In a previous In Your Opinion we gave you the reason for the small hole in the windows of airplanes. Today we focus on the thickness of the glazing.
The outer pane of an aircraft window is 0.47 in ( 12 mm ) thick and the inner pane is 0.16 in ( 4 mm ) thick. They are separated by a 0.23 in ( 6 mm ) air chamber, making a total thickness of 0.87 in ( 22 mm ) for the entire window, which may seem thin, but the outer pane is thicker than the plane's fuselage. These thicknesses are calculated using the minimum safety limits allowable, in function of the resistance of the materials used, in order to reduce the aircraft’s weight to a minimum.
By comparison, the standard double glazed window of a house has two glass panes, each with a thickness of 0.16 in ( 4 mm ) and an air chamber of also 0.23 in ( 6 mm ) being 0.55 in ( 14 mm ) in total. If you decide to increase the sound or noise insulation in your home, you need to increase the thickness of the inner pane of the window ( so both panes do not vibrate at the same frequency ) unlike an aircraft window which is thicker on the outside due to the pressure exerted over the entire fuselage.