Chapter 24 — GLASS AND GLAZING
2403 General Requirements for Glass — 2025 California Building Code
California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-09-25 · California
CBSC: official editions, supplements and errata
Italicized text is a California amendment to the model code, as printed in the official publication.
Cite as: 2025 California Building Code (Title 24, Part 2) § 2403 · Effective January 1, 2026 · Official source: Building Standards Commission
2403.1 Identification.¶
Each pane shall bear the manufacturer’s mark designating the type and thickness of the glass or glazing material. The identification shall not be omitted unless approved and an affidavit is furnished by the glazing contractor certifying that each light is glazed in accordance with approved construction documents that comply with the provisions of this chapter. Safety glazing shall be identified in accordance with Section 2406.3.
Each pane of tempered glass, except tempered spandrel glass, shall be permanently identified by the manufacturer. The identification mark shall be acid etched, sand blasted, ceramic fired, laser etched, embossed or of a type that, once applied, cannot be removed without being destroyed.
Tempered spandrel glass shall be provided with a removable paper marking by the manufacturer.
2403.2 Glass supports.¶
Where one or more sides of any pane of glass are not firmly supported, or are subjected to unusual load conditions, detailed construction documents, detailed shop drawings and analysis or test data ensuring safe performance for the specific installation shall be prepared by a registered design professional.
GLASS AND GLAZING
2403.2.1 Additional Requirements. [DSA-SS, DSA-SS/CC and OSHPD 1, 1R, 2, 4 & 5] In addition to the requirements of Section 2403.2, glass supports shall comply with the following: 1. The construction documents and analysis or test data required per Section 2403.2 shall be submitted to the enforcement agency for approval. 2. Glass firmly supported on all four edges shall be glazed with minimum laps and edge clearances set forth in Table 2403.2.1. Exception: Single-story Type V skilled nursing or intermediate care facilities utilizing wood-frame or light-steel-frame construction.
| TABLE 2403.2.1—MINIMUM GLAZING REQUIREMENTS | |||||
|---|---|---|---|---|---|
| FIXED WINDOWS AND OPENABLE WINDOWS OTHER THAN HORIZONTAL SIDING | |||||
| Glass Area | Up to 6 sq. ft. | 6 to 14 sq. ft. | 14 to 32 sq. ft. | 32 to 50 sq. ft. | Over 50 sq. ft. |
| × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm |
| 1. Minimum Frame Lap | 1/4" | 1/4" | 5/16" | 3/8" | 1/2" |
| 2. Minimum Glass Edge Clearance | 1/8"1,2 | 1/8"1,2 | 3/16"1 | 1/4" | 1/4"1 |
| 3. Continuous Glazing Rabbet and Glass Retainer3 | Required | Required | Required | Required | Required |
| 4. Resilient Setting Material4 | Not Required | Required | Required | Required | Required |
| SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS | |||||
| Glass Area | Up to 14 sq. ft. | 14 to 32 sq. ft. | 32 to 50 sq. ft. | Over 50 sq. ft. | |
| × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm | × 0.0929 for m2, × 25.4 for mm |
| 5. Minimum Glass Frame Lap | 5. Minimum Glass Frame Lap | 1/4" | 5/16" | 3/8" | 1/2" |
| 6. Minimum Glass Edge Clearance | 6. Minimum Glass Edge Clearance | 1/8"2 | 3/16" | 1/4" | 1/4" |
| 7. Continuous Glazing Rabbet and Glass Retainer3 | 7. Continuous Glazing Rabbet and Glass Retainer3 | Required above third story |
Required | Required | Required |
| 8. Resilient Setting Material4 | 8. Resilient Setting Material4 | Not Required | Not Required | Required | Required |
1. Glass edge clearance in fixed openings shall not be less than required to provide for wind and earthquake drift.
2. Glass edge clearance at all sides of pane shall be a minimum of3/16 inch (4.8 mm) where height of glass exceeds 3 feet (914 mm).
3. Glass retainers such as metal, wood or vinyl face stops, glazing beads, gaskets, glazing clips and glazing channels shall be of sufficient strength and fixation to serve this purpose.
4. Resilient setting material shall include preformed rubber or vinyl plastic gaskets or other materials which are proved to the satisfaction of the building official to remain resilient.
2403.3 Glass framing.¶
To be considered firmly supported, the framing members for each individual pane of glass shall be designed so that the deflection of the edge of the glass perpendicular to the glass pane does not exceed 1/175 of the glass edge length where the glass edge length is not more than 13 feet 6 inches (4115 mm), or 1/240 of the glass edge length + 1/4 inch (6.4 mm) where the glass edge length is greater than 13 feet 6 inches (4115 mm), when subjected to the larger of the positive or negative load where loads are combined as specified in Section 1605.
2403.4 Interior glazed areas.¶
Where interior glazing is installed adjacent to a walking surface, the differential deflection of two adjacent unsupported edges shall be not greater than the thickness of the panels when a force of 50 pounds per linear foot (plf) (730 N/m) is applied horizontally to one panel at any point up to 42 inches (1067 mm) above the walking surface.
2403.5 Louvered windows or jalousies.¶
Float, wired and patterned glass in louvered windows and jalousies shall be not thinner than nominal 3/16 inch (4.8 mm) and not longer than 48 inches (1219 mm). Exposed glass edges shall be smooth.
Wired glass with wire exposed on longitudinal edges shall not be used in louvered windows or jalousies.
Where other glass types are used, the design shall be submitted to the building official for approval.
Get a plain-English answer with a citation back to this text.
Ask AI about this code