Sash windows are a common sight in period properties in the UK and are thought to date back to the 17th century when the Royal family had them installed in their properties, praising their elegant design and symmetrical appearance.

How sash windows work

Sash windows use ropes, pulleys and weights to ventilate rooms without letting in unacceptable amounts of cold air. Because hot air rises, you only need to open sash windows a little bit to begin drawing in fresh air at the bottom of the sash while pushing out hot air at the top.

Though the design remains little changed from its origins, companies such as //www.sashwindowpreservation.co.uk/services/sash-window-repair/ can perform a sash window repair, meaning that historically significant features need not be replaced when damaged.

Historical developments.

The earliest examples of sash windows in the UK can be seen at Whitehall Palace and Ham House.

In 1666, the Great Fire of London caused a change to building regulations, mandating that frames should be small and recessed to reduce their likelihood of catching fire.

In the 1800s, large-scale commercial glass manufacture enabled small panes to be replaced with fewer, larger windows, so when the glass tax and window tax were repealed in 1845 and 1851, respectively, windows became more desirable and affordable for the masses.

In 1894, the Building Act was updated to remove the requirement for windows to be flush with the external building facade, leading to a rise in the popularity of bay windows.

Nowadays, historic sash windows still exist, though many have been replaced by uPVC equivalents.