Mapping the Average House Age by County

Last year I moved into a city which had much older housing stock than other cities that I had lived in before. I was under-prepared for the housing market here, because I had not researched the factors that you should look into for older homes which vary a lot depending on the era that they were built in.  I created this interactive mobile friendly map to visually help show the differences in regions and counties.

Tips: There are plus [+] and minus [-] buttons to zoom in or out of the map.  You can also drag to move around the map. If you click or hover over a county, a tool tip will appear with that county’s break down of housing age. If you’re on mobile, pinch to zoom works as well.

Housing Stock Age Map

Older Housing
Newer Housing

Average Home Built in
Average Home Age

Homes Built by Decade
Built 2010 or Later
Built 2000 thru 2009
Built 1990 thru 1999
Built 1980 thru 1989
Built 1970 thru 1979
Built 1960 thru 1969
Built 1950 thru 1959
Built 1940 thru 1949
Built 1939 and Earlier

Counties with the oldest housing

County Avg Build Date Age (Years)
Webster County, Nebraska 1926 91
Suffolk County, Massachusetts 1928 88
Franklin County, Nebraska 1929 87
Greeley County, Nebraska 1932 85
Jewell County, Kansas 1932 85
Richardson County, Nebraska 1933 83
Stark County, Illinois 1934 83
Keokuk County, Iowa 1935 82
Pawnee County, Nebraska 1936 81
St. Louis city, Missouri 1936 80

Counties with the Newest Housing

County Avg Build Date Age (Years)
Sumter County, Florida 1997 19
Collin County, Texas 1997 20
Rockwall County, Texas 1997 20
Forsyth County, Georgia 1996 21
Williamson County, Texas 1995 21
Flagler County, Florida 1995 22
Henry County, Georgia 1994 22
Hancock County, Mississippi 1994 23
Kendall County, Illinois 1994 23
Long County, Georgia 1993 24


Interesting things I saw

  • The gold areas (older homes) of the Midwest and Northeast are in the Rust Belt, which makes sense.
  • The South-East, Texas, and Western states have seen a lot of new housing go up in the last few decades.
  • The large gold areas in the Great Plains correspond to the depopulation of the rural areas in the Great Plains because of urbanization, the Dust bowl, and the Great Depression.  I had to look it up, because I thought I had made an error.

Post a comment if you found something else from the map!

Notes: the original data is from the 2014 5 Year Data Profile American Community Survey by the US Census. The Average Home Built-in metric was calculated using the data from the ACS and slightly interpolated especially for the 1939 and earlier bucket of data, because it represents such a large period of time. Also I have to give a big thanks to Nathan Yau of Flowing Data for his great tutorials.

2 thoughts on “Mapping the Average House Age by County”

  1. Hi! Thank you so much for building this map. I’m actually researching solar energy in Illinois and would love to have the dataset you have for average age of house in Illinois per COUNTY if possible. Thank you – please let me know if this is possible. I really appreciate it. It would make a great difference to my senior thesis!

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