Dormers Shed Light on Design

This architecture feature contributes form as well as function and can help pinpoint what style a house might be.

February 1, 2005

Dormers have been featured in American architecture since the late 1600s. Although they come in a variety of shapes and sizes, all dormers are windows with their own roof, which is set vertically into the roof of the building itself.

To see examples of what dormers look like, go to Dormer Types in the Architecture Guide.

Being able to recognize different types of dormers will give you a big clue to a home's architectural style—and will likely impress your clients in the process. Here are some of the most important points to remember for dormers, so the next time you see one of these "roof" windows you'll be able to call it by its true name.

Its History

The origin of dormers goes back centuries to French architect Francois Mansart (1598-1666), who introduced the Mansard style—known for its four-sided, double-pitched roof that has a lower slope that is especially steep. The deep rooflines embraced tall attic spaces that could serve as an additional floor of sleeping areas without exceeding prevailing Parisian height restrictions—if light and ventilation could somehow be introduced.

Solution: Mansart inserted a sequence of windows into the sloping roofs to make the attics habitable. This history is reflected in the name of the windows: "Dormer" comes from the French word dormir, which means to sleep.

Dormers have played a similar role in American residential construction. Modest single-story houses (like the simple but charming Cape Cods built from the 1600s through the 1950s) frequently used dormers to enhance interior space that would otherwise be good for little but storage. More elaborate homes of three and four stories, not at all unlike those going up today, often display a horizontal string of dormers at the roofline.

A less commonly seen dormer type, the wall dormer, locates the window flush with the wall plane above or through the cornice line. This establishes the dormer more as a vertically projecting wall element than as an elaboration of the roof. Unlike roof dormers, wall dormers tend to feature highly ornamental surrounds.

Dormer Details

Dormers take a variety of shapes, from simple to sophisticated:

  • Flat
  • Shed
  • Gabled
  • Pedimented
  • Hipped
  • Deck
  • Arched
  • Oval
  • Eyebrow
  • Inset
  • Composite (includes several of the above forms)

How Dormers Describe Style

All dormers, whether roof or wall, add texture and intricacy to exterior facades while bringing much needed light and air inside. So dormers of any type serve an important purpose.

Some dormer treatments almost undeniably describe particular styles. For example, you can be pretty certain when you see a steeply pitched gable dormer filled with multiple geometric panes and accented with cutout bargeboard ornament that the style is Gothic Revival. Exposed, extended rafter ends on a hipped dormer tend to signal Craftsman architecture.

But because dormers assume so many shapes, it helps to know the primary characteristics of various styles in order to identify a particular style. Dormer detective work is only part of the identification process.

A grasp of roof shapes and embellishments, wall materials and treatments, window types and arrangement, door shapes, porch/column configuration, and other exterior ornamental details can help put a house more definitively in one camp vs. another.

  • Gable dormers: Colonial Revivial, Georgian, Shingle, Queen Anne, Stick, Chateauesque, Tudor, and Craftsman, to name a few
  • Hipped dormers: Prairie, Shingle, Craftsman
  • Arched dormers: Second Empire, Beaux Arts, French Eclectic
  • Oval dormers: French Eclectic, Beaux Arts, possibly Italian Renaissance
  • Shed dormers: Craftsman, Arts & Crafts, Colonial Revival
  • Eyebrow dormers: Shingle, Romanesque, Queen Anne
  • Pedimented dormers: Georgian, Federal, Colonial Revival styles

Test Yourself

Imagine standing at the curb of a new listing. The house has two gabled dormers. From this information, can you tell what style it is? Probably not; so look more closely:

  • One or one-and-a-half stories tall
  • Central front door
  • Wood siding
  • Shutters
  • Virtually no exterior ornamentation

Referring back to the styles linked to gabled dormers, the simplicity of this residence might narrow the choices to Craftsman and some version of Colonial Revival. Now you notice that the roofline takes a gambrel shape. The Craftsman style calls for a hipped roof, a Colonial Revival/Cape Cod a gabled roof, leaving the gambrel pointing toward Colonial Revival/Dutch Colonial.

Assigning a specific architectural style can be as much an art as a science, and dormers alone won't always provide an accurate answer. But those dormers do provide a good place to begin.

Learn More

Architecture Guide: Dormers Types

About Architecture

Buffalo Architecture and History

Identifying American Architecture: A Pictorial Guide to Styles and Terms: 1600-1945 by John J.G. Blumenson (W. W. Norton & Co., Revised edition, 1990)

American Houses: A Field Guide to the Architecture of the Home by Gerald L. Forester (Houghton Mifflin Co., 2004)

What Style Is It? A Guide to American Architecture by, John C. Poppeliers (John Wiley & Sons, 1995)

American Homes: An Illustrated Encyclopedia of Domestic Architecture by Lester Walker (Black Dog & Leventhal Publishers, 2002)

freelance writer

Linda Legner is a freelance writer in Burr Ridge, Ill., who covers design, engineering, construction, and real estate topics for newspapers, magazines, and businesses. She can be reached at


Residential Styles & Structural Elements


Flat arches are either level or have a slightly curved arch. This arch has supportive voussoirs, which are wedge-shaped stones or bricks.