002Sash windows are supposed to originate in Holland. However the oldest written document in this issue dates back to 1669 and is from Britain: The famous British architect Sir Christoper Wren, orders Thomas Kinward (a carpenter in London) to place cords and pulleys to the sash windows in Queen’s drawing room. This refers to the traditional mechanism, which enables to stop the sash vertically at the desired position and to move it easily by hand. Modern mechanisms are in a way more developped versions of what Sir Christoper Wren mentioned at his time.

A modern mechanism, consisting of stainless steel springs placed in a pipe of 16-26 cm diameter is able to move a 45 kg sash simply by your fingers and to leave it at any position you like. Historical sash mechanisms, on the other hand, continue to draw attentions with many examples still working on period buildings from 19th and 18th centuries. The common practice in many countries is to conserve period buildings by controlling renovation works and therefore, replacement of historic windows must replicate the detailing of the originals. At urban JOINERY we manufacture sash windows with modern mechanisms for both contemporary and historic buildings.

Sash Windows With Counterweights:

Traditional Sash windows consisting of two sashes, which slide vertically in a frame, supported by cords that are balanced with metal weights are still manufactured by skilled joiners

003_engThe following sketch shows such a traditional balance system.

1. Pulleys
2. Metal weights.
3. Inside.
4. Outside
5. Space for metal weights.