Apartment sizes are getting smaller and smaller in the US. Research by RCLCO Real Estate Advisors tracked trends in apartment sizes and found that apartments today are 100 square feet smaller than those built in the 2000s. They fell from an average of 1,031 square feet for homes built between 2000 and 2009 to 931 square feet for homes built between 2015 and 2019. That is a 9.7% reduction in the average home size.