Hazardous Locations Requiring Safety Glazing Under the IRC

The International Residential Code treats eight zones in a home as hazardous locations requiring safety glazing under the IRC: glass in doors, glass next to doors, large low windows, guards and railings, glazing around wet areas, glazing along stairs and ramps, glazing at the bottom of a stairway, and overhead or sloped glazing. In each of these zones, ordinary annealed glass is not allowed. The pane must be tempered, laminated, or an approved rigid plastic that has passed a recognized impact test. Jurisdictions adopt different IRC editions on their own timelines, but the core hazardous-location rules have stayed largely consistent across recent cycles.

What Counts as Safety Glazing

Safety glazing is glass or plastic engineered to break in a way that reduces the chance of deep cuts. Tempered glass shatters into small, blunt granules. Laminated glass cracks but holds together because a plastic interlayer bonds the pieces in place. Approved rigid plastics such as polycarbonate are accepted in certain applications.

To qualify, the material must pass an impact test simulating a person falling into the glass. The IRC references two standards: CPSC 16 CFR Part 1201 and ANSI Z97.1. The federal CPSC standard has two tiers. Category I covers smaller glazed door panels (no single piece larger than 9 square feet) tested at a 150-foot-pound impact. Category II covers shower and bathtub enclosures, sliding glass doors, and larger door panels, and requires surviving a 400-foot-pound impact.¹

The two standards are not interchangeable everywhere. Glazing in doors and in enclosures for showers, bathtubs, hot tubs, saunas, and steam rooms must be tested under CPSC 16 CFR 1201. ANSI Z97.1 is permitted only as an alternative for glazing in the other hazardous locations, such as large windows and stairway-adjacent panels.²

Tempered is the default for most residential hazardous locations because it is affordable and breaks safely. Laminated costs more but stays intact as a barrier after breaking, which matters where containment matters: skylights, overhead panels, and glass guardrails.

Glass in Doors

Every glass panel in a door is a hazardous location. Swinging, sliding, and bifold doors are all covered, and it does not matter how small the glass pane is or where it sits within the door.² If there is glass in the door, it must be safety-rated. Builders typically use tempered glass here because it handles the constant vibration of use better than laminated.

Glass Adjacent to Doors

Sidelites, the narrow panels flanking an entry door, are hazardous because someone stumbling near a doorway can fall into them. Under R308.4.2, glazing next to a door is hazardous when both of these are true: the nearest vertical edge of the glass is within 24 inches of either vertical edge of the closed door, and the bottom exposed edge of the glass is less than 60 inches above the floor.

The IRC carves out several exceptions:

Decorative glazing, such as leaded or faceted glass.
An intervening wall or permanent structure between the door and the glass.
Glass in a wall perpendicular to the door plane on the latch side.
Doors leading to a closet or storage space no deeper than 3 feet; the adjacent glazing is then evaluated under the large-window test instead.
Glazing next to the fixed (non-sliding) panel of a patio door.

These exceptions are narrower than many builders assume. A decorative insert inside the door itself still needs safety glazing, because that pane is governed by the door rule, not the adjacent-glazing rule.

Large Windows

Not every window needs safety glazing. The IRC uses a four-part test, and all four conditions must be true at the same time:

The exposed area of the individual pane exceeds 9 square feet.
The bottom of the glass is less than 18 inches above the floor.
The top of the glass is more than 36 inches above the floor.
A floor, walkway, or other walking surface is within 36 inches of the glass, measured horizontally in a straight line.

If any single condition fails, the window is not classified as hazardous under this section.² The logic: a large floor-to-above-waist pane near a walking path can look enough like an opening that a person walks into it. A small pane, or one with its bottom edge well above the floor, does not create that illusion.

Guards and Railings

Glass used in any guard or railing in a residential building is automatically a hazardous location, regardless of pane size or height above the floor. This applies to structural baluster panels, where the glass itself supports the handrail, and to non-structural infill panels sitting between metal posts. There is no four-part test here: if the glass is part of a railing system, it needs safety glazing.

Structural glass baluster panels carry additional requirements. A top rail or handrail must be attached, and that rail must be supported by at least three glass panels so it stays in place if one breaks. The exception: if the glass balusters are laminated with two or more plies of equal thickness, the top rail attachment requirement is waived, because a broken laminated panel will hold together and continue functioning as a barrier.

Here the type of safety glazing matters as much as having it. Fully tempered glass that shatters and falls away would leave an open gap in a railing, which is exactly the hazard a guard is supposed to prevent. Laminated glass, or tempered-laminated combinations, is the practical standard for glass railings.

Wet Areas: Bathrooms, Pools, and Hot Tubs

The IRC groups wet-area glazing into a single provision covering bathtubs, showers, hot tubs, saunas, steam rooms, and indoor and outdoor swimming pools. Glass in walls, enclosures, or fences facing any of these features is a hazardous location when the bottom exposed edge of the glazing is less than 60 inches above the standing or walking surface.³

The 60-inch vertical threshold catches most residential bathroom glass. A standard shower surround runs 72 to 80 inches tall, so any glass in or around it will almost certainly have its bottom edge below the 60-inch line. The same goes for windows next to a bathtub.

One exception matters: glazing located more than 60 inches horizontally from the water’s edge of a bathtub, hot tub, spa, whirlpool, or pool is exempt.³ In a typical 5-by-8-foot bathroom, almost everything is within that 60-inch arc anyway. The exception matters most in larger bathrooms and pool rooms.

Wet-area glazing must be tested under CPSC 16 CFR 1201, not the ANSI Z97.1 alternative. Shower doors and bathtub enclosures are Category II, so they must survive the 400-foot-pound impact test.¹

Glazing Along Stairs, Ramps, and Landings

Falls on stairs happen with more speed and less control than falls on flat ground, so the IRC uses more generous distance thresholds here than for ordinary windows. Two separate provisions apply.

Alongside the Stairway (R308.4.6)

Glass alongside a stairway, a ramp, or a landing between flights is a hazardous location when the bottom exposed edge of the glazing is less than 36 inches above the adjacent walking surface. The measurement runs vertically from the tread, ramp slope, or landing to the bottom of the glass.

Two exceptions apply. Glazing positioned 36 inches or more horizontally from the walking surface is exempt. And a protective horizontal rail installed on the accessible side of the glass between 34 and 38 inches above the walking surface can substitute for safety glazing if the rail meets the structural and dimensional standards covered below.

At the Bottom of a Stairway (R308.4.7)

The landing at the bottom of a stairway gets its own rule because a person losing their balance on the last few steps carries real forward momentum. Glazing near this landing is hazardous when the glass is less than 36 inches above the landing and within a 60-inch horizontal arc measured from the bottom tread in any direction. That five-foot arc catches a lot of glass the general stairway rule would miss.

Skylights and Overhead Glazing

Glass installed at a slope of 15 degrees or more from vertical falls under the IRC’s skylight and sloped-glazing provisions. The concern is different from walls: overhead glass that breaks sends pieces falling directly onto the people below. The IRC addresses this through material requirements and, in some configurations, screen or containment options that catch fragments.

Laminated glass is the standard choice for skylights because it holds together after cracking. Tempered breaks into small pieces that are less dangerous individually, but a rain of granules from overhead can still injure. Some skylight assemblies use a tempered outer lite with a laminated inner lite. If you are replacing or adding a skylight, confirm the glazing type with your building department, because skylight rules interact with the structural load provisions for wind and snow as well.

The Protective Rail Exception

A properly installed horizontal rail can exempt glass from safety glazing requirements in certain locations, including large windows and stairway-adjacent glazing. The rail acts as a physical barrier that keeps a body from reaching the glass during a fall. To qualify, the rail must meet all of these specifications:

Installed 34 to 38 inches above the walking surface.
At least 1½ inches in cross-section height.
Capable of withstanding a horizontal force of 50 pounds per linear foot without deflecting into the glass.
Mounted on the accessible side of the glazing.

This exception is useful for large picture windows where safety-rated glass would be expensive or where a specific glass type matters for aesthetic reasons. The rail has to be a real structural element, not decorative trim. Inspectors check the attachment method and sometimes request engineering documentation for the load capacity. A flimsy bar screwed into drywall will not pass.

Labeling and Identification

Every pane of safety glazing in a hazardous location must carry a permanent manufacturer’s designation that stays visible after installation. The mark can be acid-etched, sandblasted, ceramic-fired, laser-etched, or embossed. It cannot be removable without being destroyed.² A peel-off sticker does not satisfy this requirement.

The designation identifies the manufacturer, the safety standard the glass was tested against (CPSC 16 CFR 1201 or ANSI Z97.1), and the glass type. Manufacturers typically place the mark in a corner where it is least noticeable but still accessible for inspection.

For non-tempered safety glazing such as laminated glass, the IRC allows a written certificate or affidavit in place of the permanent mark on the glass itself.⁴ This exception does not extend to tempered glass, which must always bear the permanent designation. The reasoning is practical: laminated glass can be verified by examining its edge, since the interlayer is visible, while tempered glass looks identical to annealed glass without the label.

If an inspector cannot find the permanent mark on tempered glass in a hazardous location, the glass may need to be replaced even if it actually is tempered. This comes up often on renovations where older safety glass has a worn or paint-covered label. Documenting the glass specifications during installation saves real trouble later.

Replacement Glass in Existing Homes

Safety glazing requirements are not limited to new construction. When you replace a window or glass pane in an existing home, the new glazing must comply with current rules if it sits in a hazardous location. A bathroom window installed with ordinary annealed glass decades ago must be replaced with safety-rated glass if it falls within the wet-area thresholds.

The trigger is the replacement itself. If you are not touching the glass, the code does not force you to retrofit existing windows. But the moment you swap a pane, the grandfather protection ends. This applies whether you are replacing a broken pane in an existing frame or installing an entirely new unit. For older homes with large single-pane windows near floor level, a single replacement can turn into a more expensive project than expected.

Why Non-Compliance Matters

Code violations involving safety glazing create real legal exposure. When someone is injured by glass that should have been safety-rated but was not, the code violation itself becomes strong evidence of negligence in a personal injury lawsuit. Courts have upheld liability claims against property owners for injuries caused by non-compliant glass in locations such as shower doors. For landlords, the exposure is greater still, since tenants injured by non-compliant glass have a clear negligence claim. The cost of replacing a single pane with tempered glass is trivial next to the medical bills and legal damages from a laceration caused by annealed glass breaking into shards.

1
eCFR. Safety Standard for Architectural Glazing Materials
2
Energy Star. AAMA Attachment A – 2015 IRC Requirements
3
International Code Council. Hazardous Locations Requiring Safety Glazing Under the IRC
4
International Code Council. Safety Glazing