square foot (m [2] ) of horizontal projection supported by the member.

The reduction factors R 1 and R 2 shall be determined as follows: Equation 16-11 R 1 = 1 for A t ≤ 200 square feet (18.58 m [2] )

Equation 16-12 R 1 = 1.2 - 0.001 A t for 200 square feet < A t < 600 square feet Equation 16-13 R 1 = 0.6 for A t ≥ 600 square feet (55.74 m [2] )

where:

A t = Tributary area (span length multiplied by effective width) in square feet (m [2] ) supported by the member, and

Equation 16-14 R 2 = 1 for F ≤ 4

Equation 16-15 R 2 = 1.2 - 0.05 F for 4 < F < 12

Equation 16-16 R 2 = 0.6 for F ≥ 12

where:

F = For a sloped roof, the number of inches of rise per foot (for SI: F = 0.12 × slope, with slope expressed as a percentage), or for an arch or dome, the rise-to-span ratio multiplied by 32.

1607.14.2 Occupiable roofs. Areas of roofs that are occupiable, such as vegetative roofs, landscaped roofs or for assembly or other similar purposes, and marquees are permitted to have their uniformly distributed live loads reduced in accordance with Section 1607.13.

1607.14.3 Photovoltaic panel systems. Roof structures that provide support for photovoltaic panel systems shall be designed in accordance with Sections 1607.14.3.1 through 1607.14.3.5, as applicable.

1607.14.3.1 Roof live load. Roof structures that support photovoltaic panel systems shall be designed to resist each of the following conditions:
1. Applicable uniform and concentrated roof loads with the photovoltaic panel system dead loads. Exception: Roof live loads need not be applied to the area covered by photovoltaic panels where the clear space between the panels and the roof surface is 24 inches (610 mm) or less.
2. Applicable uniform and concentrated roof loads without the photovoltaic panel system present.
1607.14.3.2 Photovoltaic panels or modules. The structure of a roof that supports solar photovoltaic panels or modules shall be designed to accommodate the full solar photovoltaic panels or modules and ballast dead load, including concentrated

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STRUCTURAL DESIGN
CBC § 1006.3.3 High relevance — show source text
Where basements are used for day-care purposes, one of the two required exits shall provide access directly to the exterior without entering the first story. The second exit from the basement may either pass through the story above or exit directly to the exterior.

Rooms used for day-care purposes shall not be located above the first story.

Exception: Buildings equipped with an automatic sprinkler system throughout and which have at least one of the required exits providing access directly to the exterior. NFPA 13R may be used in large family day-care homes. The sprinkler omissions of NFPA 13R shall not apply unless approved by the enforcing agency.

Exit doors, including manually operated horizontal sliding doors, shall be openable from the inside without use of a key or any special knowledge or effort.

Tables 1006.3.3(1) and 1006.3.3(2) are not applicable to this occupancy classification.

1006.2.2.8 Group I-4 means of egress. Group I-4 facilities, rooms or spaces where care is provided for more than 10 children that are 36 months of age or less shall have access to not less than two exits or exit access doorways.

1006.3 Egress from stories or occupiable roofs. All spaces located on a story or occupiable roof shall have access to the required number of separate and distinct exits or access to exits based on the aggregate occupant load served in accordance with this section.

1006.3.1 Occupant load. Where stairways serve more than one story, or more than one story and an occupiable roof, only the occupant load of each story or occupiable roof, considered individually, shall be used when calculating the required number of exits or access to exits serving that story.

1006.3.2 Path of egress travel. The path of egress travel to an exit shall not pass through more than one adjacent story.

Exception: The path of egress travel to an exit shall be permitted to pass through more than one adjacent story in any of the following:
1. In Group R-1, R-2 or R-3 occupancies, exit access stairways and ramps connecting four stories or less serving and contained within an individual dwelling unit, sleeping unit or live/work unit.
2. Exit access stairways serving and contained within a Group R-3 congregate residence or a Group R-4 facility.
3. Exit access stairways and ramps within an atrium complying with Section 404.
4. Exit access stairways and ramps in open parking garages that serve only the parking garage.
5. Exit access stairways and ramps serving smoke-protected assembly seating and open-air assembly seating complying with the exit access travel distance requirements of Section 1030.7.
6. Exit access stairways and ramps between the balcony, gallery or press box and the main assembly floor in occupancies such as theaters, places of religious worship, auditoriums and sports facilities.
7. Exterior exit access stairways and ramps between occupiable roofs.
1006.3.3 Egress based on occupant load. Each story and occupiable roof shall have the minimum number of separate and distinct exits, or access to exits, as specified in Table 1006.3.3. A single exit or access to a single exit shall be permitted in accor

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MEANS OF EGRESS

CBC § 1006.3.4. High relevance — show source text

dance with Section 1006.3.4. The required number of exits, or exit access stairways or ramps providing access to exits, from any story or occupiable roof shall be maintained until arrival at the exit discharge or a public way.

TABLE 1006.3.3—MINIMUM NUMBER OF EXITS OR ACCESS TO EXITS PER STORY OR OCCUPIABLE ROOFS	Col2
OCCUPANT LOAD PER STORY OR OCCUPIABLE ROOF	MINIMUM NUMBER OF EXITS OR ACCESS TO EXITS PER STORY OR OCCUPIABLE ROOF
1-500	2
501-1,000	3
More than 1,000	4

1006.3.4 Single exits. A single exit or access to a single exit shall be permitted from any story or occupiable roof where one of the following conditions exists:

The occupant load, number of dwelling units and exit access travel distance do not exceed the values in Table 1006.3.4(1) or 1006.3.4(2).
Rooms, areas and spaces complying with Section 1006.2.1 with exits that discharge directly to the exterior at the level of exit discharge, are permitted to have one exit or access to a single exit.
Parking garages where vehicles are mechanically parked shall be permitted to have one exit or access to a single exit.
Group R-3 and R-4 occupancies shall be permitted to have one exit or access to a single exit.
Individual single-story or multistory dwelling units shall be permitted to have a single exit or access to a single exit from the dwelling unit provided that both of the following criteria are met: 5.1. The dwelling unit complies with Section 1006.2.1 as a space with one means of egress. 5.2. Either the exit from the dwelling unit discharges directly to the exterior at the level of exit discharge, or the exit access outside the dwelling unit’s entrance door provides access to not less than two approved independent exits.

TABLE 1006.3.4(1)—STORIES AND OCCUPIABLE ROOFS WITH ONE EXIT OR ACCESS TO ONE EXIT FOR R-2 AND R-3 OCCUPANCIES	Col2	Col3	Col4
STORY	OCCUPANCY	MAXIMUM NUMBER OF DWELLING UNITS	MAXIMUM EXIT ACCESS TRAVEL DISTANCE
Basement, first, second or third story above grade plane and occupi- able roofs over the first or second story above grade plane	R-2a, b, c R-3a	4 dwelling units NA	125 feet NA
Fourth story above grade plane and higher	R-3a	NA	125 feet
For SI: 1 foot = 304.8 mm. NP = Not Permitted. NA = Not Applicable. a. Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency escape and rescue openings in accordance with Section 1031. b. This table is used for Group R-2 occupancies consisting of dwelling units. For Group R-2 occupancies consisting of sleeping units, use Table 1006.3.4(2). c.

CBC § 501A.3.3.3 High relevance — show source text
501A.3.3.3 For NPC 3 and NPC 4 or NPC 4D in SPC 2, SPC 3, SPC 4 or SPC-4D buildings, the adequacy and design of nonstructural component or equipment supports and attachments may extend only to the connection of the component or equipment to the support when the total reaction at the point of support (including the application of F p ) is less than or equal to the following limits: 1. 250 pounds for components or equipment attached to light frame walls. For the purposes of this requirement, the sum of the absolute value of all reactions due to component loads on a single stud shall not exceed 250 pounds. 2. 1,000 pounds for components or equipment attached to roofs or walls of reinforced concrete or masonry construction. 3. 2,000 pounds for components or equipment attached to floors or slabs-on-grade.

Exception: If the anchorage or bracing is configured in a manner that results in significant torsion on a supporting structural element, the effects of the nonstructural reaction force on the structural element shall be considered in the anchorage design.

501 A . 4 Health care facilities. In Group I-2 facilities, ambulatory care facilities and outpatient clinics, any altered or added portion of an existing electrical or medical gas systems shall be required to meet installation and equipment requirements in NFPA 99.

SECTION 502 A —ADDITIONS

502 A .1 General. Additions to any building or structure shall comply with the requirements of the California Building Code for new construction. Alterations to the existing building or structure shall be made to ensure that the existing building or structure together with the addition are not less complying with the provisions of the California Building Code than the existing building or structure was prior to the addition. An existing building together with its additions shall comply with the height and area provisions of Chapter 5 of the California Building Code . Where a new occupiable roof is added to a building or structure, the occupiable roof shall comply with the provisions of the California Building Code.

Exception: In-filling of floor openings and nonoccupiable appendages such as elevator and exit stairway shafts shall be permitted beyond that permitted by the California Building Code.

502 A .1.1 Risk category assignment. Where the addition and the existing building have different occupancies, the risk category of each existing and added occupancy shall be determined in accordance with Section 1604 A .5.1 of the California Building Code . Where application of that section results in a higher risk category for the existing building compared with the risk category for the existing building before the addition, such a change shall be considered a change of occupancy and shall comply with Section 506 A of this code. Where application of that section results in a higher risk category for the addition compared with the risk category for the addition by itself, the addition and any systems in the existing building required to serve the addition shall comply with the requirements of the California Building Code for new construction for the higher risk category.

502 A .1.2 Creation or extension of nonconformity. An addition shall not create or extend any nonconformity in the existing building to which the addition is being made with regard to accessibility, structural strength, supports and attachments for nonstructural components, fire safety, means of egress or the capacity of mechanical, plumbing or electrical systems.

CBC § 1006.3.4 Medium relevance — show source text

For Group R-2 occupancies with occupiable roofs that are
not accessed through and serving individual units, use Table 1006.3.4(2).|For SI: 1 foot = 304.8 mm.
NP = Not Permitted.
NA = Not Applicable.
a. Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency
escape and rescue openings in accordance with Section 1031.
b. This table is used for Group R-2 occupancies consisting of dwelling units. For Group R-2 occupancies consisting of sleeping units, use Table 1006.3.4(2).
c. This table is for occupiable roofs accessed through and serving individual dwelling units in Group R-2 occupancies. For Group R-2 occupancies with occupiable roofs that are
not accessed through and serving individual units, use Table 1006.3.4(2).|

TABLE 1006.3.4(2)—STORIES AND OCCUPIABLE ROOFS WITH ONE EXIT OR ACCESS TO ONE EXIT FOR OTHER OCCUPANCIES	Col2	Col3	Col4
STORY AND OCCUPIABLE ROOF	OCCUPANCYe	MAXIMUM OCCUPANT LOAD PER STORY AND OCCUPIABLE ROOF	MAXIMUM EXIT ACCESS TRAVEL DISTANCE (feet)
First story above or below grade plane and occupiable roofs over the first story above grade plane	A, Bb, E, Fb, M, U	49	75
First story above or below grade plane and occupiable roofs over the first story above grade plane	H-2, H-3	3	25
First story above or below grade plane and occupiable roofs over the first story above grade plane	H-4, H-5, I, R-1, R-2a, c_, R-2.2_	10	75
First story above or below grade plane and occupiable roofs over the first story above grade plane	I-2	7	50
First story above or below grade plane and occupiable roofs over the first story above grade plane	Sb, d	29	75
Second story above grade plane	B, F, M, Sd	29	75
Third story above grade plane and higher	NP	NA	NA
For SI: 1 foot = 304.8 mm. NP = Not Permitted. NA = Not Applicable. a. Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency escape and rescue openings in accordance with Section 1031. b. Group B, F and S occupancies in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or an occupiable roof of such build- ings shall have a maximum exit access travel distance of 100 feet. c. This table is used for Group R-2 occupancies consisting of sleeping units. For Group R-2 occupancies consisting of dwelling units, use Table 1006.3.4(1). d.

CBC § 903.2.1 Medium relevance — show source text
[F] 903.2.1 Group A. An automatic sprinkler system shall be provided throughout buildings and portions thereof used as Group A occupancies as provided in this section.

[F] 903.2.1.1 Group A-1. An automatic sprinkler system shall be provided throughout stories containing Group A-1 occupancies and throughout all stories from the Group A-1 occupancy to and including the levels of exit discharge serving that occupancy where one of the following conditions exists:
1. The fire area exceeds 12,000 square feet (1115 m [2] ).
2. The fire area has an occupant load of 300 or more.
3. The fire area is located on a floor other than a level of exit discharge serving such occupancies.
4. The fire area contains a multitheater complex.
[F] 903.2.1.2 Group A-2. An automatic sprinkler system shall be provided throughout stories containing Group A-2 occupancies and throughout all stories from the Group A-2 occupancy to and including the levels of exit discharge serving that occupancy where one of the following conditions exists:
1. The fire area exceeds 5,000 square feet (464 m [2] ).
2. The fire area has an occupant load of 100 or more.
3. The fire area is located on a floor other than a level of exit discharge serving such occupancies. 4. The structure exceeds 5,000 square feet (465 m [2] ), contains more than one fire area containing a Group A-2 occupancy, and is separated into two or more buildings by fire walls of not less than 4-hour fire-resistance rating without openings.
[F] 903.2.1.3 Group A-3. An automatic sprinkler system shall be provided throughout stories containing Group A-3 occupancies and throughout all stories from the Group A-3 occupancy to and including the levels of exit discharge serving that occupancy where one of the following conditions exists:
1. The fire area exceeds 12,000 square feet (1115 m [2] ).
2. The fire area has an occupant load of 300 or more.
3. The fire area is located on a floor other than a level of exit discharge serving such occupancies. 4. The structure exceeds 12,000 square feet (1155 m [2] ), contains more than one fire area containing exhibition and display rooms, and is separated into two or more buildings by fire walls of not less than 4-hour fire-resistance rating without openings.
[F] 903.2.1.4 Group A-4. An automatic sprinkler system shall be provided throughout stories containing Group A-4 occupancies and throughout all stories from the Group A-4 occupancy to and including the levels of exit discharge serving that occupancy where one of the following conditions exists:
1. The fire area exceeds 12,000 square feet (1115 m [2] ).
2. The fire area has an occupant load of 300 or more.
3. The fire area is located on a floor other than a level of exit discharge serving such occupancies.
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FIRE PROTECTION AND LIFE SAFETY SYSTEMS

[F] 903.2.1.5 Group A-5. An automatic sprinkler system shall be provided for all enclosed Group A-5 accessory use areas in excess of 1,000 square feet (93 m [2] ).
CBC § 25218.5 Medium relevance — show source text
Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8, and 25943, Public Resources Code.

SECTION 140.3—PRESCRIPTIVE REQUIREMENTS FOR BUILDING ENVELOPES

A building complies with this section by being designed with and constructed to meet all prescriptive requirements in Subsection (a) and the requirements of Subsection (c) and (d) where they apply.

(a) Envelope component requirements.
1. Exterior roofs and ceilings. Exterior roofs and ceilings shall comply with each of the applicable requirements in this subsection:
2025 CALIFORNIA ENERGY CODE 105

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE

COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY

A. Roofing products. Shall meet the requirements of Section 110.8 and the applicable requirements of Subsections i through ii: i. Nonresidential buildings: a. Low-sloped roofs in climate zones 1 through 16 shall have:
1. A minimum aged solar reflectance of 0.63 and a minimum thermal emittance of 0.75; or
2. A minimum solar reflectance index (SRI) of 75. Exception 1 to Section 140.3(a)1Aia: Wood-framed roofs in climate zones 3 and 5 are not required to comply with Section 140.3(a)1Aia if the roof assembly has a U -factor of 0.034 or lower. Exception 2 to Section 140.3(a)1Aia: Roof constructions with a weight of at least 25 lb/ft [2] over the roof membrane are not required to comply with Section 140.3(a)1Aia. Exception 3 to Section 140.3(a)1Aia: An aged solar reflectance less than 0.63 is allowed provided the maximum roof/ceiling U -factor in Table 140.3 is not exceeded. b. Steep-sloped roofs:
3. in Climate Zones 1 and 3 shall have a minimum aged solar reflectance of 0.20 and a minimum thermal emittance of 0.75, or a minimum SRI of 16.
4. in Climate Zones 2 and 4 through 16 shall have a minimum aged solar reflectance of 0.25 and a minimum thermal emittance of 0.80, or a minimum SRI of 23.
ii. Guest rooms of hotel and motel buildings: a. Low-sloped roofs in Climate Zones 9, 10, 11, 13, 14 and 15 shall have a minimum aged solar reflectance of 0.55 and a minimum thermal emittance of 0.75, or a minimum SRI of 64. Exception to Section 140.3(a)1Aiia: Roof constructions with a weight of at least 25 lb/ft [2] over the roof membrane.

CBC § 180.2 Medium relevance — show source text

TABLE 180.2-A—ROOF/CEILING INSULATION TRADEOFF FOR LOW-SLOPED AGED SOLAR REFLECTANCE	Col2	Col3
MINIMUM AGED SOLAR REFLECTANCE	ROOF DECK CONTINUOUS INSULATIONR- VALUE (Climate Zones 6–7)	ROOF DECK CONTINUOUS INSULATION_R-_VALUE (Climate Zones 2, 4, 8–15)
0.60	2	16
0.55	4	18
0.50	6	20
0.45	8	22
No requirement	10	24

ii. Steep-sloped roofs in Climate Zones 4 and 8 through 15 shall have a minimum aged solar reflectance of 0.20 and a minimum thermal emittance of 0.75, or a minimum SRI of 16. Exception to Section 180.2(b)1Aii: The following shall be considered equivalent to Subsection ii: a. Buildings with ceiling assemblies with a U- factor lower than or equal to 0.025 or that are insulated with at least R-38 ceiling insulation in an attic; or b. Buildings with a radiant barrier in the attic, where the radiant barrier is not installed directly above spaced sheathing, meeting the requirements of Section 170.2(a)1C; or c. Buildings that have no ducts in the attic in Climate Zones 2, 4, 9, 10, 12 and 14; or d. Buildings with R-2 or greater continuous insulation above or below the roof deck. Exception 1 to Sections 180.2(b)1Ai and ii: Roof area covered by building integrated photovoltaic panels and building integrated solar thermal panels is not required to meet the minimum requirements for solar reflectance, thermal emittance or SRI. Exception 2 to Sections 180.2(b)1Ai and ii: Roof constructions with a weight of at least 25 lb/ft2 are not required to meet the minimum requirements for solar reflectance, thermal emittance or SRI. iii. For low-sloped roofs, the area of the roof recover or roof replacement shall be insulated to R-14 continuous insulation or a U- factor of 0.039 in Climate Zones 1, 2, 4, and 8 through 16. Exception 1 to Section 180.2(b)1Aiii: Roof recovers with new R-10 insulation added above deck do not need to be insulated to meet R-14.

Exception 2 to Section 180.2(b)1Aiii: When existing mechanical equipment located on the roof will not be disconnected and lifted, insulation added may be limited to the greater of R-10 or the maximum installed thickness that will allow the distance between the height of the roof membrane surface to the top of the base flashing to remain in accordance with the manufacturer’s instructions. Exception 3 to Section 180.2(b)1Aiii: At the drains and other low points, tapered insulation with a thermal resistance less than R-14 may be used, provided that insulation thickness is increased at the high points of the roof so that the average thermal resistance equals or exceeds R-14. Exception 4 to Section 180.2(b)1Aiii: The area of the roof recoat is not required to be insulated. B. Roof/ceiling insulation . i. Attic roof .

CBC § 10-14 Medium relevance — show source text

10-14 2025 CALIFORNIA FIRE CODE

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MEANS OF EGRESS

[BE] TABLE 1006.3.4(2)—STORIES AND OCCUPIABLE ROOFS WITH ONE EXIT OR ACCESS TO ONE EXIT FOR OTHER OCCUPANCIES	Col2	Col3	Col4
STORY AND OCCUPIABLE ROOF	OCCUPANCYe	MAXIMUM OCCUPANT LOAD PER STORY AND OCCUPIABLE ROOF	MAXIMUM EXIT ACCESS TRAVEL DISTANCE (feet)
First story above or below grade plane and occupiable roofs over the first story above grade plane	A, Bb, E, Fb, M, U	49	75
First story above or below grade plane and occupiable roofs over the first story above grade plane	H-2, H-3	3	25
First story above or below grade plane and occupiable roofs over the first story above grade plane	H-4, H-5, I, R-1, R-2a, c_, R-2.2_	10	75
First story above or below grade plane and occupiable roofs over the first story above grade plane	Sb, d	29	75
First story above or below grade plane and occupiable roofs over the first story above grade plane	I-2	7 occupants	50 feet
Second story above grade plane	B, F, M, Sd	29	75
Third story above grade plane and higher	NP	NA	NA
For SI: 1 foot = 304.8 mm. NP = Not Permitted. NA = Not Applicable. a. Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency escape and rescue openings in accordance with Section 1031. b. Group B, F and S occupancies in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or an occupiable roof of such build- ings shall have a maximum exit access travel distance of 100 feet. c. This table is used for Group R-2 occupancies consisting of sleeping units. For Group R-2 occupancies consisting of dwelling units, use Table 1006.3.4(1). d. The length of exit access travel distance in a Group S-2 open parking garage shall be not more than 100 feet. e. For Group L occupancies see Section 453.6.1 of the California Building Code.	For SI: 1 foot = 304.8 mm. NP = Not Permitted. NA = Not Applicable. a. Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and provided with emergency escape and rescue openings in accordance with Section 1031. b.

Frequently asked questions

Can I put any type of occupancy on a rooftop if I only want a small outdoor seating area?

Not automatically. §503.1.4 requires that the roof occupancy be an occupancy permitted above the story immediately below per Table 504.4, unless you meet the sprinkler/notification exception. If the occupancy is permitted (or you qualify under the exception), then apply all occupancy‑specific requirements (egress, fire protection, etc.).

Do occupiable roofs count toward building height or area limits?

Generally no — occupiable roof areas are not counted in building area under Section 506 and are not counted as an additional story for height/number‑of‑stories calculations under Section 504, subject to rooftop enclosures and penthouse rules. See §503.1.4.

How many exits does a rooftop event space need?

Calculate exits using the occupant load for the roof alone and then apply Table 1006.3.3: 2 exits for 1–500 occupants; 3 for 501–1,000; 4 for more than 1,000. Single‑exit allowances are narrow and depend on Tables 1006.3.4(1)/(2) by occupancy.

Can I reduce the structural live load for a rooftop garden?

Possibly. The code provides roof live‑load reduction rules specifically for occupiable roofs (see §1607.14.2). Those reductions are permitted only when the Chapter 16 criteria and formulas are correctly applied. Consult the structural provisions in Chapter 16.

What if I want high screens or a small enclosed room on the roof?

Enclosing elements over occupiable roof areas are generally limited to 48 inches in height above the roof surface (§503.1.4.1). Penthouses constructed per §1511 or roofs located more than 75 feet above fire‑department access are exceptions.

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