Window Replacement Info - Single or Double Sash

If you are thinking about replacing your windows, no doubt you have taken the important factors of price, style and durability into consideration, and come up with the best window to fit your home and budget. One thing you might not have considered is whether to use single or double glazed windows. This article explains the differences between the two types so you can make a more informed decision.

Single-Glazed Windows

Single-glazed wood replacement windows have been standard since the 18th century, especially in the New England area, where some manufacturers refer to them as 'Boston Pattern' windows. Single glazed windows can still be purchased as stock items and come in several sizes. Although single glazed windows aren't thought to be as energy efficient as double glazed windows, the addition of an energy or a good quality storm window can make a single-glazed window's energy efficiency the same as a double-glazed window.

Single-glazed replacement sashes are the least expensive wood replacement alternatives. These windows are often easy to repair, as damaged parts don't necessarily affect the whole. The cost of a brand new single-glazed wood sash together with a good quality storm window is about the same as the cost of a mid-range double-glazed replacement window.

Double-Glazed Windows

Double-glazed windows are the height of window technology, as they come with their own insulation. They have two layers of glass to create energy efficiency. Special glass treatments or gases can even be added between the layers to enhance the window's energy efficiency even further. One problem with double glazed windows is the strange optical effects that can occur between the panels, especially if there are glass treatments or gasses on the inside. Also, because a double-glazed window is heavier, it can be difficult to make these window look historic.

Recent advances in adhesive technology have led to the development of what are called 'simulated-divided light' sashes, which allow a the look of an historic window better for older houses trying to preserve their old-fashioned charm. Double-glazed windows in both true-divided light and simulated-divided light configurations are available from many manufacturers, but are generally more expensive than single-glazed windows. Typically, double-glazed windows have a limited life averaging 15 years.