CBC · California Building Code
Loads & Load Combinations
Chapter 16 of the CBC defines required loads and directs use of ASCE 7 combinations or the CBC’s alternative ASD combinations (see §1605) for safe structural design.
Last reviewed: July 5, 2026
Overview
This area of the CBC lives in Chapter 16 (Structural Design) and covers required loads (dead, live, snow, wind, seismic, flood, soil, etc.) and how those loads must be combined for design. The chapter index and section list show the primary topics and sections, including §1601 (general), §1605 (load combinations), §1606 (dead loads), §1607 (live loads) through the specific hazard chapters such as §1608 (snow), §1609 (wind) and §1613 (earthquake) .
Load-combination rules in the CBC require designers to use the strength (LRFD) and allowable-stress (ASD) combinations in ASCE 7 (Sections 2.3 and 2.4), or the CBC’s alternative ASD combinations in §1605. Section §1605 also lists the common exceptions and clarifications (for example, treatment of snow, roof live loads, crane loads and stability checks) .
Practical requirements such as documenting special loads and design data on construction documents are covered elsewhere in Chapter 16 (for example the construction‑documents and special‑loads requirements in §1603), so designers must both select the correct combinations and show the load assumptions on the drawings and calculations .
In this section
Code references
Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:
CBC § 15-20 Medium relevance — show source text
1508 Roof Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-20
1509 Roof Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-20
1510 Radiant Barriers Installed Above Deck . . . . . . . . . .15-21
1511 Rooftop Structures . . . . . . . . . . . . . . . . . . . . . . . . . . .15-21
1512 Reroofing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-24
1513 [DSA-SS & DSA-SS/CC, OSHPD 1, 1R, 2, 4 & 5] Seismic Anchorage of Slate Shingle, Clay and Concrete Tile Roof Coverings. . . . . . . 15-25
INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX-1
HISTORY NOTE TO VOLUME 1 . . . . . . . . . . . . . . . . . . . . . .HIST-1
VOLUME 2
CHAPTER 16 STRUCTURAL DESIGN . . . . . . . . . . . . . . . . . .16-1
1601 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-3
1602 Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-3
1603 Construction Documents . . . . . . . . . . . . . . . . . . . . . . . 16-4
1604 General Design Requirements. . . . . . . . . . . . . . . . . . . 16-5
1605 Load Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-8
1606 Dead Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-9
1607 Live Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-10
1608 Snow Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-18
1609 Wind Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-24
1610 Soil Loads and Hydrostatic Pressure. . . . . . . . . . . .16-31
CBC § 0.5 Medium relevance — show source text
Taken at 0.5 x water depth_|1. A 30-second duration measured at a height of 33 ft.
2. Taken at 0.5 x water depth|TABLE 31F-3-9—BERTHING ANGLE Col2 VESSEL SIZE (DWT) ANGLE (degrees) Barge 15 < 10,000 10 10,000-50,000 8 >_ 50,000_ 6 3103F.7 Wind and current loads on structures.
3103F.7.1 General. This section provides methods to determine the wind and current loads acting on the structure directly, as opposed to wind and current forces acting on the structure from a moored vessel.
3103F.7.2 Wind loads. Chapter 29 of ASCE/SEI 7 [3.21] shall be used to establish minimum wind loads on the structure. Additional information about wind loads may be obtained from Simiu and Scanlan [3.22].
3103F.7.3 Current loads. The current forces acting on the structure may be established using the current velocities, per Section 3103F.5.3.
3103F.8 Load combinations. As a minimum, each component of the structure shall be analyzed for all applicable load combinations given in Table 31F-3-10 or Table 31F-3-11, depending on component type. For additional load combinations, see UFC 4-152-01 [3.18].
The “vacant condition” is the case wherein there is no vessel at the berth. The “mooring and breasting condition” exists after the vessel is securely tied to the wharf. The “berthing condition” occurs as the vessel impacts the wharf, and the “earthquake condition” assumes no vessel is at the berth, and there is no wind or current forces on the structure.
The use of various load types is discussed below:
31F-30 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MARINE OIL TERMINALS
3103F.8.1 Dead load (D). Upper and lower bound values of dead load are applied for the vacant condition to check the maximum moment and shear with minimum axial load.
3103F.8.2 Live load (L). Typically, the live load on MOTs is small and may be neglected for combinations including earthquake loads. However, in some cases, a higher value of live load may be warranted depending on MOT use, and an appropriate value of live load shall be considered for combinations including earthquake loads.
3103F.8.3 Buoyancy load (B). Buoyancy forces shall be considered for any submerged or immersed substructures (including pipe- lines, sumps and structural components).
3103F.8.4 Wind (W) and current (C) on the structure. Wind and currents on the vessel are included in the mooring and breasting condition. The wind and current loads acting on the structure are therefore additional loads that can act simultaneously with the mooring, breasting and/or berthing loads.
CBC § 16-3 Medium relevance — show source text
1601 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-3
1602 Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-3
1603 Construction Documents . . . . . . . . . . . . . . . . . . . . . . . 16-4
1604 General Design Requirements. . . . . . . . . . . . . . . . . . . 16-5
1605 Load Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-8
1606 Dead Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-9
1607 Live Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-10
1608 Snow Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-18
1609 Wind Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-24
1610 Soil Loads and Hydrostatic Pressure. . . . . . . . . . . .16-31
1611 Rain Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-32
1612 Flood Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-33
1613 Earthquake Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-34
1614 Atmospheric Ice Loads . . . . . . . . . . . . . . . . . . . . . . . .16-36
1615 Tsunami Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-36
1616 Structural Integrity . . . . . . . . . . . . . . . . . . . . . . . . . . .16-36
1617 Additional Requirements for Community Colleges [DSA-SS/CC] . . . . . . . . . . . . . 16-38
CHAPTER 16A STRUCTURAL DESIGN. . . . . . . . . . . . . . . . . 16A-1
1601A General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16A-3
1602A Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16A-3
CBC § 1605.1 Medium relevance — show source text
SECTION 1605—LOAD COMBINATIONS
1605.1 General. Buildings and other structures and portions thereof shall be designed to resist the strength load combinations specified in ASCE 7, Section 2.3, the allowable stress design load combinations specified in ASCE 7, Section 2.4, or the alternative allowable stress design load combinations of Section 1605.2.
Exceptions:
- The modifications to load combinations of ASCE 7, Section 2.3, ASCE 7, Section 2.4 and Section 1605.2 specified in ASCE 7 Chapters 18 and 19 shall apply.
16-8 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
STRUCTURAL DESIGN
Where the allowable stress design load combinations of ASCE 7, Section 2.4 are used, flat roof snow loads of 45 pounds per square foot (2.15 kN/m [2] ) and roof live loads of 30 pounds per square foot (1.44 kN/m [2] ) or less need not be combined with seismic load. Where flat roof snow loads exceed 45 pounds per square foot (2.15 kN/m [2] ), 15 percent shall be combined with seismic loads.
Where the allowable stress design load combinations of ASCE 7 Section 2.4 are used, crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind loads.
Where design for tornado loads is required, the alternative allowable stress design load combinations of Section 1605.2 shall not apply when tornado loads govern the design.
1605.1.1 Stability. Regardless of which load combinations are used to design for strength, where overall structure stability (such as stability against overturning, sliding, or buoyancy) is being verified, use of the load combinations specified in Section 2.3 or 2.4 of ASCE 7, and in Section 1605.2 shall be permitted. Where the load combinations specified in ASCE 7, Section 2.3 are used, strength reduction factors applicable to soil resistance shall be provided by a registered design professional. The stability of retaining walls shall be verified in accordance with Section 1807.2.3.
1605.2 Alternative allowable stress design load combinations. In lieu of the load combinations in ASCE 7, Section 2.4, structures and portions thereof shall be permitted to be designed for the most critical effects resulting from the following combinations. Where using these alternative allowable stress load combinations that include wind or seismic loads, allowable stresses are permitted to be increased or load combinations reduced where permitted by the material chapter of this code or the referenced standards. For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely to be in place during a design wind event shall be used. Where using these alternative load combinations to evaluate sliding, overturning and soil bearing at the soil-structure interface, the reduction of foundation overturning from Section 12.13.4 in ASCE 7 shall not be used. Where using these alternative basic load combinations for proportioning foundations for loadings, which include seismic loads, the vertical seismic load effect, E v, in Equation 12.4-4 of ASCE 7 is permitted to be taken equal to zero.
CBC § 1.1 Medium relevance — show source text
1.1_|||||||||X||X|X|||X|||||||||| |1601.1.2|||||||||X||X|X|||X|||||||||| |1601.1.3|||||||||X|||||||||||||||| |1601.1.4|||||||||X||X|X|||X|||||||||| |1601.1.5|||||||||X||X|X|||X|||||||||| |1601.2|||||||||X||X|X|||X|||||||||| |1603.1|||||||||||X|X|||X|||||||||| |Table 1604.5||||||||||||X|||X|||||||||| |1605.2|||||||||||X|X|||X|||||||||| |Table 1607.1|||||||||||X|X|||X|||||||||| |1607.9||||||X||||||||||||||||||| |1607.9.2||||||X|X|||||||||||||||||| |1607.12.4|X|||||||||||||||||||||||| |1607.14.3.5|||||||||||X|X|||X|||||||||| |1612.3.2|||||||||||X|X|||X|||||||||| |1613.1|||||||||||X|X|||X|||||||||| |1613.1.1|||||||||||||||||||||||X|| |1613.1.2|X|||||||||||||||||||||||| |1613.1.3|X|||||||||||||||||||||||| |1613.2|||||||||||X|X|||X|||||||||| |1613.4|||||||||||X|X|||X|||||||||| |1613.7|||||||||||X|X|||X|||||||||| |1617|||||||||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.
2025 CALIFORNIA BUILDING CODE 16-1
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
16-2 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
16 STRUCTURAL DESIGN
User notes:
About this chapter: Chapter 16 establishes minimum design requirements so that the structural components of buildings are proportioned to resist the loads that are likely to be encountered. In addition, this chapter assigns buildings and structures to risk categories that are indicative of their intended use. The loads specified herein along with the required load combinations have been established through research and service performance of buildings and structures. The application of these loads and adherence to the serviceability criteria enhance the protection of life and property.
ICC code development note: Code change proposals to this chapter will be considered by the IBC—Structural Code Development Committee during the
2025 (Group B) Code Development Cycle.
SECTION 1601—GENERAL
1601.1 Scope. The provisions of this chapter shall govern the structural design of buildings, structures and portions thereof.
CBC § 1603.1.7 Medium relevance — show source text
** The design load-bearing values of soils shall be shown on the construction documents. 1603.1.7 Flood design data. For buildings located in whole or in part in flood hazard areas as established in Section 1612.3, the documentation pertaining to design, if required in Section 1612.4, shall be included and the following information, referenced to the datum on the community’s Flood Insurance Rate Map (FIRM), shall be shown, regardless of whether flood loads govern the design of the building:
- Flood design class assigned according to ASCE 24.
- In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation of the proposed lowest floor, including the basement.
- In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation to which any nonresidential building will be dry floodproofed.
- In coastal high hazard areas and coastal A zones, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.
1603.1.8 Special loads. Special loads that are applicable to the design of the building, structure or portions thereof, including but not limited to the loads of machinery or equipment, and that are greater than specified floor and roof loads shall be specified by their descriptions and locations.
1603.1.8.1 Photovoltaic panel systems. The dead load of rooftop-mounted photovoltaic panel systems, including rack support systems, shall be indicated on the construction documents.
1603.1.9 Roof rain load data. Design rainfall intensity, i (in/hr) (cm/hr), and roof drain, scupper and overflow locations shall be shown regardless of whether rain loads govern the design.
SECTION 1604—GENERAL DESIGN REQUIREMENTS
1604.1 General. Building, structures and parts thereof shall be designed and constructed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods, as permitted by the applicable material chapters and referenced standards.
1604.2 Strength. Buildings and other structures, and parts thereof, shall be designed and constructed to support safely the factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other structures, and parts thereof, shall be designed and constructed to support safely the nominal loads in load combinations defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.
Loads and forces for occupancies or uses not covered in this chapter shall be subject to the approval of the building official.
1604.3 Serviceability. Structural systems and members thereof shall be designed to have adequate stiffness to limit deflections as indicated in Table 1604.3.
CBC § 2109.2.4.9 Medium relevance — show source text
Adobe 2109.2.4.9
Fire resistance 704.10 Masonry, wood support 2304.13 Liquefied Petroleum Gas Table 414.5.1,
415.9.2 Listed (definition) 202 Listing Agency (definition) 202 Live Load 1607
Construction Documents 1603.1.1
Posting of 106.1 Roof 1607
Live/Work Units 310.3, 508.5 Accessibility Chapters 11A and 11B Separation 508.2 Load and Resistance Factor Design (LRFD) 1602.1
Factored load 1604.2
Limit state 1604.2
Load combinations 1605 Wood design 2302.1, 2307 Load Combinations 1605 Allowable stress design 1605, 1605.2 Alternative allowable stress load
combinations 1605.2 Load and resistance factor design 1605 Strength design 1605 Loads 106, 202 Atmospheric ice 1614 Combinations 1605
Dead 1606
Factored load 402.8.2.1, 1604.2,
1709.2
Flood 1603.1.7, 1612 Impact 1607.12 Live 508.5.8, 1603.1.1, 1607 Load effects 1604.4
Nominal load 1604.2 Partial loading 1607.3.1, 1607.3.2 Rain 1603.1.9, 1611 Seismic 1603.1.5, 1613 Snow 1603.1.3, 1608 Soil lateral 1610
Tornado 1603.1.4, 1609.5, 1609.6.3.2 Tsunami 1615
Wind 1603.1.4, 1609 Lobbies Assembly occupancy 1030.4 Elevator 405.4.3, 1009.2.1, 1009.4, 3006, 3007.6, 3008.6 Exit discharge 1028.2 Underground buildings 405.4.3 Lobby 202 Local Enforcing Agency 1.8.3 Locks and Latches 1010.2, 1010.2.8 Delayed egress locks 1010.2.12 Electromagnetically locked 1010.2.10 Fire Exit Hardware 1010.2.10, 1010.2.8 Group I-2 407.4.1.1, 1010.2.13 Group I-3 408.4 High-rise 403.5.3 Sensor release 1010.2.11
Toilet rooms Chapter 29 Lodging Houses 310.4, 310.4.2 Lowest Floor 1603.1.7, 1612.4 Lumber
General provisions Chapter 23 Quality standards 2303
CBC § 405.2.3.1 Medium relevance — show source text
�
�
�
REPAIRS
- One- and two-family dwellings need not be evaluated or retrofitted for load combinations that include earthquake effects.
[BS] 405.2.3.1 Evaluation. The building shall be evaluated by a registered design professional, and the evaluation findings shall be submitted to the code official. The evaluation shall establish whether the lateral force-resisting system of the damaged building, including its foundation, if repaired to its predamage state, would comply with the provisions of the California Build- ing Code for load combinations that include wind effects, and with Section 304.3.2 of this code.
[BS] 405.2.3.2 Extent of repair for compliant buildings. If the evaluation establishes that the building in its predamage condition complies with the provisions of Section 405.2.3.1, then the damaged elements shall be permitted to be restored to their predamage condition.
[BS] 405.2.3.3 Extent of repair for noncompliant buildings. If the evaluation does not establish that the lateral force-resisting system of the building in its predamage condition complies with the provisions of Section 405.2.3.1, then the lateral forceresisting system, and its foundation, shall be retrofitted to comply with the provisions of this section. The wind loads for the repair and retrofit shall be those required by the building code in effect at the time of original construction, unless the damage was caused by wind, in which case the wind loads shall be in accordance with the California Building Code . The seismic retrofit shall comply with Section 304.3.2 of this code, but the earthquake loads shall not be less than those required by the building code in effect at the time of original construction.
[BS] 405.2.4 Substantial structural damage to gravity load-carrying components. Gravity load-carrying components that have sustained substantial structural damage shall be retrofitted to comply with the applicable provisions for dead, live and snow loads in the California Building Code . Undamaged gravity load-carrying components, including undamaged foundation components, that receive dead, live or snow loads from retrofitted components shall also be retrofitted if required to comply with these design loads.
[BS] 405.2.4.1 Lateral force-resisting elements. Regardless of the level of damage to vertical elements of the lateral forceresisting system, if substantial structural damage to gravity load-carrying components was caused primarily by wind or seismic effects, then the building shall be evaluated in accordance with Section 405.2.3.1 and, if noncompliant, retrofitted in accordance with Section 405.2.3.3.
Exceptions:
- Buildings assigned to Seismic Design Category A, B or C whose substantial structural damage was not caused by earthquake need not be evaluated or retrofitted for load combinations that include earthquake effects.
- One- and two-family dwellings need not be evaluated or retrofitted for load combinations that include earthquake effects.
[BS] 405.2.5 Substantial structural damage to snow load-carrying components. Where substantial structural damage to any snow load-carrying components is caused by or related to snow load effects, any components required to carry snow loads on roof framing of similar construction shall be repaired, replaced or retrofitted to satisfy the requirements of Section 1608 of the California Building Code .
CBC § 31F-30 Medium relevance — show source text
The “vacant condition” is the case wherein there is no vessel at the berth. The “mooring and breasting condition” exists after the vessel is securely tied to the wharf. The “berthing condition” occurs as the vessel impacts the wharf, and the “earthquake condition” assumes no vessel is at the berth, and there is no wind or current forces on the structure.
The use of various load types is discussed below:
31F-30 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MARINE OIL TERMINALS
3103F.8.1 Dead load (D). Upper and lower bound values of dead load are applied for the vacant condition to check the maximum moment and shear with minimum axial load.
3103F.8.2 Live load (L). Typically, the live load on MOTs is small and may be neglected for combinations including earthquake loads. However, in some cases, a higher value of live load may be warranted depending on MOT use, and an appropriate value of live load shall be considered for combinations including earthquake loads.
3103F.8.3 Buoyancy load (B). Buoyancy forces shall be considered for any submerged or immersed substructures (including pipe- lines, sumps and structural components).
3103F.8.4 Wind (W) and current (C) on the structure. Wind and currents on the vessel are included in the mooring and breasting condition. The wind and current loads acting on the structure are therefore additional loads that can act simultaneously with the mooring, breasting and/or berthing loads.
3103F.8.5 Earth pressure on the structure (H). The soil pressure on end walls, typically concrete cut-off walls, steel sheet pile walls on wharf type structures and/or piles shall be considered.
3103F.8.6 Mooring line/breasting loads (M). Mooring line and breasting loads can occur simultaneously or individually, depending on the combination of wind and current. Multiple load cases for operating and survival conditions may be required (see Sections 3103F.5.2 and 3105F.2). In addition, loads caused by passing vessels shall be considered for the “mooring and breasting condition.” Refer to Sections 3105F.2 and 3105F.3 for the determination of mooring line and breasting loads.
3103F.8.7 Berthing load (B e ). Berthing is a frequent occurrence, and shall be considered as a normal operating load. No increase in allowable stresses shall be applied for ASD.
3103F.8.8 Earthquake loads (E). Performance based seismic analysis methodology requires that the actual displacement demand be limited to defined strains in concrete, steel and timber. For the deck and pile evaluation, two cases of dead load (upper and lower bound) shall be considered in combination with the seismic load.
|TABLE 31F-3-10—LRFD LOAD FACTORS FOR LOAD COMBINATIONS [3.
CBC § 1617.3 Medium relevance — show source text
1617.3 Load combinations.
1617.3.1 Stability. When checking stability under the provisions of Section 1605.1.1 using allowable stress design, the factor of safety for soil bearing values shall not be less than the overstrength factor of the structures supported.
1617.3.2 Alternative allowable stress design load combinations. Where the alternative allowable stress design load combinations of Section 1605.2 are used, each load combination shall be investigated with one or more of the variable loads set to zero.
1617.3.3 Modifications to load combinations in ICC 300. Modify the text of ICC 300 as follows:
1617.3.3.1 ICC 300, Section 303.5.3. Modify Section 303.5.3 as follows:
The uniform live load, L, used in Equations 3-4 and 3-9 shall be permitted to be taken as zero when evaluating elements support- ing the handrail/guardrail provided those elements do not also support L.
1617.4 Roof dead loads. The design dead load shall provide for the weight of at least one additional roof covering in addition to other applicable loadings if the new roof covering is permitted to be applied over the original roofing without its removal, in accordance with Section 1512.
1617.5 Live loads.
1617.5.1 Modifications to Table 1607.1.
1617.5.1.1 Item 4. Assembly areas. The following minimum loads for stage accessories apply: 1. Gridirons and fly galleries: 75 pounds per square foot uniform live load. 2. Loft block wells: 250 pounds per lineal foot vertical load and lateral load. 3. Head block wells and sheave beams: 250 pounds per lineal foot vertical load and lateral load. Head block wells and sheave beams shall be designed for all tributary loft block well loads. Sheave blocks shall be designed with a safety factor of five.
4. Scenery beams where there is no gridiron: 300 pounds per lineal foot vertical load and lateral load. 5. Ceiling framing over stages shall be designed for a uniform live load of 20 pounds per square foot. For members supporting a tributary area of 200 square feet or more, this additional load may be reduced to 15 pounds per square foot (0.72 kN/m [2] ).
1617.5.1.2 Reserved.
1617.5.1.3 Item 4. Bleachers, folding and telescopic seating and grandstands. The minimum uniform live load for a press box floor or accessible roof with railing is 100 psf.
1617.5.1.4 Item 38. Yards and terraces, pedestrians. Item 38 applies to pedestrian bridges and walkways that are not subjected to uncontrolled vehicle access.
1617.5.1.5 Item 39. Storage racks and wall-hung cabinets. The minimum vertical design live load shall be as follows:
Paper media:
12-inch-deep (305 mm) shelf - 33 pounds per lineal foot (482 N/m)
16-38 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CBC § 2.3 Medium relevance — show source text
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
�
STRUCTURAL DESIGN
SECTION 1605 A —LOAD COMBINATIONS
1605 A .1 General. Buildings and other structures and portions thereof shall be designed to resist the strength load combinations specified in ASCE 7, Section 2.3, the allowable stress design load combinations specified in ASCE 7, Section 2.4, or the alternative allowable stress design load combinations of Section 1605 A .2. Exceptions:
The modifications to load combinations of ASCE 7, Section 2.3, ASCE 7, Section 2.4 and Section 1605 A .2 specified in ASCE 7 Chapters 18 and 19 shall apply.
Where the allowable stress design load combinations of ASCE 7, Section 2.4 are used, flat roof snow loads of 45 pounds per square foot (2.15 kN/m [2] ) and roof live loads of 30 pounds per square foot (1.44 kN/m [2] ) or less need not be combined with seismic load. Where flat roof snow loads exceed 45 pounds per square foot (2.15 kN/m [2] ), 15 percent shall be combined with seismic loads.
Where the allowable stress design load combinations of ASCE 7 Section 2.4 are used, crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind loads.
Where design for tornado loads is required, the alternative allowable stress design load combinations of Section 1605 A .2 shall not apply when tornado loads govern the design.
1605 A .1.1 Stability. Regardless of which load combinations are used to design for strength, where overall structure stability (such as stability against overturning, sliding, or buoyancy) is being verified, use of the load combinations specified in Section 2.3 or 2.4 of ASCE 7, and in Section 1605 A .2 shall be permitted. Where the load combinations specified in ASCE 7, Section 2.3 are used, strength reduction factors applicable to soil resistance shall be provided by a registered design professional. The stability of retaining walls shall be verified in accordance with Section 1807 A .2.3. When using allowable stress design, factor of safety for soil bearing values shall not be less than the overstrength factor of the structures supported.
1605A.1.2 Foundation resistance. [OSHPD 1 & 4] Strength design for foundation geotechnical capacity shall be in accordance with ASCE 7, Section 12.13.5 for all strength design load combinations, except that Resistance Factor (Ø) shall be permitted to be 1.0 for load combinations with amplified seismic forces in accordance with Section 1617A.1.15. Allowable stress design for founda- tion geotechnical capacity shall be in accordance with ASCE 7, Section 12.13.6 for all allowable stress design load combinations, and shall be established to be consistent with strength design requirements in ASCE 7, Section 12.13.5.
1605 A **.2 Alternative allowable stress design load combinations.
CBC § 1603.1.8 Medium relevance — show source text
1603.1.8 Special loads. Special loads that are applicable to the design of the building, structure or portions thereof, including but not limited to the loads of machinery or equipment, and that are greater than specified floor and roof loads shall be specified by their descriptions and locations.
1603.1.8.1 Photovoltaic panel systems. The dead load of rooftop-mounted photovoltaic panel systems, including rack support systems, shall be indicated on the construction documents.
1603.1.9 Roof rain load data. Design rainfall intensity, i (in/hr) (cm/hr), and roof drain, scupper and overflow locations shall be shown regardless of whether rain loads govern the design.
SECTION 1604—GENERAL DESIGN REQUIREMENTS
1604.1 General. Building, structures and parts thereof shall be designed and constructed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods, as permitted by the applicable material chapters and referenced standards.
1604.2 Strength. Buildings and other structures, and parts thereof, shall be designed and constructed to support safely the factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other structures, and parts thereof, shall be designed and constructed to support safely the nominal loads in load combinations defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.
Loads and forces for occupancies or uses not covered in this chapter shall be subject to the approval of the building official.
1604.3 Serviceability. Structural systems and members thereof shall be designed to have adequate stiffness to limit deflections as indicated in Table 1604.3.
TABLE 1604.3—DEFLECTION LIMITSa, b, c, h, i Col2 Col3 Col4 CONSTRUCTION _L or L_r _S j or W_f D + L d, g Roof members:e Supporting plaster or stucco ceiling l/360 l/360 l/240 Supporting nonplaster ceiling l/240 l/240 l/180 Not supporting ceiling l/180 l/180 l/120 Floor members l/360 — l/240 Exterior walls: With plaster or stucco finishes — l/360 — With other brittle finishes — l/240 — With flexible finishes — l/120 — Interior partitions:b With plaster or stucco finishes l/360 — — With other brittle finishes l/240 — — 2025 CALIFORNIA BUILDING CODE 16-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
STRUCTURAL DESIGN
Frequently asked questions
Which standard controls the load combinations I must use?
The CBC directs designers to use the strength load combinations in ASCE 7, Section 2.3, the allowable‑stress combinations in ASCE 7, Section 2.4, or the CBC alternative ASD combinations in §1605; the section also lists specific exceptions and modification rules .
Do I always combine snow and roof live loads with seismic loads?
No. §1605 allows exceptions under ASD: flat roof snow loads of 45 psf or less and roof live loads of 30 psf or less need not be combined with seismic; higher snow loads require a reduced fraction combined with seismic as specified in the section .
Where must I show special or equipment loads?
Special loads (machinery, PV arrays, unusual concentrated loads) must be specified on the construction documents so they can be included in load combinations and checks, per the construction‑documents provisions in Chapter 16 (see §1603.1.8) .
More in California Building Code
- Administration & Permits
- Energy Efficiency
- Existing Buildings
- Occupancy Classification & Use
- Hazardous Materials & Occupancies
- Types of Construction
- Fire-Resistance & Fire Safety
- Interior Finishes
- Means of Egress
- Accessibility
- Exterior Walls
- Roofing & Roof Assemblies
- Structural Design
- Special Inspections & Tests
- Foundations & Soils
- Concrete
- Masonry
- Steel
- Wood
- Elevators & Conveying Systems
Ask about the CBC
Get cited, plain-English answers on the California Building Code for your project — any code section, any scenario.
Start Free Trial