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 are not designed to be opened, serving only to allow light in and keep weather out. These are often a plain, rectangular pane of glass in a frame, but fixed panes with arched heads or semi-circular windows are common on period properties.
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 another 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. These vent and open into the house not outover like a conventional window, this makes cleaning them a breeze.
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. On modern PVCu Sliding Sash Windows the weights are replaced by a complicated spring system, which gives alot easier movement and the windows can be tilted in-over for cleaning purposes.
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.
Skylights, commonly know as Velux Windows, 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.
Skyvents, more commonly used for conservatory roofs, come with a winder mechanism and an extension pole, can also be fitted with an electric motor for ease of opening. This is a good addition to any conservatory roof.
Trickle Vents these can be fitted to windows and doors to allow ventilation without having to open the windows or doors.
Child Restrictors these can be fitted to windows to restrict the ammount of opening to a vent. Door restrictors, used to restrict the distance a door will travel when opening, can be adjusted onsite.