Can’t tell a double hung from a double hernia? Then here in a nutshell are the most common window types, along with the architectural styles they’re usually associated with:
CASEMENT windows are hinged at the side and open like a door, usually toward the outside. In addition to being the oldest type of operable (openable) window, they’re also probably the simplest, most practical, and most adaptable. Casements are available in wood, clad wood, plastic, aluminum, and more rarely, in steel or bronze. They can be paired with one or both sash (the part that moves) operable, with or without a center mullion (the divider between individual window units). Casements can also be ganged together into long bands, as in Frank Lloyd Wright’s prairie houses. With appropriate muntins (what the window manufacturers refer to as “divided lites”), they’re suited to just about any architectural style, whether traditional or modern.
DOUBLE HUNG windows are another old-time standby. They have a pair of sash that slide vertically past each other, counterbalanced by cast iron weights in older examples and by springs in modern ones. Double hungs are widely available in wood, clad wood, and plastic. Shortcomings include balky operation when they get older and the inability to open more than half the window at a time. Many modern double hungs have a tilt sash feature that makes cleaning much easier than formerly. In some examples, known as single hungs, only the lower half opens.
Double hungs are mainly associated with American home styles such as Colonials, Victorians, bungalows, and early ranchers. They’re generally not suited to modernist designs or to European-derived revival styles such as Spanish, English, or Normandy.
HORIZONTAL SLIDERS have a pair of sash that slide horizontally past each other. They’re available in wood, clad wood, plastic, and aluminum. Sliders became very popular after World War II, when architectural styles such as the California rancher favored long, low horizontal proportions. Unlike double hungs, sliders don’t have to fight gravity, so they don’t require counterweights, but they have the same limitation of never being more than half openable.
AWNINGS have a sash hinged at the top that opens out, while HOPPERS have a sash hinged at the bottom that opens in. They’re often combined or “mulled” with a larger fixed window. They’re available in wood, clad wood, plastic, and aluminum. Both are mainly found in modernist designs, and will look out of place in most traditional architecture.
FIXED windows don’t open at all, and therefore can be had in just about any shape and any of the usual materials.
In general, clad wood windows are the most expensive, followed by wood, aluminum, and vinyl. And lastly, some caveats: Avoid using casements or awnings along exterior walkways or in other locations where people outside (especially frolicking kids) may run into them when they’re open. Remember that bedrooms have to have at least one emergency egress window with a sill is no higher than 44” from the floor, and which will allow a 21” diameter sphere to pass through it when open. Use special window shapes such as round tops, circles, or octagons in moderation, and don’t forget that it can be tough to find window coverings that will match their shape.