The one timber window that has never gone out of fashion is the traditional sliding sash, which is also known as the “Box sash window”. The sash is one of the most successful, long lasting and highest character of wooden windows. It has been designed into traditional buildings for centuries and is often an integral part of a building’s architecture.
After the introduction of upvc and aluminium windows, many local authorities ensured these windows could not be replaced with anything but an exact replica under conservation laws. Although this may have been an inconvenience to some homeowners and plenty of developers, the majority of people see the benefit of such a ruling. The only downside for certain areas is if the glass must be replaced as existing. This is due to the extra glazing bar width required for double glazed units, but sacrifices a large amount of heat insulation.
Besides the strong methods of construction, one of the main reasons sash windows are so long lasting is their simple opening mechanism, operated by a weight and cord system. Although the windows can now also be opened by spring balances, there is still no competing with the characteristic charm and simplicity of the weights and cords.
The modern box sash window of today has lost none of its original appeal. In fact, it’s improved greatly. You can now have high insulation double glazed units, smooth opening action, secure locking and reliable weather seals, and still retain all the character of your original frames.
The cost of replacing sliding sash windows can be a hurdle. They’re among the most expensive windows on the market. However, to remove them from a building and replace with a substitute or imitation may compromise the buildings character and subsequently its market value. In contrast, replacing as original will enhance a properties value and appeal to a prospective buyer.
The window market has developed a few imitations in recent years by either placing horns on the bottom of an outward opening sash, or a vertical slider in upvc. Although these may suffice at a glance or from distance, a closer inspection will quickly reveal the truth. No imitation or substitute window will ever be able to replace a real timber sash window.