Woodstock Joinery Blog

There are many things that modern sash windows now do that save energy over the traditional single glazed sash window.

Double glazing and argon gas creates a barrier against the cold by reducing the thermal conductivity as compared to normal air.

There is Special glass called Low 'E' glass this keeps in heat in much more than normal glass, in addition there is a warm edge spacer bar between the glass along the edges this helps the internal glass to stay warm and lower thermal transmittance.

draft excluding strips - reduce and practically eliminate any draft between sashes this along with hard wood frame and sashes correctly installed with double glazed units can have a dramtic cost saving on your energy bill.

There is an unforeseen benefit to double glazing which in central London can be very welcome and that is the double glazing reduce traffic and external noise, achieving a decibel rating of 42db.

If having your sash windows updated to include the draft proofing system and low E glass glazed units. then the next best thing would be secondary glazing or thick curtains that will keep heat in but not nearly as much as properly made and fitted sash windows.

Various styles of sash windows

Most sash windows are made to measure, as with most properties in london they are unique and the windows should match the existing.

This said there are distinct types of sash windows

Georgian Era 1720 - 1840
Normally six over 6 panes traditionally with one sash fixed.
this would have meant 6 panes of glass in the top and bottom sashes.
these are now made with both sashes moving, and double glazed units with glazing bars placed on top.
here are some examples.

Victorian Era 1830 - 1910
traditionally 6 or 4 panes of glass used in designs with both sashes moving. As the cost of glass manufacture dropped the panes of glass got bigger. Both sashes operate in Victorian sash windows.
we supply these double glazed with glazing bars.
here are some examples.

Edwardian Era 1901 - 1919
Typically this has no glazing bars in the lower sash, to allow more light to pass into the room, this was the fashionable style of sash window in the Edwardian era. Having large panes of glass was expensive and a sign of afflence during that time.
both sashes do move in this design.
we supply these double glazed with glazing bars.
here are some examples.

All sash windows and frames are made to measure to match your existing design or meet your choice for a new build or rennovation project, call to discuss your design and build requirements.

Woodstock Joinery London

A sash window or hung sash window is made of one or more movable panels or "sashes" that form a frame to hold panes of glass, which are often separated from other panes (or "lights") by narrow muntins. Although any window with this style of glazing is technically "a sash", the term is used almost exclusively to refer to windows where the glazed panels are opened by sliding vertically, or horizontally in a style known as a "Yorkshire light", sliding sash, or sash and case (so called because the weights are concealed in a box case). The oldest surviving examples of sash windows were installed in England in the 1670^s.

Source : http://en.wikipedia.org/wiki/Sash_window