A Dormer is a framed space with one or more windows that juts out of a sloped roof.  The introduction of a dormer in a roof adds space in the sub-roof area (e.g., attic) and a visual component to a plain sloped roof.  

The roofing materials for dormers includes shingles, metal panels, shakes and tile.

The presence of a dormer introduces some dormer geometry complexity address in the calculators below.

Dormers

A dormer is a structural element on a roof that projects vertically from the main plane of the roof, creating additional space and usually incorporating a window. Dormers are often used to add natural light, ventilation, and headroom to attic spaces or upper floors of a building. They can also enhance the architectural character of a building. Dormers extend out from the slope of the roof, providing more usable space inside the building. Most dormers include a window, which allows light into the room and can offer views outside. The roof of a dormer can vary in style, with common types including gabled, hipped, shed, or flat roofs.

Types of Dormers:

1. Gabled Dormer: Features a pitched roof that forms a triangular gable. This is one of the most common dormer styles.
2. Shed Dormer: Has a flat or slightly sloping roof that slopes down in the same direction as the main roof but at a shallower angle.
3. Hipped Dormer: Has a roof with three sloping planes that meet at the top, similar to a hipped roof.
4. Eyebrow Dormer: Has a low, curved roof that resembles the shape of an eyebrow. It's more decorative and offers less space inside.
5. Flat Roof Dormer: Has a flat roof, offering a more modern and minimalist appearance.

Dormer Benefits: Dormers add headroom and usable floor space to upper levels, making attics or lofts more functional.  The windows in dormers bring in natural light, which can brighten up otherwise dark spaces. Dormer windows can be opened to allow fresh air into the space. Dormers can add architectural interest and character to a building, enhancing its curb appeal.