Average size of the US house building is growing again
The Minneapolis Star-Tribune published a story, "After years of downsizing, big houses make a comeback: Low interest rates, higher incomes and longer wish lists contribute to sprawling new single-family homes," about how the average size of houses is growing again, after having "shrunk" on average for a few years after the real estate crash of 2007.
Eric Klinenberg on the Trend of Living Alone," New York Times; "Eric Klinenberg on Going Solo," Smithsonian Magazine).
This has many implications for housing policy, (1) in terms of allowing the construction of smaller units on affordability grounds, (2) legalizing accessory dwelling units, (3) general opposition of residents to housing types different from what they are familiar and comfortable with, out of the belief that accommodating "different" people willing to live in smaller units can lead to a diminishment of the quality of the neighborhood, and (4) microunits, which are even smaller than what used to be considered "small" ("Micro-units help DC renters live to the max," Washington Post). Seattle has experienced a great deal of construction of microunits ("Seattle's micro-housing boom offers an affordable alternative," Seattle Times); "Are apodments ruining Seattle neighborhoods?," Seattle Magazine).
Another element is the teardown of smaller houses, generally on smaller lots, in favor of much larger houses on the same lot. Residents often oppose this because it changes the character of a neighborhood ("Teardowns: Tearing apart or building up the neighborhood," Washington Post)..
I do wonder about the municipal finance implications. Some could make the argument that bigger houses with fewer residents draw less in the way of city services than the same size building with multiple units with more residents, even if they are smaller households. It's an interesting question to research.
-- The Macro View on Micro Units, report, Urban Land Institute
The article has a diagram showing data for average house size in different areas of the country.