CBC · California Building Code

What notations, load definitions and design basis are required?

The CBC requires that load types be identified using the Chapter 16 symbols (e.g., D, L, W, E) and that the designer declare the design method (strength/ASD, etc.). Designs must be checked either to factored (strength) loads or to nominal loads with allowable stresses; unusual loads need building‑official approval.

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Last reviewed: July 5, 2026

What the code requires

The CBC requires that Chapter 16 notations be used consistently so every load and load type on the structural documents is unambiguously identified (§1602). The code also requires that buildings be designed using one of the permitted design methods (strength/factored design, allowable stress, empirical, etc.) and be checked for either the factored (strength) loads or the nominal/allowable loads using the load combinations defined by the Code; uses or loads not covered must be approved by the building official (§1604.1, §1604.2).

Requirements in detail

1) Required notations (symbols you must use)

Chapter 16 provides the standardized symbols that must be used when identifying loads and load-related parameters on calculations and construction documents. Using these exact symbols avoids ambiguity between design teams, reviewers and the building official (§1602).

The most decision-relevant items from §1602 are:

Notation	Meaning (short)	When it matters	Code Reference
D	Dead load	Permanent weights (structure, fixed equipment) — always shown as basis for other loads	§1602
Di	Weight of ice (ASCE 7 Ch.10)	Cold-climate or exposed members subject to ice	§1602
E	Earthquake effect (ASCE 7 §12.4)	Seismic design basis, show source (ASCE 7)	§1602
F / Fa	Fluid or flood load / Flood load	Tanks, reservoirs, and flood-hazard designs	§1602
H	Earth, groundwater or bulk-material pressure	Retaining walls, buried structures	§1602
L	Live load	Occupancy floor loads and movable loads	§1602
Lr	Roof live load	Rooftop maintenance or storage loads	§1602
pg(asd), pg	Ground snow loads (ASCE 7 / figures/tables)	Snow load input to snow-load calculations	§1602
R	Rain load	Roof drainage and ponding checks	§1602
S	Snow load	Roof snow design and distribution checks	§1602
T	Self‑straining/cumulative effects	Long‑term strain/creep bookkeeping	§1602
V(asd), V	Allowable-stress design wind speed / Basic wind speed	Wind-pressure calculations and deflection checks	§1602
VT	Tornado speed (ASCE 7 Ch.32)	Tornado-design cases where applicable	§1602
W / Wi	Wind pressure / wind-on-ice	Lateral and component & cladding loads	§1602

Use the exact symbols on the cover sheet, load tables, and structural notes so the reviewer and permit files can unambiguously match loads to calculations (§1602).

2) Design-basis declarations and load definitions required by §1604

Section 1604 establishes what the designer must choose and how to declare it on the documents:

Permitted design methods: strength design (factored), load and resistance factor design, allowable stress design, empirical design or conventional construction methods — use the method allowed by the material chapter or referenced standard (§1604.1).
Strength requirement: buildings shall be designed to support the factored loads in the load combinations defined in this Code without exceeding strength limit states. Alternatively, designs may be done using nominal loads with allowable stresses in load combinations defined by this Code (§1604.2). State which basis (strength/factored or allowable) is used.
Items beyond chapter coverage (special occupancies or unusual loads) require building-official approval (§1604.2).
Serviceability: members must meet deflection/stiffness limits as indicated in Table 1604.3 and related subsections (§1604.3). State which serviceability criteria are applied (for example, which referenced standard or the table) on the plans.

Practical minimum design-basis statements to put on the drawings (derived from §1604 language):

"Design method: Strength design (LRFD) per CBC §1604.1; factored loads per CBC load combinations."
"Notation/key: D=dead load, L=live load, S=snow load, W=wind load, E=earthquake (ASCE 7 §12.4)."
"Serviceability criteria: deflection limits per CBC Table 1604.3 (or referenced material standard)."

Note: specific load values (e.g., ground snow from Figures or basic wind speeds from Figures) and numeric load‑combination factors are defined elsewhere in Chapter 16 (for example, the load‑combinations and maps/tables). The requirement to use factored vs. nominal loads is in §1604.2; the numeric combination factors are in the load-combination section and referenced standards, not in §1604 itself.

3) Recommended minimum items to appear on the structural cover sheet

(These are the items you should state explicitly so the design basis is clear; the requirement to choose a design method and address loads comes from §1604 and the notations from §1602.)

Design method chosen (strength/ASD/empirical) and reference standards (§1604.1, §1604.2).
A notation/key listing D, L, Lr, S, W, E, H, F, etc. consistent with §1602.
Source for hazard inputs (e.g., ASCE 7 figures/tables for V, S, E) — reference the specific figures/tables you used (the Code references those sources; you must show which ones you used).
Serviceability basis (Table 1604.3 or referenced standard) and any special deflection criteria applied (§1604.3).

Exceptions & special cases

If the use or occupancy creates loads or forces not specifically covered in Chapter 16 (for example unusual machinery loads, special process loads, exceptional flood or tsunami conditions), those loads and forces require the building official’s approval (§1604.2).
§1604.1 allows different permitted design methods per material chapter; some materials or referenced standards may restrict or prohibit certain methods (the material chapters and referenced standards control permitted methods) (§1604.1).
Chapter 16 also defines notation variants in the Chapter 16A material (where applicable) — be sure to use the chapter-specific notation if working in that appendix/chapter. The standard Chapter 16 notation list in §1602 is the primary source.

Common mistakes

Omitting the design method on the drawings (strength vs. allowable). §1604.1–§1604.2 require a clear basis.
Using nonstandard symbols or abbreviations (e.g., writing "G" for dead load) that conflict with §1602 notation — causes reviewer confusion and corrections. §1602.
Stating load magnitudes (e.g., snow, wind) without citing the source (figures/tables or ASCE 7) — §1602 identifies the parameters; the origin must be clear. §1602.
Applying serviceability limits without indicating which table or standard controls them (Table 1604.3 or referenced standards) — §1604.3.
Performing design for nominal/allowable stresses but failing to use the Code’s load combinations (or failing to note which method was used) — §1604.2.

Worked example — minimal, code‑grounded scenario (what to state and how to show numbers)

I cannot compute factored combination results here because the numerical load-combination factors and wind/snow maps are published elsewhere in Chapter 16 and ASCE 7; those numeric factors and maps were not retrieved for §§1602/1604. If you want the final factored numbers I can fetch the appropriate load‑combination section and hazard maps on request.

What you can and must show (concrete example values shown as input — not factored results):

Project: single-story office roof framing.
On the plans and calculations include:
- Design basis statement: "Design method: Strength design (LRFD) per CBC §1604.1; factored loads applied per CBC load combinations."
- Notation key (use §1602 symbols): "D = dead load; Lr = roof live load; S = snow load; W = wind; E = earthquake."
- Input (example, plainly shown as service/characteristic loads — these are the input magnitudes you document):
  - D = 12 psf (self‑weight + roofing assembly) — show how D was calculated.
  - Lr = 20 psf (roof live/maintenance load) — show source (table or code).
  - S (design snow input) = 30 psf (state the figure/table used to get this value).
  - W basic wind speed V = 115 mph (state which figure or ASCE 7 map used).
- Note: after listing inputs, add: "Factored/composite design loads to be taken from CBC load combinations (see §1605) and applied for strength limit states per §1604.2." (I did not compute the numeric factored combinations here because the load-combination coefficients are in §1605 and related tables.)

The critical point: show the characteristic (unfactored) inputs on the drawings using §1602 notation, and explicitly state the design method per §1604.1–§1604.2 so the reviewer knows whether they should expect factored (LRFD) calculations or allowable-stress calculations.

Related provisions (read these next)

Construction document requirements and what to show on plans: §1603 (construction documents) — shows what design loads and information must be indicated on the construction documents.
Load combinations (numerical factors and combinations you must use to form factored/nominal cases): §1605.
Serviceability and deflection limits (Table 1604.3 and subsections): §1604.3.
Snow loads (maps, figures and rules): §1608.
Wind loads (basic wind speed and maps): §1609.
Earthquake loads (reference to ASCE 7, Chapter 12/Section 12.4): §1613 and §1602 entries for E (see §1602 and ASCE 7 reference).

Code references

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

CBC § 1.10.2. High relevance — show source text
[OSHPD 2] - For applications listed in Section 1.10.2.

[OSHPD 5] - For applications listed in Section 1.10.5.

1601.1.4 Reference to other chapters. [DSA-SS/CC] Where reference within this chapter is made to sections in Chapters 17 and 18, the provisions in Chapters 17A and 18A respectively shall apply instead.

1601.1.5 Additional amendments. [DSA-SS/CC, OSHPD] 1. [OSHPD 1R, 2 & 5] In addition to the amendments in this chapter, these buildings shall comply with the requirements of Sections 1617A.1.1, 1617A.1.4, 1617A.1.11, 1617A.1.13, 1617A.1.18, 1617A.1.27, 1617A.1.39 and 1617A.1.41.

2. [DSA-SS/CC] See Section 1617 for additional requirements.

1601.2 Enforcement agency approval. [DSA-SS/CC, OSHPD 1R, 2 & 5] In addition to requirements of the California Administrative Code and the California Building Code, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the Registered Design Professional (RDP), are also subject to approval by the enforcement agency.

SECTION 1602—NOTATIONS

1602.1 Notations. The following notations are used in this chapter:

D = Dead load.

D i = Weight of ice in accordance with Chapter 10 of ASCE 7.

E = Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4 of ASCE 7.

F = Load due to fluids with well-defined pressures and maximum heights.

F a = Flood load in accordance with Chapter 5 of ASCE 7.

H = Load due to lateral earth pressures, ground water pressure or pressure of bulk materials.

L = Live load.

L r = Roof live load. p g(asd) = Allowable stress design ground snow load. p g = Ground snow load determined from Figures 1608.2(1) through 1608.2(4) and Table 1608.2.

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STRUCTURAL DESIGN

R = Rain load.

S = Snow load.

T = Cumulative effects of self-straining load forces and effects.

V asd = Allowable stress design wind speed, mph (m/s) where applicable.

V = Basic wind speed, V, mph (m/s) determined from Figures 1609.3(1) through 1609.3(4) or ASCE 7.

V T = Tornado speed, mph (m/s) determined from Chapter 32 of ASCE 7.

W = Load due to wind pressure.

W i = Wind-on-ice in accordance with Chapter 10 of ASCE 7.

SECTION 1603—CONSTRUCTION DOCUMENTS
CBC § 1601A.1.2 High relevance — show source text
centers.

1601A.1.2 Amendments in this chapter. DSA-SS and OSHPD adopt this chapter and all amendments.

Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopt- ing agency, as follows: 1. Division of the State Architect-Structural Safety:

[DSA-SS] – For applications listed in Section 1.9.2.1. 2. Office of Statewide Hospital Planning and Development:

[OSHPD 1] – For applications listed in Section 1.10.1.

[OSHPD 4] – For applications listed in Section 1.10.4.

1601A.2 Enforcement agency approval. In addition to the requirements of the California Administrative Code and the California Build- ing Code, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the Registered Design Professional (RDP), are also subject to approval by the enforcement agency.

SECTION 1602 A —NOTATIONS

1602 A .1 Notations. The following notations are used in this chapter:

D = Dead load.

D i = Weight of ice in accordance with Chapter 10 of ASCE 7.

E = Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4 of ASCE 7.

F = Load due to fluids with well-defined pressures and maximum heights.

F a = Flood load in accordance with Chapter 5 of ASCE 7.

H = Load due to lateral earth pressures, ground water pressure or pressure of bulk materials.

L = Live load.

L r = Roof live load.

p g(asd) = Allowable stress design ground snow load.

p g = Ground snow load determined from Figures 1608.2(1) through 1608.2(4) and Table 1608.2.

R = Rain load.

S = Snow load.

T = Cumulative effects of self-straining load forces and effects.

V asd = Allowable stress design wind speed, mph (m/s) where applicable.

V = Basic wind speed, V, mph (m/s) determined from Figures 1609 A .3(1) through 1609 A .3(4) or ASCE 7.

V T = Tornado speed, mph (m/s) determined from Chapter 32 of ASCE 7.

W = Load due to wind pressure.

W i = Wind-on-ice in accordance with Chapter 10 of ASCE 7.

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STRUCTURAL DESIGN

SECTION 1603 A —CONSTRUCTION DOCUMENTS

1603 A .1 General. Construction documents shall show the material, size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603 A .1.1 through 1603 A .1.10 shall be indicated on the construction documents.
CBC § 16-3 High 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 § 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:
1. Flood design class assigned according to ASCE 24.
2. In flood hazard areas other than coastal high hazard areas or coastal A zones, the elevation of the proposed lowest floor, including the basement.
3. 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.
4. 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 § 1.10.1. Medium relevance — show source text
[OSHPD 1R ] - For applications listed in Section 1.10.1.

[OSHPD 2] - For applications listed in Section 1.10.2.

[OSHPD 5] - For applications listed in Section 1.10.5.

2101.1.4 Reference to other chapters. [DSA-SS/CC] Where reference within this chapter is made to sections in Chapters 17 and 18, the provisions in Chapters 17A and 18A respectively shall apply instead.

2101.1.5 Additional amendments. [DSA-SS/CC] See Section 2115 for additional requirements.

2101.2 Design methods. Masonry shall comply with the provisions of TMS 402, TMS 403 or TMS 404 as well as applicable requirements of this chapter. [OSHPD 1R, 2 & 5] TMS 403 Not permitted by OSHPD.

2101.2.1 Masonry veneer. Masonry veneer shall comply with the provisions of Chapter 14.

2101.2.2 Prohibition. [OSHPD 1R, 2 & 5] The following design methods, systems and materials in TMS402/602 are not permitted by OSHPD:

1. Unreinforced masonry. 2. Autoclaved Aerated Concrete (AAC) Masonry. 3. Empirical design of masonry.

4. Adobe construction.

5. Ordinary reinforced masonry shear walls. 6. Intermediate reinforced masonry shear walls. 7. Prestressed masonry shear walls. 8. Direct design of masonry. 9. Design of masonry infill. 10. Prescriptive design of masonry partition walls. 11. Limit design method. 12. Glass fiber reinforced polymer (GFRP) reinforced masonry.

2101.3 Special inspection. The special inspection of masonry shall be as defined in Chapter 17, or an itemized testing and inspection program shall be provided that meets or exceeds the requirements of Chapter 17.

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MASONRY

SECTION 2102—NOTATIONS

2102.1 General. The following notations are used in the chapter:

NOTATIONS .

d b = Diameter of reinforcement, inches (mm).

F s = Allowable tensile or compressive stress in reinforcement, psi (MPa).

f r = Modulus of rupture, psi (MPa).

f s = Computed stress in reinforcement due to design loads, psi (MPa).

L s = Distance between supports, inches (mm).

l d = Required development length or lap length of reinforcement, inches (mm).

P = The applied load at failure, pounds (N).

S t = Thickness of the test specimen measured parallel to the direction of load, inches (mm).

S w = Width of the test specimen measured parallel to the loading cylinder, inches (mm).

SECTION 2103—MASONRY CONSTRUCTION MATERIALS
CBC § 2101A.1.2 Medium relevance — show source text
centers.

2101A.1.2 Amendments in this chapter. DSA-SS and OSHPD 1 & 4 adopt this chapter and all amendments.

Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopt- ing agency, as follows: 1. Division of the State Architect-Structural Safety:

[DSA-SS] For applications listed in Section 1.9.2.1. 2. Office of Statewide Hospital Planning and Development:

[OSHPD 1] - For applications listed in Section 1.10.1.

[OSHPD 4] - For applications listed in Section 1.10.4.

2101A.1.3 Prohibition. The following design methods, systems and materials in TMS 402/602 are not permitted by DSA-SS and OSHPD:

1. Unreinforced masonry. 2. Autoclaved aerated concrete (AAC) masonry. 3. Empirical design of masonry.

4. Adobe construction.

5. Ordinary reinforced masonry shear walls. 6. Intermediate reinforced masonry shear walls. 7. Prestressed masonry shear walls. 8. Direct design of masonry. 9. Design of masonry infill. 10. Prescriptive design of masonry partition walls. 11. Limit design method. 12. Glass fiber reinforced polymer (GFRP) reinforced masonry.

2101 A .2 Design methods. Masonry shall comply with the provisions of TMS 402 or TMS 404 as well as applicable requirements of this chapter.

2101 A .2.1 Masonry veneer. Masonry veneer shall comply with the provisions of Chapter 14.

2101 A .3 Special inspection. The special inspection of masonry shall be as defined in Chapter 17 A, or an itemized testing and inspection program shall be provided that meets or exceeds the requirements of Chapter 17 A .

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MASONRY

SECTION 2102 A —NOTATIONS

2102 A .1 General. The following notations are used in the chapter:

NOTATIONS .

d b = Diameter of reinforcement, inches (mm).

F s = Allowable tensile or compressive stress in reinforcement, psi (MPa).

f r = Modulus of rupture, psi (MPa).

f s = Computed stress in reinforcement due to design loads, psi (MPa).

L s = Distance between supports, inches (mm).

l d = Required development length or lap length of reinforcement, inches (mm).

P = The applied load at failure, pounds (N).

S t = Thickness of the test specimen measured parallel to the direction of load, inches (mm).

S w = Width of the test specimen measured parallel to the loading cylinder, inches (mm).

SECTION 2103 A —MASONRY CONSTRUCTION MATERIALS
CBC § 2101.3 Medium relevance — show source text
2101.3 Special inspection. The special inspection of masonry shall be as defined in Chapter 17, or an itemized testing and inspection program shall be provided that meets or exceeds the requirements of Chapter 17.

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MASONRY

SECTION 2102—NOTATIONS

2102.1 General. The following notations are used in the chapter:

NOTATIONS .

d b = Diameter of reinforcement, inches (mm).

F s = Allowable tensile or compressive stress in reinforcement, psi (MPa).

f r = Modulus of rupture, psi (MPa).

f s = Computed stress in reinforcement due to design loads, psi (MPa).

L s = Distance between supports, inches (mm).

l d = Required development length or lap length of reinforcement, inches (mm).

P = The applied load at failure, pounds (N).

S t = Thickness of the test specimen measured parallel to the direction of load, inches (mm).

S w = Width of the test specimen measured parallel to the loading cylinder, inches (mm).

SECTION 2103—MASONRY CONSTRUCTION MATERIALS

2103.1 Masonry units. Concrete masonry units, clay or shale masonry units, stone masonry units, glass unit masonry and AAC masonry units shall comply with Article 2.3 of TMS 602. Architectural cast stone shall conform to TMS 504. [OSHPD 1R, 2 & 5] Architec- tural cast stone construction shall be considered as an alternative system.

Exception: Structural clay tile for nonstructural use in fireproofing of structural members and in wall furring shall not be required to meet the compressive strength specifications. The fire-resistance rating shall be determined in accordance with ASTM E119 or UL 263 and shall comply with the requirements of Table 705.5.

2103.1.1 Second-hand units. Second-hand masonry units shall not be reused unless they conform to the requirements of new units. The units shall be of whole, sound materials and free from cracks and other defects that will interfere with proper laying or use. Old mortar shall be cleaned from the unit before reuse.

2103.2 Mortar. Mortar for masonry construction shall comply with Section 2103.2.1, 2103.2.2, 2103.2.3 or 2103.2.4.

2103.2.1 Masonry mortar. Mortar for use in masonry construction shall conform to Articles 2.1 and 2.6 A of TMS 602.

2103.2.2 Surface-bonding mortar. Surface-bonding mortar shall comply with ASTM C887. Surface bonding of concrete masonry units shall comply with ASTM C946.

2103.2.3 Mortars for ceramic wall and floor tile. Portland cement mortars for installing ceramic wall and floor tile shall comply with ANSI A108.1A and ANSI A108.1B and be of the compositions indicated in Table 2103.2.3.
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
For lumber and glued laminated timber members installed or used at all other moisture conditions or cross laminated timber and wood structural panels that
are dry at time of installation and used under dry conditions in accordance with the ANSI/AWC NDS, the creep component of the long-term deflection is permitted to be estimated
as the immediate dead load deflection resulting from_D_. The value of 0.5_D_ shall not be used in combination with ANSI/AWC NDS provisions for long-term loading.
e. The preceding deflections do not ensure against ponding. Roofs that do not have sufficient slope or camber to ensure adequate drainage shall be investigated for ponding.
See Chapter 8 of ASCE 7.
f. The wind load shall be permitted to be taken as 0.42 times the “component and cladding” loads or directly calculated using the 10-year mean return interval basic wind
speed,V, for the purpose of determining deflection limits in Table 1604_A_.3. Where framing members support glass, the deflection limit therein shall not exceed that specified
in Section 1604_A_.3.7
g. For steel structural members, the deflection due to creep component of long-term dead load shall be permitted to be taken as zero.
h. For aluminum structural members or aluminum panels used in skylights and sloped glazing framing, roofs or walls of sunroom additions or patio covers not supporting edge
of glass or aluminum sandwich panels, the total load deflection shall not exceed_l_/60. For continuous aluminum structural members supporting edge of glass, the total load
deflection shall not exceed_l_/175 for each glass lite or_l_/60 for the entire length of the member, whichever is more stringent. For aluminum sandwich panels used in roofs or
walls of sunroom additions or patio covers, the total load deflection shall not exceed_l_/120.
i._ l_ = Length of the member between supports. For cantilever members,l shall be taken as twice the length of the cantilever.
j. The snow load shall be permitted to be taken as 0.7 times the design snow load determined in accordance with Section 1608_A_.1 for the purpose of determining deflection
limits in Table 1604_A_.3.|

1604 A .3.1 Deflections. The deflections of structural members shall not exceed the more restrictive of the limitations of Sections 1604 A .3.2 through 1604A.3.9 or that permitted by Table 1604 A .3.

1604 A .3.2 Reinforced concrete. The deflection of reinforced concrete structural members shall not exceed that permitted by ACI 318.

1604 A .3.3 Steel. The deflection of steel structural members shall not exceed that permitted by AISC 360, AISI S100, ASCE 8, SJI 100 or SJI 200, as applicable.

1604 A .3.4 Masonry. The deflection of masonry structural members shall not exceed that permitted by TMS 402.

1604 A .3.5 Aluminum. The deflection of aluminum structural members shall not exceed that permitted by AA ADM.

1604 A .3.6 Limits. The deflection limits of Section 1604 A .3.1 shall be used unless more restrictive deflection limits are required by a referenced standard for the element or finish material.
CBC § 2.1 Medium relevance — show source text
2101 A .2.1 Masonry veneer. Masonry veneer shall comply with the provisions of Chapter 14.

2101 A .3 Special inspection. The special inspection of masonry shall be as defined in Chapter 17 A, or an itemized testing and inspection program shall be provided that meets or exceeds the requirements of Chapter 17 A .

2025 CALIFORNIA BUILDING CODE 21A-3

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

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MASONRY

SECTION 2102 A —NOTATIONS

2102 A .1 General. The following notations are used in the chapter:

NOTATIONS .

d b = Diameter of reinforcement, inches (mm).

F s = Allowable tensile or compressive stress in reinforcement, psi (MPa).

f r = Modulus of rupture, psi (MPa).

f s = Computed stress in reinforcement due to design loads, psi (MPa).

L s = Distance between supports, inches (mm).

l d = Required development length or lap length of reinforcement, inches (mm).

P = The applied load at failure, pounds (N).

S t = Thickness of the test specimen measured parallel to the direction of load, inches (mm).

S w = Width of the test specimen measured parallel to the loading cylinder, inches (mm).

SECTION 2103 A —MASONRY CONSTRUCTION MATERIALS

2103 A .1 Masonry units. Concrete masonry units, clay or shale masonry units, stone masonry units, glass unit masonry shall comply with Article 2.3 of TMS 602. Architectural cast stone shall conform to TMS 504. Architectural cast stone construction shall be considered as an alternative system.

Exception: Structural clay tile for nonstructural use in fireproofing of structural members and in wall furring shall not be required to meet the compressive strength specifications. The fire-resistance rating shall be determined in accordance with ASTM E119 or UL 263 and shall comply with the requirements of Table 705.5.

2103 A .1.1 Second-hand units. Second-hand masonry units shall not be reused unless they conform to the requirements of new units. The units shall be of whole, sound materials and free from cracks and other defects that will interfere with proper laying or use. Old mortar shall be cleaned from the unit before reuse.

2103 A .2 Mortar. Mortar for masonry construction shall comply with Section 2103 A .2.1, 2103 A .2.2, 2103 A .2.3 or 2103 A .2.4.

2103 A .2.1 Masonry mortar. Mortar for use in masonry construction shall conform to Articles 2.1 and 2.6 A of TMS 602.

2103 A .2.2 Surface-bonding mortar. Surface-bonding mortar shall comply with ASTM C887. Surface bonding of concrete masonry units shall comply with ASTM C946.
CBC § 3.3.44.2 Medium relevance — show source text
Amend Section 3.3.44.2 and amend publications to read as follows:

3.3.44.2 Open Station.* A station that is constructed such that it is directly open to the atmosphere and smoke and heat are allowed to disperse directly into the atmosphere.

The following enclosed areas in open stations are permitted:

1. Ticket/pass booths not exceeding 150 square feet (13.9 m [2] ) in area. 2. Mechanical and electrical spaces typically not used for human occupancy and necessary for the operation of a fixed guideway transit system. Such spaces shall be limited to two per level. 3. Restrooms not exceeding 150 square feet (13.9 m [2] ) in area. A maximum of four restrooms are permitted per level.

Add a new definition as 3.3.44.3 to read as follows:

3.3.44.1.1 Underground Station. A station or portion thereof that is located beneath the surface of the earth or of the water.

Amend Section 5.2.2.1 to read as follows:

5.2.2.1 Building construction for all new enclosed stations shall be not less than Type IA, Type IB or Type IIA construction and shall not exceed in area or height the limits specified in the California Building Code Table 503, for the station configuration or as determined by fire hazard analysis of potential fire exposure hazards to the structure.

Add Section 5.2.2.1.1 –5.2.2.1.3 to read as follows:

5.2.2.1.1 Underground stations shall be a minimum Type IA or Type IB constructions.

5.2.2.1.2 Open stations may be of Type IIB construction and shall not exceed in area or height as required by Table 503 for Type IIA.

5.2.2.1.3 Open at grade stations may be of any construction type allowed by the California Building Code.

Delete Section 5.2.2.2.

Amend Section 5.2.4.3 to read as follows:

5.2.4.3 Ancillary Spaces. Fire resistance ratings of separations between ancillary occupancies shall be established as required by the California Building Code.

35-36 2025 CALIFORNIA BUILDING CODE

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

REFERENCED STANDARDS

Amend Section 5.2.4.3.1 to read as follows:

5.2.4.3.1 The following areas shall be separated by a two-hour fire barrier:

1. Electrical control rooms, auxiliary electrical rooms and associated battery rooms

2. Trash rooms

3. Train control rooms and associated battery rooms

4. Fan rooms

5. Emergency generator rooms

Amend Section 5.2.4.5 to read as follows:

5.2.4.5 Separation Between System and Nonsystem Occupancies.* All station public areas shall be fire separated from adjacent non-system occupancies by a one hour fire barrier, unless otherwise required by other provisions of the California Building Code.

Amend Section 5.3.1.1 to read as follows:
California Building Code Medium relevance — show source text
A109 Analysis and Design Procedure . . . . . . . APPENDIX A-10

A110 General Procedure . . . . . . . . . . . . . . . . . . APPENDIX A-10

A111 Special Procedure. . . . . . . . . . . . . . . . . . . APPENDIX A-11

A112 Analysis and Design . . . . . . . . . . . . . . . . . APPENDIX A-14

A113 Detailed Building System Design Requirements . . . . . . . . . . . . . . . . . . . . APPENDIX A-15

A114 Walls of Unburned Clay, Adobe or Stone Masonry. . . . . . . . . . . . . . . . . . . . APPENDIX A-17

CONTENTS

CHAPTER A2 EARTHQUAKE HAZARD REDUCTION IN EXISTING REINFORCED CONCRETE AND

REINFORCED MASONRY WALL BUILDINGS

WITH FLEXIBLE DIAPHRAGMS. . . . . . . . . . . . APPENDIX A-21

A201 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-21

A202 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-21

A203 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-21

A204 Symbols and Notations . . . . . . . . . . . . . . APPENDIX A-21

A205 General Requirements . . . . . . . . . . . . . . . APPENDIX A-21

A206 Analysis and Design. . . . . . . . . . . . . . . . . . APPENDIX A-22

A207 Materials of Construction . . . . . . . . . . . . APPENDIX A-23

CHAPTER A3 PRESCRIPTIVE PROVISIONS FOR SEISMIC

STRENGTHENING OF CRIPPLE WALLS AND SILL PLATE

ANCHORAGE OF LIGHT, WOOD-FRAME RESIDENTIAL BUILDINGS. . . . . . . . . . . . . . . . APPENDIX A-27

A301 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-27

A302 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-27

A303 Structural Weaknesses. . . . . . . . . . . . . . . APPENDIX A-28

A304 Strengthening Requirements . . . . . . . . . APPENDIX A-28

CHAPTER A4 EARTHQUAKE RISK REDUCTION IN WOOD-FRAME RESIDENTIAL BUILDINGS WITH

SOFT, WEAK OR OPEN FRONT WALLS . . . . . APPENDIX A-45

A401 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX A-45

Frequently asked questions

Do I have to use the exact symbols from §1602 on every sheet?

Yes. §1602 lists the standard notations (D, L, W, E, etc.) and those symbol definitions are the authorship standard; using them avoids review comments.

Must I say whether I used strength design or allowable-stress design on the cover sheet?

Yes. §1604 requires a design method (permitted methods in §1604.1) and §1604.2 requires design for factored loads or nominal/load‑and‑allowable stresses — state which was used.

Where do I get the numeric wind/snow values to put in my input table?

Numeric inputs come from the maps/tables in Chapter 16 (e.g., figures referenced for wind and snow) and ASCE 7; the §1602 notations identify the parameter, and the specific figures/tables provide values. Cite both on the drawings.

What if I have an unusual load (e.g., heavy process equipment) that’s not in the tables?

§1604.2 says loads/forces for occupancies or uses not covered in the chapter require the building official’s approval. Provide full load description, location, and calculations for review.

If I use allowable-stress design, do I still use CBC load combinations?

Yes — §1604.2 permits designing using nominal loads with allowable stresses but those loads must be combined using the load combinations defined by the Code (see load-combination provisions).

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