The fragment on the left is taken from Robert J Shiller, an economist at Yale University. The data comes originally from the United States census, but the actual source is not cited. This is an area that I will continue work on, because it is important, when considering the space in the home dedicated to a workshop.
(Source: Robert J Shiller, "Long-Term Perspectives on the Current Boom in Home Prices", Economist's Voice March 2006, page 6.)
Will cover this in greater detail, but note briefly the post-WW II housing boom resulted in the "attached two-car garage", a spot homeowners soon discovered was perfect for a homeworkshop.