Windows types

Many types of windows have different characteristics (Figure 128) along with their own advantages and disadvantages. Common window terms are shown in Figure 129.

Fixed windows cannot be opened and are generally the least expensive. Though they usually offer the best level of energy efficiency and resistance to forced entry, fixed windows do not provide natural ventilation and cannot serve as a means of egress in case of fire.

Single- or double-hung windows open vertically. A single-hung window has only one operable sash (usually the bottom unit) and a double-hung window has both sashes operable. Because of their design, only half the window area can open for ventilation. Older hung windows were difficult to open or close and were prone to air leakage. Modern hung windows are much improved and provide good resistance to forced entry.

Horizontal and vertical slider windows are easy to operate and do not swing into or obscure living space. Similar to single-and double-hung windows, only half the window area of a slider can open for ventilation. Sliders tend to be less airtight than casement windows, awning and tilt-and-turn windows because their weatherstripping is subject to wear.

Figure 128

Common window types

Casement and awning windows swing open to the exterior and are among the more expensive types. They are very airtight and offer good resistance to forced entry. The entire window area can be open for ventilation. Casement windows are well suited to deflecting prevailing winds into the dwelling for natural ventilation and passive cooling. Awning windows have the advantage of shedding rain effectively when open.

Tilt-and-turn windows are the most flexible of all window types. Some can act like casement and awning windows. Similar to casements, the entire window area can be open for ventilation. These windows can be very airtight when fitted with compression-type closing devices.

Figure 129

Window terminology

Source : Canada Mortgage and Housing Corporation (CMHC)