The median size of a house built in 1973 was 1,525 square feet. Compare that to last year’s median – 2,453 square feet, and it's clear that American homes have made a 61 percent increase in four decades.
Using numbers from the U.S. Census Bureau’s statistics on the characteristics of newly built houses, Business Insider made 12 charts that show how much the average, the newly-built home has changed since the 1970s. The story notes the decline of wooden exterior walls and the increase in the percentage of homes with air conditioning.