Window types by shape (C) Carson Dunlop AssociatesDictionary of Window Types & Architectures

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Complete photo dictionary of window types, architectural styles, designs:

This article provides a visual guide to identifying just about every type of window & window features. What is a dormer window, what is an eyebrow dormer? What is an oriel window?

What's the difference between a bay window and a bow window? What is a window pediment? What is a 6 over 12 window? What is a two over two window? What's the difference between a double hung and single hung window?

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Residential Building Window Types

Metal casement windows (C) Daniel Friedman

Common window types on residential buildings include the following:

[Click to enlarge any image]

Energy efficient window types sketch source: U.S. Department of Energy (left) shows traditional window styles used in North America.

The window types sketched above are included in our PHOTO GUIDE to WINDOW ARCHITECURE, Styles, Details, Features provided below in this article.

For information about window types, selection, installation, inspection, and repair, see our list of window articles beginning at WINDOWS & DOORS, Age, Types.

Also see SKYLIGHT LEAK DIAGNOSIS & REPAIR how to find the cause of leaks in rooftop skylights and other sloped glazing

A Quick Guide to Eyebrow Dormer Windows

Because there has been some confusion between eyebrow roof dormer windows and "eyebrow windows" we include here this excerpt from ROOF DORMER TYPES - Photo Guide.

Eyebrow window types (C) Daniel Friedman Eyebrow window types (C) Daniel Friedman Seneca Howland house windows (C) Daniel Friedman

Real estate agents, home inspectors, as well as building owners have often referred to the small second floor windows on antique colonial homes (photo at left) as "eyebrow" windows that we include these details to help sort out the confusion.

Our sketch and photos (above) show what an eyebrow window looks like.

Our third photo shows windows on the Seneca Howland house in Pleasant Valley NY (undergoing renovations by the author in the 1980's). Despite what your realtor tells you, these are not eyebrow windows. Windows in this design appear in these architectural styles: Greek Revival, Beaux Arts, Italian Renaissance.

Definition of Double-Hung and Single Hung Windows

Window sash types (C) Carson Dunlop Associates

At left the sketch, courtesy of Carson Dunlop Associates illustrates the difference between a single-hung window sash and a double-hung window.

As you can see, only the lower sash is movable in a single-hung window sash.


Complete Photo Guide to Window Architecture, Styles, Details, Features

Window Shape

Window Properties

Common Architectural Styles Where Used

Seneca Howland House Pleasant Valley NY (C) Daniel Friedman Attic story windows (3 windows set in white wood framed attic-level room, at left). In the U.S. in its colonial era property taxes were reduced in some colonies by avoiding constructing full-height windows on the top floor. Beaux Arts
Greek Revival (Seneca Howland House, Pleasant Valley, NY - see closeup, above)
Italian Renaissance
Seneca Howland House Pleasant Valley NY (C) Daniel Friedman

Awning Windows, operate by a crank and open outwards from the bottom, hinged at the sash top. Here is a photo of a modern awning type window observed in Buenos Aires.

A "hopper" window is essentially an awning window turned upside down (and is a design that catches rain and directs it indoors if the hopper window opens "out" towards the outside.

Modern. Also see WINDOW HARDWARE AGE and WINDOW EFFICIENCY Features & Ratings
Seneca Howland House Pleasant Valley NY (C) Daniel Friedman

Basement windows are set at or below ground level, often requiring a window well. Basement windows are not an architectural style per se, and may be designed as fixed, sliders, hoppers, awnings or other types of windows.

However because their location exposes basement windows to roof spillage, rain splash-up, snow (in some climates) as well as animals and insects, these installations need to be made of durable materials and properly installed and sealed to avoid building damage.

Seneca Howland House Pleasant Valley NY (C) Daniel Friedman Bay windows project out from the building wall and may incorporate both fixed vertical glazing and operable sashes of any type, usually double-hung or casement style. If the roof over a bay window is not maintained, or if the window is not properly installed, leaks and condensation are likely. This bay window uses fixed center glass and double hung sashes at either side. Also see Oriel & Bow windows. Modern, Victorian. Also see Oriel Windows. Also see WINDOW HARDWARE AGE and WINDOW EFFICIENCY Features & Ratings
Seneca Howland House Pleasant Valley NY (C) Daniel Friedman

Bow windows project out from the building wall and may incorporate both fixed vertical glazing and operable sashes of any type, though in the curved frame of a bow window the sash may also be specially constructed and glazed to follow that arc, or the operable units in the bow window may simply be small individual panes that operate as sliders or awnings.

At left our bow window, shown on a home in Boston, MA, is constructed with the bow extending to floor level. And at right is a smaller oriel window, also a bow but whose window opening does not extend to floor level.

Modern, Victorian. Also see Oriel Windows. Also see the same links as above for Bay Windows.
Second Empire window (C) Daniel Friedman Bracketed Window Tops

Empire style
Gothic Revival style
Italianate style
Second Empire (left, Main building, Vassar College, Poughkeepsie NY, James Renwick, 1865)

Second Empire window (C) Daniel Friedman

Casement Windows open outwards from hinges mounted at the window left or right vertical side.

This casement window photo shows an incompetent window replacement job - the windows cannot open because they hit the soffit overhang.

Modern. Also see WINDOW HARDWARE AGE and WINDOW EFFICIENCY Features & Ratings
Corner window design, Talesin West, photo (C) Daniel Friedman

Corner Windows on modern buildings require cantilevered support to permit the omission of a corner post. At left is corner window glazing installed by Frank Lloyd Wright at Talesin, West, AZ, at the request of his wife.

In older structures corner windows could be constructed as this ornate Boston MA corner window demonstrates.

Modern, Prairie School.
Second Empire window (C) Daniel Friedman Curved Sash, Curved Glass Windows - shown are curved sashes on a Boston MA home.

Gothic Revival style

Second Empire window (C) Daniel Friedman

Double Hung Windows. Both upper and lower window sashes can be moved in position.

See sketch at Definition of Double-Hung and Single Hung Windows

Also see Single Hung windows.

Nearly All, including Modern. Also see WINDOW HARDWARE AGE and WINDOW EFFICIENCY Features & Ratings
Empire style windows (C) Daniel Friedman Dormer windows, eyebrow dormer or peaked dormer windows are designs that set the window and surrounding structure into the building's roof as shown here. See eyebrow dormer below. Various
Empire style windows (C) Daniel Friedman Second Empire style window details, Vassar Campus, Poughkeepsie, NY Second Empire
Empire style windows (C) Daniel Friedman

Eyebrow windows or eyebrow dormers may be fixed or operable and are built protruding through the slope of a roof surface. Our photo shows an antique eyebrow window on a roof in New York state. Eyebrow windows may also appear as small peaked installations but the classic is rounded such as we show here. An "eyebrow" window is a miniature dormer in essence but requires less supporting framer than a larger dormer.

An eyebrow window is not a dormer or dormer window (see Dormers, above).

Fixed Glazing (C) Daniel Friedman Fixed glass or fixed glazing, shown on a home overlooking the Hudson River, NY

Modern, Praire, others.

Fortress windows, Alhambra Spain (C) Daniel Friedman

Fortress Windows, shown at left, the Ahlambra, Granada, Spain. Here is a similar keyhole-shaped window, also at the Alhambra.

Also see the musket slot "windows" in the top of the parapet wall above this ox-eye window at the Hacienda Tenexac in Tlaxcala, Mexico, ca 1532.

Gothic window (C) Carson Dunlop Associates Gothic Window styles. Here is a photo of gothic style windows and building details in Boston, MA.

Gothic Revival style

Sketch courtesy of Carson Dunlop Associates

Hood mold curved top windows (C) Carson Dunlop Associates Hood Top-mold Windows

Italianate architecture shown at left, Hood Top-mold style windows On Empire style Mansard, Vassar College, Poughkeepsie, NY

Jalousie louvered window (C) Daniel Friedman Jalousie or "louvered" windows - shown: Buenos Aires, Argentina apartment building window. Modern. Also see WINDOW HARDWARE AGE and WINDOW EFFICIENCY Features & Ratings
Label mold window (C) Daniel Friedman Label Top-mold Windows

French Eclectic
Gothic Revival (left) - Justin Smith Morrill Homestead, Vermont combines label top & Gothic window styles.
Tudor (rare)

(Photo wanted - Contact Us) Large Pane surrounded by smaller panes Queen Anne
Moorish window style (C) Daniel Friedman Moorish window styles, at left from the Alhambra, Granada, Spain. Here is a Moorish style window seen from the building interior, in Rabat, Morocco. North Africa, Southern Spain
Octagonal window, interior view (C) Daniel Friedman Octagonal Windows Modern & various.
Oval window (C) Daniel Friedman Oval Windows. Shown, Oval window, Boston MA. Also see round windows. Modern & Various
Oriel window (C) Daniel Friedman Oriel Windows - similar to a "bay" window but the framed-out window opening extends to the building's floor level. Victorian to Modern
Oriel window (C) Daniel Friedman Ox Eye Windows. See this exterior view of this ox-eye window at the Hacienda Tenexac in Tlaxcala, Mexico, constructed ca 1532, shortly after the arrival of Hernán Cortés de Monroy y Pizarro. European & New World, from ca 1530
Patterned window (C) Daniel Friedman Patterned Upper Pane, Blank Lower Queen Anne
Paired window design (C) Daniel Friedman Paired Windows. Shown, paired windows, Boston, MA. Italianate
many other uses
Palladian window (C) Carson Dunlop Associates Palladian combination. Also see our photos at Round-Top windows.

Palladian architectural style, also illustrated at ARCHITECTURE & BUILDING COMPONENT ID

Sketch courtesy of Carson Dunlop Associates

Broken pediment window (C) Carson Dunlop Associates Pediment Style, Broken Shape. Here is a photo of an ornate window pediment observed at the Alhambra, in Spain.

Gothic Revival

Sketch courtesy of Carson Dunlop Associates

Unbroken pediment window (C) Carson Dunlo Associatesp Pediment Style Windows, Unbroken. Here is a photo of a variation on the pediment style window from Barcelona, Spain.

Beaux Arts
Colonial Revival
Italian Renaissance
Italianate (also see Second Empire)

Sketch courtesy of Carson Dunlop Associates

Bay window (C) Daniel Friedman Projecting Windows: Also see Bay windows. Bay windows include openings whose faces are comprised of straight lines.

left, Second floor bay window, Poughkeepsie NY (1900)
Bay windows, Pratt House, Vassar College, Poughkeepsie, NY

sketch of a bay window design, courtesy of Carson Dunlop Associates

Bow window (C) Carson Dunlop Associates Projecting Windows: Bow windows, similar to bay windows, are constructed in a curve. Here is a bow window photographed in Boston, MA. Sketch courtesy of Carson Dunlop Associates
Oriel window (C) Daniel Friedman

Projecting Windows Oriel.

Also see Oriel windows above in this table.

Additional example of a row of Oriel windows, Hudson NY.
Ribbon style casement windows (C) Daniel Friedman Ribbon Style Windows Craftsman

Round topped window (C) Daniel Friedman Round topped windows; arch topped windows. Also see Palladian. Various.
Pedimented round window, Spain (C) Daniel Friedman Round windows. Shown, an ornate pedimented round window, Spain. Modern, Gothic, & Various.
Single hung window sash (C) Daniel Friedman

Single-hung sashed windows. Only one of the two sashes, usually the lower unit, can be moved. The other window sash is fixed in place. Shown, Palmer House, Vassar College, Poughkeepsie, NY.

See sketch at Definition of Double-Hung and Single Hung Windows Also see Double-Hung windows.

Modern, Victorian, Colonial, others.
Sliding sash or bypass windows (C) Daniel Friedman Slider Style or "sliding sash" Windows, may also be referred to as "bypass sash" windows. Shown, 1920's vintage multi-paned sliding wood sash windows, Buenos Aires, Argentina. Gothic, Victorian, Various. Also see WINDOW HARDWARE AGE and WINDOW EFFICIENCY Features & Ratings
New skylight in copper roof Vassar College (C) Daniel Friedman Skylights are an example of sloped glazing, normally built into a roof surface. Our skylight photo shows a series of custom-built copper-clad skylights in a re-roofed section of a similar building, both on the Vassar College Campus in Poughkeepsie, NY.

Skylights may be operable for ventilation or fixed.

Stained glass (Victorian) windows (C) Daniel Friedman

Stained-Glass windows. Colored glass cut to form an image or pattern, secured in place by lead.

Shown: fixed stained glass windows on a Victorian architecture home in Poughkeepsie, NY. Here is a photo of a more ornately-framed stained glass window On a church in Barcelona, Spain.

Gothic, Victorian, Various.
Aluminum triple track storm windows (C) Daniel Friedman

Storm windows are additional windows, fixed or operable, that are hung or installed over the main window sash to reduce heat loss through the window.

Traditional wood-sashed storm windows hang from brackets above the window opening, are secured at their bottom by hooks and eyes or possibly external turnbuckles, and were designed to be removed completely and swapped for screens during warm weather.

A modern (usually aluminum) "triple-track" storm window incorporates a movable screen and upper and lower widow sashes, obviating the need for seasonal ladder-climbing.

Each layer of glazing added to a window cuts heat loss through the window glass by about one third, but if the window is drafty any energy savings will be lost until the drafts are found and sealed.


And see STORM WINDOW WEEP HOLES - why we need weep holes to avoid sill rot at storm windows

Various from Victorian era

Window Styles / Nomenclature by Window Pane Count in Each Sash - x over y sashes

Double hung window (C) Daniel Friedman

Here we a give a few of the very large number of window sash designs that are referred to according to the number of panes or "lights" in each sash (of an upper and lower sash pair), starting with a

Two over Two window sash (left)

x over y window nomenclature generally pertains only to window sashes in which one (or both) sashes open by sliding vertically.

Second Empire window (C) Daniel Friedman Six over six window sash Various
Single hung window sash (C) Daniel Friedman Eight over twelve window sash Various
Broken pediment window (C) Carson Dunlop Associates Twelve over twelve window sash design  

At Field Guides to North American House Architecture we list (and you can buy at Amazon) books we have found particularly helpful in identifying architectural styles, including: as this more extensive list of architectural styles: Folk Houses, Native American Houses (U.S.), Pre-Railroad houses, National Architectural Styles (U.S.), Colonial Houses (1600-1820), Postmedieval English, Dutch Colonial, French Colonial, Spanish Colonial, Georgian, Adam, Early Classical Revival, Romantic Houses (1820-1880), Greek Revival style architecture, Gothic Revival style architecture, Italianate style architecture, Exotic Revivals style architecture, Octagon houses, Victorian style architecture Houses (1860-1900), Second Empire style architecture, Stick style architecture, Queen Anne style architecture, Shingle style architecture, Richardsonian Romanesque style architecture, Folk Victorian style architecture, Eclectic Houses (1880-1940), Anglo-American style architecture, English style architecture, and French Period Houses, Colonial Revival style architecture, Neoclassical style architecture, Tudor style architecture, Chateauesque style architecture, Beaux Arts style architecture, French Eclectic style architecture, Mediterranean Period Houses style architecture, Italian Renaissance style architecture, Mission style architecture, Spanish Eclectic style architecture, Monterey style architecture, Pueblo Revival style architecture, Modern Houses including Prairie style architecture, Craftsman style architecture, Modernistic style architecture, International style architecture, and American Houses Since 1940: Modern style architecture & Neoeclectic style architecture as well as unusual houses such as Mongolian Cloud (photo, Kuehn) houses and Underground Houses (photo, Roy).


Continue reading at WINDOWS & DOORS our home page for these building components, or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see ROOF DORMER TYPES - Photo Guide that includes roof dormer windows.

Or see WINDOWS & DOORS - home

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