24 February 2014
Everything you always wanted to know about windows
The word ‘window’ was first recorded in the 13th century. Early windows were just holes in walls, sometimes covered with cloth, animal hide or wood, and later, shutters which opened and closed, giving some protection from the elements.
Mullioned windows followed later, and these transmitted light by means of many small pieces of glass joined by lead glazing bars and mullions, or vertical supports. They were expensive to produce and their optical quality was poor. Churches have some fine examples of this type of window, often using stained (coloured) glass portraying people or scenes from the Scriptures.
Plain glass windows became popular in the UK from the early 17th century, but because large sheets of glass were unavailable until the 1900s, multiple smaller panes were used, separated by wooden glazing bars, or ‘muntins’.
All these windows were single-glazed, so although they gave protection from the elements, they let in draughts and external noise, and created condensation.
Double Glazing Window Types
Fixed windows which cannot be opened, and whose function is merely to let in light, are the simplest. Often these windows (sometimes called ‘Clerestory’) are set in a high wall, or in a roof.
(A picture window is a modern, large version of a fixed window.)
Casement windows have always been common in the UK and Europe. They consist of various combinations of side-hung panels which are hinged to the frame at the side, smaller, top-hung (or ‘awning’) windows, and fixed panes.
In the early versions, the opening elements had plain hinges and a casement stay. They opened inwards and incorporated wooden shutters which opened outwards. The glass consisted of many small panes joined by wooden muntins, as described above.
Later casement windows used projection friction stays and espagnolette locking. The glass was usually a single sheet, although lattice windows can still be seen today in traditional architecture, where small panes of glass are arranged in a lattice pattern, separated by lead muntins.
Sash windows have single-hung, double-hung or horizontal-sliding varieties. They were very popular in Georgian and Victorian houses. The oldest surviving sash windows date from the 17th century. They comprise one or more moveable panels, or ‘sashes’ held in a wooden frame.
A Single-hung sash window has one moveable sash – (usually the bottom one) – while the other is fixed.
A Double-hung sash window comprises 2 sashes which overlap slightly and slide up and down inside a wooden frame. These windows were popular in the UK for many years, and can still be seen in many late Victorian and Edwardian suburban houses. The sashes were originally supported by counterweights held in a box on each side of the window, hidden inside the frame and attached by pulleys of rope, braided cord or chains.
More modern versions use spring balances to support the sashes, and they can be fitted with simplex hinges, allowing the window to be locked into the hinges on one side while the rope on the other side is detached. This enables the windows to be opened for cleaning, or to escape in the event of an emergency, such as a fire.
Horizontal-sliding sash windows have two or more sashes which overlap slightly, but slide horizontally within the frame.
Bay windows protrude from the wall, rising from the ground, and generally consist of three panes, two of which are set at an angle at the sides and one larger pane which is parallel to the wall. They let in more light than traditional, flat windows, and add space to a room.
Oriel windows are bay windows which do not extend to the ground, but are held in place by brackets.
Hopper windows are hinged at the bottom, and open outwards (as opposed to the awning windows mentioned above). They are often seen in older schools, and are useful for ventilation.
‘Tilt-and-Turn’ windows are invaluable for rooms where the windows can’t be reached from outside for cleaning. They either tilt inwards at the top, or open inwards from the hinges at one side. This enables them to be cleaned from inside the room.
Roof windows, or Skylights, often used in loft or basement conversions, are mainly used for light input. They are built into the roof structure and may be fixed or open, hung horizontally from the hinged top or pivoting around the centre.
Louvered (or ‘Jalousie’) windows comprise parallel slats of glass (or acrylic) which open and close horizontally, using a lever. They are often used in countries which have mild winters, as, although they cope well with rain, a good seal between the panes is impossible to achieve, so they have poor thermal insulation. Also, the slats can be removed easily, so they are not very secure.
In recent years, uPVC windows of all types have become popular. They replicate the aesthetic qualities of the originals, and overcome many of their disadvantages, such as rotting and distortion of the wood, the high maintenance involved in their upkeep, condensation and poor thermal and noise insulation. uPVC windows are available in a variety of colours and styles, from casement, bay and sash to fully reversible or ‘tilt-and-turn’, for easy cleaning, as described above.
Academy Home Improvements has a huge range of modern, double-glazed windows in many sizes, patterns and colours.
Academy has showrooms across the South-East including Reading, Maidenhead, Wokingham, Frimley, West Byfleet, Whitton and Basingstoke and has been providing experienced, friendly advice with no high-pressure sales to delighted customers for over 30 years.
Academy’s slogan: ‘Buy local – buy safe’ says it all.
Academy uses its own installers, rather than contracting the work out, so they always guarantee a top-quality job, conforming to FENSA standards.
Call Academy now for free advice on 0800 328 6698