In the 70s, it was around 1600 http://www.aei.org/publication/todays-new-homes-are-1000-square-feet-larger-than-in-1973-and-the-living-space-per-person-has-dou

In the 70s, it was around 1600 http://www.aei.org/publication/todays-new-homes-are-1000-square-feet-larger-than-in-1973-and-the-living-space-per-person-has-doubled-over-last-40-years/ http://www.aei.org/publication/todays-new-homes-are-1000-squ...