As useful as glass windows are, they are the most vulnerable part of your home. The California building code provides builders with minimum standards to protect homes and their residents from the risks of glass windows. Glass windows can shatter, crack and even explode as a result of fires, earthquakes and the actions of people.
Safety Plate Glass
The California building code requires the use of safety glazing or safety plate glass in areas subject to human impact. For example, windows placed within 2 feet of doors and where the bottom edge of the window is less than 60 inches above the walkway. Storm doors, exit and entrance doors also need safety plate glass installed.
Sliding Doors and Saunas
Sliding glass windows can be a hazard because people might run straight through them and cut themselves. All sliding windows and glazing in fixed and sliding panels must be made of safety glass. Glazing on doors, windows and walls for hot tubs, saunas, showers and whirlpools must also have safety glazing installed.
Art glass used in doors, sidelights and large windows is exempt from safety glazing requirements if it is leaded, decorated or carved in such a way as to make it clearly visible. The purpose of the building code is that people do not injure themselves from not seeing the glass or from breaking the windows to enter the property. However, glazing in shower enclosures is not free from safety glazing requirements. You can tell if a window is made of safety glass by the etching certifying it as a safety glass window in the bottom corner of the window.
Windows must also comply with energy-efficiency rules. Windows, skylights or sliding doors must have a glazing U-factor of less than 0.57 and a solar heat gain coefficient of less than 0.40. The U-factor of a window measures the energy-efficiency of a window. The lower the factor the better the energy efficiency of the window. The solar heat gain coefficient works similarly: The lower the coefficient, the less solar heat the window transfers, reducing the energy expenditure needed to cool your home in the summer.
- window image by Lee O'Dell from Fotolia.com