Window Styles: How Each Type Works and Where It Fits Best

The right window style depends on the room, the wall and the house: sliders and hung windows suit most bedrooms and living areas, casements and awnings seal tightest and are easiest to reach over a counter, and picture windows give the most glass and the best energy performance. Match the style to the home's architecture, then check the rules that apply to specific spots: safety glass near tubs, showers, doors and low large panes, and emergency escape openings in bedrooms.

Window styles compared

Hung windows: double-hung and single-hung

Hung windows are the traditional vertical window. On a double-hung, both sashes move, so you can open the top for warm air to escape and the bottom for fresh air at the same time. Many double-hung windows tilt in so both sides of the glass can be cleaned from inside. Anlin's Coronado double-hung, for example, has both sashes tilting in. Single-hung windows move only the bottom sash and usually cost a little less.

Hung windows suit Victorians, Edwardians and craftsman homes, where the vertical proportions are part of the look. If you are keeping the period character, ask about grid patterns and the exterior trim profile, not just the sash.

Sliding windows

Sliders are the most common window in Bay Area ranch homes and post-war tracts. They are simple, affordable and good for wide, short openings. On a single slider one panel moves; on a double slider both do. Keep the tracks and weep holes clean, because sliders shed water through the sill. If you are replacing old aluminum sliders, a vinyl or fiberglass slider of the same size is the most direct swap.

Casement and awning windows

Casements are hinged on one side and crank open. They open nearly the full width of the sash, which gives the most ventilation and the largest clear opening for a given window size. When closed, the sash presses against its seals, so casements generally seal tighter than sliding windows. That helps with drafts and noise.

Awnings are hinged at the top and open outward from the bottom. Because the sash forms a small roof, they can stay cracked open in light rain. They work well high on a bathroom wall, or stacked above or below a picture window for ventilation.

A pair of casements opening from the center is often called a French window or French casement. The same look at floor level is a French door, which is a door, not a window, and follows door rules for safety glass.

Picture and floor-to-ceiling windows

Fixed windows don't open, which makes them the most airtight and usually the most energy-efficient choice per square foot. They are common in mid-century and modern homes and in stairwells. Large glass close to the floor has extra rules. Berkeley's window checklist, quoting the California Residential Code, lists safety glazing for an individual pane larger than 9 square feet when its bottom edge is less than 18 inches above the floor, its top edge is more than 36 inches above the floor, and there is a walking surface within 36 inches. Big west-facing glass also brings heat, so choose a low solar heat gain glass on those walls.

Bay, bow and garden windows

Bay and bow windows project out from the wall and add a little floor space and a lot of light. A bay usually has an angled picture window in the center with operable units on each side; a bow uses more units in a gentle curve. They need a small roof or cap, a seat board and proper support, and they must be flashed carefully into the siding.

Garden windows are small boxes with glass on the top and sides and shelves inside. Anlin describes its garden window as having side vents for ventilation and an adjustable shelf. They are popular over kitchen sinks for herbs and plants.

Sunrooms and walls of glass

Rooms with many windows overheat quickly in Concord, Livermore and San Jose summers and can feel cold on foggy coastal evenings. Choose glass by orientation: low SHGC on west and south walls, and a low U-factor everywhere. Mix fixed glass with casements or awnings so the room can be cross-ventilated. See our guide to window glass and energy ratings for what the numbers mean.

Room by room

Kitchens

Over a sink or counter, a casement or awning with a crank is easier to operate than a slider or hung window you have to lift while leaning over. Garden windows and wide picture windows with operable side units are other common choices. Check the clearance between the window and the faucet before choosing a crank style.

Bathrooms and showers

• Safety glass. Under California Residential Code section R308.4.5, as summarized in Berkeley's checklist, glass in walls or enclosures facing tubs, showers, spas and similar wet areas needs safety glazing when its bottom edge is less than 60 inches above the standing or walking surface. Glass more than 60 inches horizontally from the water's edge is exempt.
• Privacy. Obscure glass is the usual answer. Anlin, for example, offers several obscure patterns such as etch matte, rain and reed, plus optional tempered glass on all its windows.
• Ventilation. An awning set high on the wall lets steam out while keeping privacy. Still run the exhaust fan.
• Frames. Vinyl and fiberglass handle shower moisture better than painted wood. A window inside a shower needs a sill that sheds water and careful waterproofing around it.

Bedrooms

Every sleeping room needs at least one window that can serve as an emergency escape and rescue opening. Berkeley's checklist lists the California Residential Code minimums: 5.7 square feet of net clear opening (5.0 square feet within 44 inches of grade), at least 24 inches of clear height and 20 inches of clear width, and a sill no higher than 44 inches above the floor. Casements reach these sizes with the smallest window; sliders and hung windows only open halfway, so they need to be larger. Our egress window guide goes into detail.

Upper floors and stairs

Where an operable window opening is more than 72 inches above the ground outside, the California Residential Code calls for the lowest part of the opening to be at least 24 inches above the floor, unless the window has an approved opening limit or fall-prevention device. Glass beside stairs and landings often needs safety glazing too. Glass within a 24-inch arc of a door's edge and less than 60 inches above the floor generally needs safety glazing as well.

Color: white, bronze and black windows

Black and dark bronze frames are popular on modern farmhouse and contemporary re-sides, especially against white or light gray siding. Dark frames absorb more heat, so the material matters. Fiberglass holds dark colors well. On vinyl, choose a line made for dark exteriors, such as Anlin's ThermaCoat solar reflective colors or its Designer Black line. Some vinyl lines pair a dark exterior with a white interior only, so check the inside color before you order. Our frame materials guide compares the options.

Exterior trim

Trim frames the window and covers the joint between window and siding. It also does real work: the head trim and its flashing direct water away from the top of the window. Common looks include:

• Craftsman: wide flat casing with a thicker head piece that overhangs the sides.
• Traditional: brickmould or a molded profile. Some vinyl windows, including Anlin's, come with a brickmould frame option.
• Modern: narrow flat trim, or no trim with the siding finished tight to the frame.

On fiber cement re-sides, trim is usually fiber cement too, so it lasts as long as the siding. Our Oakland siding and trim project shows one approach.

Fire zones

In Fire Hazard Severity Zones, replacement windows have to meet California's wildfire-zone rules whatever the style. Berkeley's checklist lists accepted options for its hillside fire zones, including multi-pane glass with at least one tempered pane. Confirm with your building department.

How to choose

1. Start with the house style and keep it consistent on each elevation.
2. Use casements or awnings where you need to reach over something or want the tightest seal.
3. Check bedrooms for egress, and wet areas, doors and low large panes for safety glass.
4. Choose glass by orientation and noise exposure.
5. Decide on color and trim together with the siding.

Our window replacement team can review each opening with you and give a free written estimate.

Frequently asked questions

What is the most energy-efficient window style?

Fixed picture windows, because they have no moving parts or sliding seals. Among operable windows, casements and awnings generally seal tighter than sliders and hung windows. The glass package and NFRC ratings matter more than the style itself.

What is the difference between single-hung and double-hung windows?

On a single-hung window only the bottom sash moves. On a double-hung both sashes move, so you can open the top and bottom at once, and many tilt in for cleaning. Double-hung costs a little more.

Do bathroom windows need tempered glass?

Glass in walls or enclosures facing a tub or shower needs safety glazing when its bottom edge is less than 60 inches above the standing surface, unless it is more than 60 inches horizontally from the water's edge. Confirm with your building department.

Which window style is best for a bedroom egress window?

Casements, because they open almost fully and reach the required clear opening with a smaller window. Sliders and hung windows can also qualify, but they need to be larger since only half the window opens.

Can I change window styles when I replace windows?

Often, yes. If the opening size stays the same, a retrofit window in a different style can usually fit. Changing the size or adding a bay window requires framing work and a new construction install.

Sources

• City of Berkeley: Code Compliance Checklist, Windows and Doors (PDF)
• City of Berkeley: Code Compliance Checklist, Bathrooms and Laundry (PDF)
• Anlin: Coronado double hung window (glass, frame and color options)
• Anlin: Designer Black windows and doors