Given that single-family homes have been generally getting larger, it may be tempting to assume that the lots they’re sitting on are getting larger as well. However, according to the Census Bureau’s Characteristics of New Single-Family Houses Sold, the opposite is closer to the truth. The median lot size of a new single-family detached home sold was an even 10,000 square feet from 1992 through 1995, then drifted downward until it reached 8,833 square feet in 2004.
After 2004, median lot size bounced back up to over 9,000 square feet for a few years before resuming a downward trend. By 2012, the median lot size of a new single-family detached home sold had fallen to 8,687 square feet, and in 2013 is was still only 8,720–the smallest two numbers in the historical Census series.
An acre is 43,560 square feet, so the above median lot size for 2013 is almost exactly one-fifth of an acre. Not everyone has a good sense of how big an acre is. To help visualize it, consider that, between the goal lines, a football field covers just about 1.1 acre. This means that, if you placed a median-sized lot for a single-family detached home sold that filled the width of the field (160 feet) on the goal line, it would reach just past the 18 yard line. And if you laid 5 of them side by side they would extend nearly to the opposite 9 yard line–leaving space for almost exactly half another median-sized lot before reaching the other end zone.
By definition, the single-family detached homes sold discussed above exclude “custom” homes built on the home owner’s land, either with the owner hiring a builder or serving as the general contractor him or herself. They also exclude single-family attached homes–that is, homes built side-by-side in a townhouse arrangement.
Lot sizes for custom homes tend to be larger. The median lot size for custom single-family detached homes started was exactly one acre (suggesting some rounding in the data) every year from 1999 through 2012. In 2013, it dropped 10 percent to 39,204 square feet. Custom homes don’t involve the work of a professional land developer subdividing a property, and some people may not think of them as sitting on lots in the conventional sense. Currently, custom homes account for a little under a quarter of the single-family market.
On the other hand, townhouses–currently a little over 10 percent of the single-family market–tend to have smaller lots. In 2013, median lot size for single-family attached homes sold was 2,984 square feet. Median lot size for all single-family homes sold in 2013–attached and detached combined–was 8,596 square feet.
So, although it becomes a little harder to visualize, if you had a normal mix of detached and attached single-family homes built for sale with the median lot size, about 5.6 of them would fit on a standard American football field between the goal lines, compared to almost exactly 5 and a half for single-family detached only.