Rapid Development of Window Designs in the 17th century
This is where the history gets fuzzy and I’m not doing a PHD thesis on this so I’ll try and keep it brief. If someone else wants to fill in blanks please get in touch.
The easily available history seems to jump from leaded casements to timber double hung sliding sashes in the likes of Chatsworth house alterations 1676 – 1690.
Early Sliding Sash Windows at Chatsworth House
That’s a big jump! It will have actually come in little steps over the preceding years. Here are some factors that will have come in to this radical modernisation of the popular technology.
1. The size of glass panes which could be economically manufactured was increasing. Gone where the days when lots of 4 inch or smallerpanes had to pieced together with lead.
2. At some point around this time putty was invented. This seems to be a neglected factor in the history although I’ve come across dates around 1737 -1745. Putty or something similar will have existed previously to enable glass to be framed in timber.
3. Windows had tended to be more of a horizontal proportion in smaller buildings. Think of the low ceiling heights. At some time, larger panes with timber glazing bars started replacing the old style leaded windows especially on “new builds”. Rather than having a hinged opening casement it was easier/cheaper to have a carpenter make the opening sliding horizontally. I dare say the blacksmiths lost a fair bit of work. This window type became know as the Yorkshire window, I’m not sure how the Lancastrians felt about that. (Pure unsubstantiated conjecture on my part)
"Yorkshire" Horizantally Sliding Sash Window
4. New styles of architecture were coming in from the continent, Neo classical and Baroque. This style change demanded a more vertical window proportion. The French seem to have come up with timber constructed windows with a bottom sash that slid up and was held in place with pegs.
5. Society was in flux. The English Civil War, Merchants became prosperous, populations in towns and cities grew at a rapid rate. Demand for houses with glazed windows was soaring.
The development of the continental style, to make it really practical, seems to have fallen to a couple of Brits. Thomas Kinward, master joiner in the Office of the King’s Works, and Robert Hooke, fellow of the Royal Society. A simple system of pulley cords and counterweight held the sash in the open position. Originally just the bottom sash but later the top sash as well. Allowing the frailest of servents to open and close massive windows.
The double hung sliding sash window then took the nation and empire by storm.
Any comments or suggestion you might have please let me know here.