Probably the earliest recorded technical specification of a sliding sash window was done by Thomas Kinward, Sir Christopher Wren’s master joiner during the time he worked at Whitehall Palace. Amazingly, that’s around 1669! The oldest surviving examples of sash windows in the UK are at Ham House in Richmond in Surrey — these were installed in the 1670s.
As glass became more commonplace, the influence of the counterbalanced sash window spread far and wide and was still the most popular choice of window design in the UK until around the Second World War. It has had a huge influence on western architecture and can be found in nearly every style of English property since the late 17th century. So, what is all the fuss about?
Zero Hinges
The first thing to understand is that a sash window is never hinged so it cannot open in this way, it will only slide. A sash window has two sections which can slide up and down or side to side although the latter is less common. One window sits in front and the other behind and the sashes fit inside a track that runs along a second window frame attached to the house.
What does
Counterbalance mean?
The windows are counterbalanced by lead weights on cords which are concealed within the window frame. The weight connects by a braided cotton sash cord or chain that runs over a pulley at the top of the frame. Broken cords are an inevitability of living with sash windows and requires the disassembly of at least some of the window for repair. Modern sash windows are usually counterbalanced by springs rather than lead weights.
Double Hung and
Single Hung
A double-hung window design is where the two sashes can move up and down in the window frame. This style promotes airflow because if you open the top and the bottom in equal amounts, then warm air which is higher in the room can escape and cold air can be drawn in through the bottom thus providing a cooling effect.
Double-hung sash windows are also much easier to clean. A double-hung window where the upper sash is shorter than the lower is called a cottage window.
A single-hung window also has two sashes, but the top sash is usually fixed and only the bottom one slides.
What is the Check Rail?
On a double-hung window, the check rail is the part where the bottom part of the upper sash and the upper part of the lower sash come into contact. This is sometimes also called the middle of the window.
The Panes of Glass
Typically, the classic arrangement you will see in Georgian houses is three panes across by two up on each sash giving what is called a ‘six over six’ panel window. Georgian windows tend to be single hung so one sash is fixed.
Victorian sash windows began to depart from the classic Georgian pattern and there is far greater variation in size and the number of panes of glass. New technology allowed for the creation of larger panes of glass, desirable because the view is less obstructed so, in a workman’s cottage, a sash window might just have one large clear pane in each sash. These panes are often referred to by their traditional name as ‘lights’.
Venetian-style sash windows added an extra adornment to the traditional sash window design with two fixed glass panels on either side of the sashes, often seen in prosperous merchant’s houses as an indicator of style and wealth.
Usually, sash windows are single glazed just by virtue of their age if the windows are original and date to the property. New replicas can be constructed to hold thick glazing panels and these often imitate the glazing bars by just applying a strip to the surface of the glass to give the appearance of multiple small panes. Thankfully, now new glass technology means that period property owners can enjoy the beauty of their original sash windows without living in cold and draughty rooms. Single glazing is available which can offer all the thermal properties of triple glazing yet is thin and lightweight enough to fit into the narrow frames of a sash window.
Are sash windows
high maintenance?
Well, yes, they can be, so you have to learn to love your windows but the rewards in terms of style and aesthetic appeal are boundless. Understanding how a sash window is constructed will help you to take better care of this beautiful feature and keep them in good working order.
Challenges centre on managing the wooden frames which, like any wooden window, are prone to deterioration and rot as the wood absorbs moisture. Keeping an eye on the condition of the wood and making minor repairs and restoration as soon as you spot anything will prevent a bigger problem further down the line. Draught stripping can solve the classic sash window ‘rattle’ and make sure any fresh paintwork doesn’t stick the sash shut, a common problem compared to casement windows when refurbished.
We can offer advice and restoration on traditional sash windows using a blend of experience and craftmanship coupled with innovative materials and techniques that combine the very best of old and new. We also bespoke-design new wooden sash windows to fit any property in a wide range of shapes, styles and sizes plus we can fit new wooden sash windows into existing frames.
Contact us here to discover what we could do for your sash windows.