Well, at the most basic level, they are windows that have movable glazed panels. The panels are called sashes and there are normally 2 sashes per window. There is a top sash (which is normally in front) and a bottom sash (which is normally behind) Most commonly, the sashes slide vertically, and both can be opened at the same time to create an airflow. There are sash windows that open horizontally which are known as Yorkshire sash windows (we haven’t actually ran across any down in Gloucestershire yet. If you have some that need a service, please get in touch here.
Each sash has a frame which holds panes of glass. They can be single panes, which fill the sash frame, or multi-panes. In which case there is more than one pane inside the frame which are separated by glazing bars.
The sashes sit inside a box frame. This is a frame which has hollow sections on either side. Inside these sections sit the sash cord, the weights and the pully. The sash cord connects the weight to the sash. The weights are commonly made of steel or lead. The weight inside the box needs to equal the weight of the sash to which it is attached. This is what makes the window stay where you put it.
That pretty much sums up the basics of the windows. As with most things there are lots of accessories that can be added to make the window more energy efficient (draught-proofing brush pile for example) , easier to use (finger lifts) or more secure (sash stops and locking fasteners come to mind).
Of course the window will work without these accessories. However we believe that the above accessories are beneficial to keeping your home secure and draught -free, and that’s why they are included as part of our draught-proofing service.
Written by Sam Causon, Renosash.