Map of the U.S. showing the average size of new apartments in the 100 metro areas with the most high-density apartment units. In 2022, new apartments in southern U.S. cities were bigger than average, while apartments in the north and Pacific coast were smaller. Seattle had the smallest new apartments at 659 square feet, 26% smaller than the U.S. average of 887 square feet. Tallahassee, Florida had the biggest at 1,182 square feet, 33% bigger than average.