Window weights are common on double sash windows.
Window weights are lead weights that counteract the weight of a window frame, the moving part of the window, in older homes. They are common in double windows, in which the two leaves move on independent rails; the upper one can be lowered and the lower one raised, allowing a circular flow of air, the hot air coming out the top and the cooler air coming out the bottom. Since older windows are made of heavy materials, lifting them can be difficult, and without a counterweight, the frame can break, which can cause the glass to break. The solution is a polyester top of the window frame, with a cord attached to the frame, and within the window frame, window weights that are exactly or nearly equal to the weight of the frame. There are two window weights per sash, one on each side of the window.
The ‘frame cord’ is the cord that connects the window frame to the window weights. Over time, these strings can wear out and sometimes break, reducing the weight of the window. Because weight cavities, also called window weight wells, in the window frame sometimes run the full height of the house, window weights can drop from the second story to the ground floor.
Weighted windows are difficult to open if only one of the two window weights is in place, so if you have a broken sash cord and dropped a weight, you need to replace the cable and weight. Unless your home was built with small access panels that open to the weight bins, you will need to access the weight bins by removing part of the window frame. You can buy new window counterweights and framing strings at online home improvement stores.
If you’re renovating an older home with double glazing whose weight has sunk to the bottom a long time ago, it can be tempting to put off replacing window weights for later, holding the windows open with a stick or other obstruction. However, unbalanced windows can be very dangerous, especially if you have small children. It is recommended that you do not open the windows until you have replaced the window weights.
