America’s oldest housing stock, city by city

What median year structure built actually is

Table B25035 publishes one number for a place: the year that divides its housing units into two equal halves, half built before it and half after.

The universe is all housing units, owned, rented, occupied and vacant. Median age of housing is the survey year minus that value, the Census convention this page uses: 2023 minus the median year built.

It is computed on a fixed ten-interval distribution running from “Built 2020 or later” down to “Built 1939 or earlier”, so it is interpolated rather than raw. Two consequences follow, and both matter more than the ranking.

First, the estimate carries a margin of error: one or two years at 90 percent confidence for every city here not at the floor. Small, but enough that a one-year gap between two cities is not a difference. Second, the floor, which has its own section below.

HyreRoof analysis: the median describes the middle and says nothing about the tails. A city with an old core and decades of new building around it can post a late-1980s median while holding tens of thousands of pre-war homes. Atlanta does.

So this study publishes the median, the pre-1940 share and the pre-1980 share for every city, because the three answer different questions.

The forty oldest of the hundred largest cities

The top of that chart is the industrial Northeast and Midwest: Buffalo, St. Louis, Rochester, Cleveland, Pittsburgh, Detroit, Baltimore, Philadelphia, Cincinnati, Milwaukee, Toledo. San Francisco and Boston are the coastal exceptions, with medians of 1945 and 1947.

The bottom is the Sun Belt and it is just as consistent: Irvine (2001), Henderson (2000), Cape Coral (1999), Chandler (1997), Raleigh (1996), Las Vegas and Charlotte and Durham (1994). In each, more than half the homes standing today were built after 1991.

HyreRoof analysis: do not read the spread as a league table of decay. Detroit’s median of 1947 and Irvine’s of 2001 both say when construction happened. The fifty-four years between them point to different roofing work, not to better or worse places.

Where the median lies to you

HyreRoof calculation: the two measures agree closely: the correlation between median year built and pre-1940 share across the hundred cities is r = −0.936. That is expected. The interesting part is where they disagree.

Atlanta ranks 82nd of 100 on median year built (1987) and 42nd on pre-1940 share (12.1 percent). Fort Worth ranks 90th on the median and 61st on the share; Durham 93rd and 68th.

These cities have an old core with a large amount of newer building around it, and the median sits in the newer stock because that is where most of the units are. Reading Atlanta as a young-housing city because its median is 1987 misses 31,231 pre-war units.

The error runs the other way too. Fort Lauderdale ranks 41st on median year built (1972) but 87th on pre-1940 share (1.6 percent); Anaheim 42nd and 83rd; Anchorage 65th and 91st. These places have a middle-aged stock with almost no pre-war tail.

HyreRoof analysis: for roofing questions the tail can matter more than the middle. Pre-war stock is where you can find board sheathing rather than panel decking, slate and clay tile rather than asphalt, and the accumulated layers HUD’s inspection guide warns about.

A single median cannot carry any of that, which is why the table above has three columns instead of one.

What an old housing stock does mean for roofing

Since the answer to “does an old city mean old roofs” is no, it helps to be precise about what an old city does mean. Four things, all from the construction rather than the covering’s age.

The material mix is different. HUD’s inspection guide describes slate, clay tile and asbestos cement shingles as “extremely durable and, if of high quality and properly maintained, may last the life of the structure,” and metal as lasting “50 years or more if properly painted or otherwise maintained.”

Where a pre-war stock has more of these than a 1990s stock, those roofs do not sit on a twenty-year cycle at all.

HyreRoof analysis: that cuts against the intuition the ranking invites. Some of the oldest housing can carry some of the least often replaced roofs.

The layer count is different. The same guide states that “no more than two layers of asphalt shingles should normally be in place at any one time”, and puts the service life of a second layer laid over a first at about fifteen years against about twenty for the first.

Older housing has had more opportunities to accumulate layers, and a house at the two-layer limit faces a tear-off rather than a roof-over on its next job: a different scope and a different price.

The deck can be different. A pre-war roof may be sheathed in boards rather than panels, and a wood shingle roof of the period may sit on spaced sheathing. Neither is a defect. Both change what a tear-off finds and what the new covering is fastened to.

The regulator can be different. Some cities run their own licensing, permitting and inspection on top of, or in place of, what the state does.

Which regime you are in changes what a credential proves; we have set out the six ways American states regulate roofing and why the published counts of “licensed states” disagree with each other.

Method

Source. Every housing figure was read from the Census Bureau’s ACS 2023 5-year table-based Summary File: the pipe-delimited releases acsdt5y2023-b25035.dat, acsdt5y2023-b25034.dat, acsdt5y2023-b25036.dat and acsdt5y2023-b25037.dat, joined to the geography file Geos20235YR.txt on GEO_ID. Nothing was taken from a secondary summary, a real-estate listing site or another “oldest cities” article.

Universe. Summary level 160, incorporated places, in the fifty states and the District of Columbia and Puerto Rico.

Census-designated places, zonas urbanas and comunidades were excluded because they are statistical areas rather than municipal governments; Urban Honolulu, Arlington in Virginia, and Paradise, Spring Valley, Enterprise and Sunrise Manor in Nevada would otherwise have entered the hundred on size.

Selection. The hundred places with the most total housing units (B25034_001E), which is the only variable used to select. That threshold is 95,116 housing units.

Selecting on housing units rather than population is deliberate: the question is about buildings, and a place with many small households would otherwise be under-weighted relative to the roofs it contains.

Ranking. Ascending on B25035_001E, which is the single measured variable. Where two cities share a median year the tie is broken for display by the pre-1940 share. No composite score is used anywhere on this page. A twenty-factor “oldest housing” index would be unfalsifiable and this desk does not build them.

HyreRoof calculation, median age. Median age of housing = 2023 minus median year structure built, which is the arithmetic the Census Bureau’s own subject definitions describe. For the three floor cities the result is written as “85+ yr” because 1938 is a sentinel and the true median is 1939 or earlier.

HyreRoof calculation, cohort shares. Pre-1940 share = B25034_011E ÷ B25034_001E. Pre-1980 share = (B25034_007E + B25034_008E + B25034_009E + B25034_010E + B25034_011E) ÷ B25034_001E. Both are ratios of estimates from the same table; their margins of error are not propagated here and the Limitations section says so.

HyreRoof calculation: the correlation. Pearson r between median year built and pre-1940 share across the hundred cities is −0.936, computed on the published values including the three at the floor. Including them biases the coefficient toward zero, because their true medians are 1938 or earlier, not 1938; the real relationship is at least this strong.

Verification of the sentinels. The 1938 floor and the 2021 ceiling were not assumed from documentation. Across all 543,542 rows of the B25035 release, 34,417 carry the value 1938 and 84 carry 2021, and exactly 34,501 rows carry the −333333333 margin-of-error annotation. The counts match to the row.