In the Regency home, the window was a more important feature than it had ever been before. From 1790 to 1830, long, tall windows were the fashion. Older properties could be modernised by ‘dropping’ the window sills and installing new sashes.
A sash window consists of a pair of glazed panels, or ‘sashes’, which slide, usually vertically, in a case or frame. The window frames were usually made of deal (pine), painted white or grained. Oak was occasionally used for the most prestigious houses.
Weights, housed in the window frame, balance one or both of the sashes, to which they are attached by cords passing over pulleys fixed in the case. The mechanism relies on the weight of the sash panel and its counter-weights being almost the same, with the weights a little heavier than the upper sash, and a little lighter than the lower sash, for efficient closing.
Above: Sash window pattern c1836.
When the homes of Brunswick Town were built in the 1820s and 30s all the sash windows were in Georgian pattern with glazing bars, as is seen on just a few of the houses today.
'Original windows are removed countrywide at the rate of one per minute.’
-The English Heritage
If you are interested in further reading on this topic, these links will provide you with more information: