Safety & Compliance
Safety Glass Requirements: Where Tempered & Laminated Are Required
A comprehensive guide to building code requirements for safety glazing, including where tempered and laminated glass are required, how they differ, and what homeowners need to know for compliance and protection.
Key Takeaways
- ✓Building codes require safety glazing (tempered or laminated glass) in specific hazardous locations where human impact is likely
- ✓Hazardous locations include: glass within 24 inches of doors along the walking path, glass in shower and tub enclosures, glass adjacent to stairways, and large glass panels near floor level
- ✓Tempered glass is most common safety glazing—undergoes heat treatment to increase strength and break into small, relatively harmless cubes
- ✓Laminated glass uses plastic interlayer to hold glass together when broken—required for overhead glazing and some security applications
- ✓Safety glazing must be permanently labeled with manufacturer ID and appropriate standard marking (ANSI Z97.1 or CPSC 16 CFR 1201)
- ✓Many existing homes contain non-compliant glass installed before 1977—replacement is advisable for safety
- ✓Local codes may have more stringent requirements than national standards—verify local jurisdiction requirements
Quick Facts
- •Safety glazing has been mandatory in hazardous locations since 1977 per CPSC regulations
- •Hazardous locations include glass within 24 inches of doors, glass in shower/tub enclosures, and glass in stairways
- •Tempered glass is 4-5x stronger than annealed glass and breaks into small cubes rather than dangerous shards
- •Laminated glass holds together when broken due to plastic interlayer between glass layers
- •Thousands of Americans annually suffer glass-related injuries preventable with proper safety glazing
Safety Glass Requirements: Where Tempered & Laminated Are Required
Every year, thousands of Americans are injured by broken glass in their homes—many of these injuries could be prevented by proper safety glazing. According to the Consumer Product Safety Commission (CPSC), safety glazing requirements have been mandatory in "hazardous locations" since 1977, yet many homes still contain non-compliant glass that poses serious injury risks.
This guide explains where safety glass is required, the differences between tempered and laminated options, and what homeowners need to know when replacing windows and doors.
What Is Safety Glass?
The Problem with Standard Glass
According to the CPSC, annealed (standard) glass breaks into large, sharp shards that can cause severe lacerations. When someone falls against or through a glass panel, these shards can cause:
- Deep cuts requiring stitches
- Severed tendons or blood vessels
- Permanent scarring or disability
- In rare cases, fatal injuries
How Safety Glass Differs
According to ANSI Z97.1 (the American National Standard for Safety Glazing Materials), safety glass must either:
- Break safely: Shatter into small, relatively harmless pieces (tempered glass)
- Stay intact: Hold together when broken, preventing through-penetration (laminated glass)
Types of Safety Glazing
According to the FGIA, three main types of safety glazing meet code requirements:
Type | How It Works | Break Pattern
Tempered | Heat-treated for surface compression | Shatters into small, cube-like pieces
Laminated | Plastic interlayer bonds glass layers | Cracks but stays in frame
Wired | Wire mesh embedded in glass | Holds broken pieces together
Wired glass is primarily used in commercial fire-rated applications, according to GANA.
Building Code Requirements
The Governing Standards
According to the International Code Council (ICC), safety glazing requirements are established by:
- 16 CFR 1201: Federal CPSC standard (applies nationwide)
- ANSI Z97.1: Industry standard referenced by building codes
- IRC Section R308: International Residential Code (adopted by Idaho)
- IBC Chapter 24: International Building Code (commercial)
According to the Idaho Division of Building Safety, Idaho has adopted the 2018 IRC, which references these safety glazing requirements.
Where Safety Glass Is Required
According to IRC Section R308 and CPSC regulations, safety glazing is required in these "hazardous locations":
1. Doors and Door Sidelights
According to the IRC, safety glazing is required in:
- All glazing in doors: Including storm doors, sliding doors, and French doors
- Sidelights within 24" of doors: Glass panels beside entry doors
- Door transoms: When bottom edge is less than 60" from floor
The FGIA notes that this applies regardless of glass size—even small decorative lites in doors must be safety glazed.
2. Shower and Bathtub Enclosures
According to the IRC, safety glazing is required in:
- All shower doors and enclosures
- All bathtub enclosures
- Any glazing within 60" vertically of a shower pan or tub
- Any glazing within 60" horizontally of a water source
The CPSC emphasizes this is one of the most critical safety glazing locations—wet, slippery surfaces increase fall risk.
3. Near Stairs and Landings
According to the IRC, safety glazing is required:
- Within 60" horizontally of the bottom of stairs
- Within 60" horizontally of landings
- Where the walking surface is within 36" vertically of the glazing
- Glass is less than 60" above the walking surface
4. Near Swimming Pools and Hot Tubs
According to the IRC, safety glazing is required:
- Within 60" of pool/hot tub water's edge
- Less than 60" above the walking surface
- Through which the pool is visible
5. Large Glass Panels (General Rule)
According to the IRC and CPSC, safety glazing is required for any glazing that meets ALL of these criteria:
- Exposed area larger than 9 square feet
- Bottom edge less than 18" from floor
- Top edge more than 36" from floor
- Within 36" of a walking surface
This catches large fixed windows and full-height glass panels that someone could walk into or fall through.
Measuring for Compliance
According to GANA guidance, key measurements:
Measurement | Reference Point
Floor level | Finished floor, not subfloor
Walking surface | Any surface where people walk (includes decks, landings)
24" from doors | Measured from nearest door edge to nearest glazing edge
Glazing size | Visible glass area, not including frame
Tempered Glass
How It's Made
According to the FGIA, tempered glass is manufactured by:
- Cutting glass to final size (cannot be cut after tempering)
- Heating glass to approximately 1,150°F
- Rapidly cooling ("quenching") with air jets
- Creating surface compression and interior tension
Properties
According to ASTM testing standards, tempered glass:
- Is 4-5 times stronger than annealed glass of same thickness
- Shatters into small, cube-like pieces (typically less than 1/2")
- Cannot be cut or drilled after tempering
- Must be made to exact size before tempering
Advantages
According to the GANA:
- Strong: Resists breakage from impact
- Safe break pattern: Small pieces cause less severe injuries
- Heat resistant: Withstands thermal stress better than annealed
- Cost effective: Modestly higher cost than annealed
Limitations
According to the FGIA:
- Cannot be modified: No cutting, drilling, or edge work after tempering
- Spontaneous breakage: Rare but possible due to nickel sulfide inclusions
- No partial protection: Once broken, provides no barrier
- Security: Does not prevent through-penetration
Identifying Tempered Glass
According to CPSC requirements, all safety glazing must be permanently marked:
- Manufacturer's name or logo
- CPSC 16 CFR 1201 and/or ANSI Z97.1 certification
- Must be visible when installed
Look for etched marks in a corner of the glass.
Laminated Glass
How It's Made
According to the FGIA, laminated glass consists of:
- Two or more layers of glass
- Bonded together by a plastic interlayer (typically PVB—polyvinyl butyral)
- Heat and pressure fuse the assembly
Properties
According to ASTM testing standards, laminated glass:
- Cracks upon impact but stays in the frame
- Interlayer holds broken glass pieces together
- Continues to provide a barrier after breaking
- Can be cut before lamination but not after
Advantages
According to the GANA:
- Barrier retention: Maintains enclosure after breaking
- Security: Difficult to penetrate even when broken
- UV blocking: Interlayer blocks 99% of UV radiation
- Sound insulation: Better acoustic performance than single-pane
- Hurricane/impact rated: Used in storm-resistant glazing
Limitations
According to the FGIA:
- Higher cost: Significantly more expensive than tempered
- Weight: Heavier due to multiple layers
- Edge visibility: Interlayer may be visible at edges
- Delamination: Possible with age or improper installation
Laminated vs. Tempered: Which to Choose?
According to the GANA, both satisfy safety glazing requirements, but:
Application | Recommended Type | Reason
Shower doors | Tempered | Cost, water resistance
Entry door glass | Either | Tempered standard; laminated for security
Storm doors | Tempered | Cost, standard product
Skylights | Laminated | Prevents falling glass
Overhead glazing | Laminated (often required) | Code requirement in many jurisdictions
Hurricane zones | Laminated | Impact resistance
Security applications | Laminated | Break-in resistance
Special Considerations
Overhead Glazing
According to the IRC and IBC, overhead glazing (skylights, sloped glazing) has additional requirements:
- Laminated glass or tempered glass with screens below
- Prevents glass from falling on occupants if broken
- Idaho may have additional requirements for snow loads
Fire-Rated Glazing
According to the ICC, some locations require fire-rated glazing:
- Exit corridors
- Stairwell enclosures
- Fire-rated walls
Fire-rated glazing is a separate category from safety glazing, though some products are both, according to GANA.
Insulated Glass Units (IGUs)
According to the FGIA, in double or triple-pane windows:
- At least one lite must be safety glazed in hazardous locations
- Typically the indoor-facing lite is tempered
- Both lites may need to be safety glazed in some applications
Replacement Glass
According to the CPSC and IRC, when replacing glass:
- New glass must meet current code (even if original didn't)
- Hazardous location assessment is required
- Non-compliant replacement is a code violation
Cost Implications
Price Comparison
According to industry data compiled by GANA:
Glass Type | Cost vs. Annealed
Annealed (standard) | Baseline
Tempered | +15-25%
Laminated | +50-100%
Heat-strengthened | +10-20%
When Safety Glass Isn't Required But Makes Sense
According to the FGIA, consider voluntary safety glazing for:
- Children's bedrooms (play areas)
- Exercise rooms
- Any large glass panels in high-traffic areas
- Glass furniture (tabletops)
Code Enforcement and Liability
Permit Requirements
According to the Idaho Division of Building Safety, window replacement typically requires:
- Permit for structural changes (enlarging openings)
- Permit for egress window installation
- Compliance with safety glazing requirements regardless of permit status
Liability Concerns
According to legal guidance compiled by the FGIA, non-compliant glazing can create liability:
- Homeowner liability if someone is injured by non-compliant glass
- Disclosure issues when selling a home
- Insurance claim complications
- Contractor liability for improper installation
How to Verify Compliance
According to CPSC guidance:
- Look for permanent safety glazing marks (etched in corner)
- Check all hazardous locations identified above
- Have inspector verify during permit inspections
- Request documentation from contractor
For Homeowners: Key Takeaways
When Replacing Windows or Doors
According to the FGIA and GANA:
- Know the requirements: Ensure contractor specifies safety glazing where required
- Verify marking: Check for CPSC/ANSI certification marks
- Document installation: Keep records showing compliance
- Don't cut corners: Non-compliant glass creates liability and safety risks
When Assessing Existing Glass
According to CPSC guidance:
- Check for safety glazing marks in hazardous locations
- If marks aren't visible, assume glass may not be safety glazed
- Consider replacement if non-compliant glass is in hazardous locations
- Prioritize shower/tub enclosures, doors, and stair areas
The Bottom Line
According to the Consumer Product Safety Commission and International Code Council, safety glazing requirements exist because standard glass causes thousands of serious injuries annually. Understanding where safety glass is required protects your family and ensures your home meets building codes.
For Idaho homeowners:
- All door glazing and nearby sidelights require safety glass
- Shower and tub enclosures require safety glass
- Large panels near walking surfaces require safety glass
- Replacement glass must meet current codes
- Look for CPSC/ANSI certification marks to verify compliance
When in doubt, specify safety glazing. The modest cost premium is insignificant compared to potential injury risks and liability exposure. A qualified glazier can assess your home and ensure all glass meets applicable safety requirements.
Frequently Asked Questions
What are hazardous locations where safety glass is required?
The IBC and IRC define hazardous locations requiring safety glazing as: glazing in doors and within 24 inches of doors along the walking path where the bottom edge is less than 60 inches above the floor, glazing in shower and tub enclosures, glazing adjacent to stairways within 60 inches of the bottom tread, and glazing where the glass area exceeds 9 square feet with bottom edge less than 18 inches above the floor and top edge more than 36 inches above the floor. These locations have high impact probability.
What is the difference between tempered and laminated safety glass?
Tempered glass undergoes heat treatment that creates internal stress, making it 4-5 times stronger than annealed glass. When broken, it shatters into small, relatively harmless cubes. Laminated glass consists of two or more glass layers with a plastic interlayer (typically PVB) that holds glass fragments together when broken. Tempered glass is more common for windows and doors due to lower cost. Laminated glass is required for overhead glazing, provides better security and sound insulation, and is preferred where falling glass poses additional hazards.
How can I tell if existing glass is tempered?
Look for a permanent etched marking in one corner of the glass that includes the manufacturer name and the word 'tempered' or safety standard reference (ANSI Z97.1 or CPSC 16 CFR 1201). This marking is required by code and cannot be removed. If wearing polarized sunglasses, tempered glass may show a pattern of dark lines or spots due to internal stress patterns from tempering. If you can't find marking or stress patterns, the glass may not be tempered and should be replaced if in a hazardous location.
Do windows near doors always need to be tempered?
Not always—specific conditions must be met. Safety glazing is required for glass within 24 inches of a door along the walking path where the bottom edge is less than 60 inches above the floor. This means sidelites immediately adjacent to doors and windows within 24 inches on the same wall as the door typically require tempered glass. Windows across from doors, above 60 inches, or beyond 24 inches of the door may not require tempering. However, using tempered glass even when not required provides extra safety margin.
Should I replace old non-tempered glass in hazardous locations?
Yes, replacing non-tempered glass in hazardous locations is strongly recommended for safety even if not legally required for existing homes. Many homes built before 1977 contain annealed glass in locations that now require safety glazing. While you may not be forced to upgrade until you renovate, the injury risk remains real. Particularly prioritize glass in bathrooms, near doors, and in active areas where children play. Window glass replacement (just the glass panel) is typically $100-300 per window—a modest investment for significantly reduced injury risk.
Sources & References
Related Articles
Spontaneous Glass Breakage: Why Tempered Glass Sometimes Breaks on Its Own
Understanding why tempered glass can break without apparent cause, the science behind spontaneous breakage, and how to minimize risk.
Do Your Windows Have Safety Glass? How to Check
How to identify whether your existing windows have safety glass, what the markings mean, and what to do if they don't meet code.
Tempered vs. Laminated Glass: Understanding the Differences
How tempered and laminated glass differ, how each type fails, and when each is the appropriate choice for your application.
Where Is Safety Glass Required? A Homeowner's Guide
Understanding building code requirements for safety glass in homes—which locations require tempered or laminated glass and why.
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