A reveal window is a window fitted into the side wall, or cheek, of a dormer, extension, or bay window, providing additional daylight and ventilation from a lateral direction.
Where reveal windows are used
Reveal windows are most commonly found in dormers. A dormer projects from the slope of a roof and has its own front wall and two side walls, known as cheeks. While the front wall typically holds the main window, a reveal window can be installed in one or both cheeks to bring in extra light from the side.
The same principle applies to extensions and bay windows where the side walls offer an opportunity for glazing. In all cases, the reveal window sits perpendicular to the main facade, catching light from a different angle than the front-facing windows.
Benefits of reveal windows
The primary advantage of a reveal window is improved natural light. Because it faces a different direction from the main window, it introduces light from a secondary angle, reducing dark corners and creating a more evenly lit interior. This is especially valuable in dormer rooms, which can otherwise feel enclosed.
Reveal windows also improve natural ventilation. Opening windows on two different walls creates cross-ventilation, which is more effective than relying on a single window. In addition, they can offer interesting sightlines that a front-facing window alone cannot provide.
Application
When planning a dormer or extension, including reveal windows should be considered early in the design phase. Their placement affects the structural framing of the cheek walls and must comply with building regulations regarding fire safety, privacy distances from neighbouring properties, and minimum daylight requirements.
Reveal windows come in various types, including fixed panes, top-hung casements, and side-hung casements. The choice depends on the available wall area, the desired ventilation, and aesthetic preferences. Proper flashing and weatherproofing around the reveal window frame are critical to prevent water ingress at the junction between the cheek wall and the roof slope.
Related terms
- Dormer window
- Cheek wall
- Daylight factor
- Cross-ventilation
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