Introduction

Varying types of window are often differentiated by how they are opened. It is not unusual for a single window aperture to be filled by a frame that includes more than one type of window. So for example, a fixed pane is often positioned next to a casement sash, above which sits an awning light.

The opening part of any window is known as the 'sash'.

Fixed Windows

Hinged Windows

Hinged windows, usually mounted on butt hinges, are generally more airtight than sliding windows because the opening part of the window, or sash, presses firmly against the frame when it is closed.

In addition, almost the whole area of a hinged window can be opened, while a sliding window will only ever be able to open half of the window area.

• Casement windows are hinged at the side.
• Awning windows are hinged at the top.
• Hopper windows are hinged at the bottom.

Tilt & Turn windows are a recent addition to the market. These windows can be tilted open to ventilate the room as per a hopper, but can also be swung open like a casement window so that they can be cleaned on both sides.

Sliding Windows (Sash)

Horizontal sliders move along tracks positioned left to right. Both windows can move in a double-sliding window. One of a pair of windows slides in a single-sliding window.

Vertical sliders move up and down and are known as ‘boxsash’ windows. Both sashes can slide vertically in a double-hung boxsash. In a single-hung boxsash, only the bottom window can move vertically.

To prevent the two windows slipping downwards, lead weights are attached to each moving window via a system of cords and pulleys which are hidden inside the frame. These weights move in the opposite direction to the window to counterbalance it and thereby keep it still, and also make moving it easier.

Pivoting Windows

Windows mounted on central pivoting hinges are particularly useful as they can be swung through nearly 360 degrees, allowing them to be cleaned from the inside. This function features strongly in the building regulations, whereby a window is greater than 9m above the ground.

• Window requirements of the building regulations

Skylights mounted in the roof are regularly of this type, supplied with flashings to make the surrounding roof area water-tight.

A more basic form of pivoting window is the louvered window, which consists of several strips of unframed glass that are mounted at each end onto a mechanism that turns all of the strips simultaneously. These windows provide excellent ventilation, but are not particularly secure, and so tend to be used in hard-to-reach areas or on outbuildings.

Further information and useful links

• Types of glass
• Window frame materials
• Common sizes of window
• Window security
• Full list of windows & doors topics

• Find a Double Glazing supplier near you
• Find a Window Frame supplier near you
• Find a Skylight supplier near you
• Find a Sash Window supplier near you
• Find a Carpenter near you
• Find a Window Fitter near you