door lite vs sidelite vs transom lite

Door Lite vs. Sidelite vs. Transom Lite

Doors | Frames | Life Safety

When it comes to doors, a lite is a glazed opening that allows light to pass through. Also referred to as vision lights or vision panels, they can be seen on both interior and exterior commercial openings. Lites vary in size and style and are a great way to add a sense of space and light to a room, especially when used on exterior openings. They also allow users to see through a door opening; this can prevent injuries from the swinging door when multiple users are traveling in opposite directions through the same opening. Depending on where the lite(s) are located on the door opening determines what they are called: a door lite, a sidelite, or a transom lite.

Door Lite

A door lite is a vision pane that is cut into a door. They come in multiple sizes and shapes. Typically, the glass is held in the opening with glazing stops. For wood doors, a wood molding is secured to the door on both sides of the glass to hold the door lite in place. For metal doors, a metal lite kit is used to sandwich the door and the glass together with a mechanical fastener. The glass in the lite is safety rated to meet Life Safety codes and can be fire rated if required. Door lites are typically stationary and cannot be opened.

Many types of glass can be glazed into a door. Normally, insulated tempered glass is used for energy efficiency on exterior doors with options including tinted, low e, argon gas, security, and decorative glass. For interior doors, clear tempered, laminated, frosted, decorative, polycarbonate, and different fire rated glass are available.

diagram for wood door lites, door lite, sidelite, mullion, door sidelite
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click to make larger


Sidelites are glazed openings located within the framed area immediately to one or both sides of a door opening. They are formed from the framing material and can be designed into multiple configurations, from a single glazed pane or multiple glazed panes divided by framing mullions. These architectural features help users see through the opening for safety and allow for light to pass through the opening, which helps the door opening to appear larger. Just like door lites, side lites cannot be opened, are safety rated, and are offered in the same fixed glazing options. Check out this blog for ADA regulations regarding door lites and sidelites.

Transom Lite

A glazed opening located above a door is called a transom lite. They are often combined with sidelites in a door opening. Unlike door lites and sidelites, transom lites can be fixed or operable. Operable transoms were originally used in historic buildings to control ventilation; opening the transom would allow for airflow into and throughout the building. Although they are occasionally still used for airflow, modern transom lites are usually fixed (cannot be opened) and purely decorative, allowing for more light to pass through the opening.

Lite Diagram

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Lites in any form are a great way to customize your commercial openings and add a sense of space and light. The experts at LaForce can help you decide on the opening that best fits your needs and ensure it meets current Life Safety, ADA, Fire, and Building codes. We can even create custom doors and frames in-house, whether you are undergoing new construction or a remodel. We can manufacture, design, or modify custom doors and frames in hollow metal, stainless steel, aluminum (modify only), wood (modify only), fire rated, and lead lined metal.

Learn more about all the ways LaForce can help you on your next project by visiting our What We Do page or by contacting one of our experts.