Planning a bathroom renovation? Safety is just as important as style. When it comes to bathroom windows, using tempered glass isn’t just a smart choice—it’s often required by building codes. At Window World, we’re here to explain when bathroom windows must be tempered, what tempered glass is, and how it benefits your home’s comfort, safety and value. This comprehensive guide will help you understand the rules for your home so you can ensure every window is up to code.
What is Tempered Glass and Why is it Necessary?
Tempered glass is a type of “safety glass” that is heat-treated to be up to five times stronger than traditional glass. This treatment process not only increases its strength but also changes the way it breaks. If it does break, it shatters into small, rounded, pebble-like pieces, rather than large, dangerous shards. This minimizes the risk of serious injury from broken glass.
Tempered glass is especially beneficial in bathrooms because of its:
- Superior Safety: The small, dull pieces it breaks into are a major safety advantage, especially in a room where people are often barefoot.
- Increased Strength and Durability: It can withstand impacts, temperature fluctuations and the daily wear and tear that comes with a humid bathroom environment.
- Resistance to Weather: Its strength also makes it more resilient to damage from hail, high winds and flying debris, making it a great choice for any window exposed to severe weather.
- Low Maintenance: Its non-porous surface is easy to clean and maintain, which is perfect for a bathroom.
International Building Code: When Tempered Glass is Required
According to the International Residential Code (IRC), tempered glass is required in “hazardous locations,” which include bathrooms with bathtubs, showers, saunas and hot tubs. The code aims to prevent injuries from slip-and-fall accidents, so it focuses on two key measurements:
The 60-Inch Rule
- Vertical Rule: Any window or glazing with a bottom exposed edge that is less than 60 inches measured vertically above any standing or walking surface must be tempered. This applies to windows located directly in the tub or shower area.
- Horizontal Rule (The Arc): Any window that is within a 60-inch horizontal arc from the water’s edge of a tub, shower or hot tub is also considered a hazardous location and must be tempered.
- Important Exception: Glazing that is more than 60 inches horizontally from the water’s edge of a tub or shower is generally not required to be tempered.
Does a Window Behind a Toilet Need Tempered Glass?
This is a common question with a nuanced answer. The code specifically mentions “standing or walking surfaces,” and a toilet is a fixed fixture, not a surface for standing or walking. While some interpretations of the code might allow for a non-tempered window behind a toilet, many inspectors will still require tempered glass if the window falls within the 60-inch horizontal arc of a nearby tub or shower. To be safe, especially when a permit is involved, it is always a smart choice to install tempered glass to protect against all potential risks.
Other Areas Requiring Tempered Glass
Besides windows, tempered glass is typically required for:
- Shower doors and enclosures
- Glass panels near tubs
- Bathroom mirrors above a certain size
- Skylights
- Any large, low-to-the-ground windows near stairways, landings, or doors.
What is the Disadvantage of Tempered Glass?
While tempered glass offers superior safety and durability, it has one key disadvantage to keep in mind. Due to the heat-treating process, tempered glass cannot be cut, drilled or modified in any way after it has been manufactured. Any attempt to do so will cause the entire pane to shatter. This means all measurements for tempered glass must be precise before the glass is ordered and produced.
Frequently Asked Questions About Bathroom Windows and Tempered Glass
Explore Tempered Glass Options with Window World
Tempered windows can keep you relaxed and comfortable in all your living spaces. Window World’s window options are the best around for safety, energy efficiency and customization. Get started today with your free window estimate.