Single Glazing was done many years ago, and still has its uses today.  An overwhelming majority of our window replacements are replacing single glazed windows with double glazed windows.

Double glazing is the glazing process in which a window is formed by two panes of glass with a space between the panes. This space can be a few millimeters think to several millimeters thick.  When cold temperatures occur, the air is trapped between the panes of glass and forms a layer of insulation.   You must use drying agents before sealing the window to ensure no moisture is present inside the finished glass unit.  Doing this incorrectly can cause mold or mildew and is another reason we get called to replace windows.  Someone attempted to do their own window installation and skipped this vital step.  This makes the whole work needed to be done again.

Single glazing windows still are used today for areas where insulation is not a factor.  Using single glazing windows reduces the cost of the windows.  If heating costs are a concern in new construction, you should always go with double glazed windows.