BERKELEY -- Judging by the age of their housing stock, Berkeley, San Francisco and Oakland are the oldest cities west of the Mississippi River region and among the oldest in the nation.

More than half of Berkeley and San Francisco households, and nearly 42 percent of Oakland households, are in residences built before World War II, according to statistics released by the U.S. Census Bureau. Alameda is not far behind, with nearly 34 percent of the island city's housing built before the war.

The enormous stock of vintage housing -- from stately Victorians in West Oakland to whimsical Storybook houses and dark-wooded Craftsman bungalows -- is a source of pride for Bay Area residents dedicated to keeping the buildings preserved.

"We feel that Berkeley's pretty special because of its historic architecture," said Anthony Bruce of the Berkeley Architectural Heritage Foundation. "A lot of people come here to see the university, but other people come here because they know there's good residential architecture to look at."

Just 23 cities nationwide with more than 65,000 people, including Berkeley and San Francisco, share the distinction of having more than half of their housing units built before 1939. Most are in New England, and the others are in New York, Pennsylvania and the Midwest.

Bruce was not surprised by the figures showing about 51 percent of Berkeley's houses and apartment units were built before 1939. He sees them every day. But he was surprised that the Bay Area cities had a proportionally higher stock of older housing than many East Coast and Midwestern cities that were founded and developed much earlier -- places such as Philadelphia, New York City, Baltimore, Chicago, Hartford, Conn., Savannah, Ga., and Washington, D.C.

Of big cities with more than 500,000 people, only Boston, with 58 percent, had a higher rate of pre-1939 housing than San Francisco.

And while Boston had a few centuries to develop, the housing landscape of today's Berkeley and Oakland is largely the result of a few decades of rapid growth. Some of it was spurred by San Franciscans moving out of their city after the 1906 earthquake.

"There was a big building boom in the early 1900s and again in the 1920s," Bruce said of Berkeley.

The Bay Area cities are unique in California, where the overall proportion of pre-World War II housing is only 9.8 percent.

One reason for the high rates of old housing in Berkeley and San Francisco: By the time the postwar housing boom arrived, the cities were almost out of space to expand. San Francisco, bounded by water on three sides, grew until it hit the ocean. Berkeley grew steadily in the 1940s and 1950s and expanded into the hills.

Berkeley's architectural heritage is a point of pride in the city but not a politically neutral topic. Preservationists have long battled with pro-growth forces over what buildings should be saved and how many new homes can be built. In the November election, Berkeley voters will decide on Measure R, a philosophical blueprint for concentrating more new housing and jobs near downtown transit. Proponents promise it will protect historic resources, but opponents, including Bruce's architectural heritage society, fear it will weaken Berkeley's landmark protection law and lead to the demolition of older buildings, including those used for lower-cost housing.

Is older better? Having so many vintage homes can have disadvantages, especially if they are not maintained or, in earthquake country such as the Bay Area, if they do not meet modern seismic standards. But they can also be an attraction, Bruce said.

"There's certainly some character to them that maybe you wouldn't find today," Bruce said. "There's good buildings from every era, but I particularly like early 20th century, so I'm happy to be in this town."

The survey
Released last week, the 2009 statistics from the U.S. Census Bureau's American Community Survey are estimates from a survey of about 3 million American households. They are also the best national housing statistics available because the full, once-a-decade census no longer asks details about every person's home.
Because they are estimates based on a sample of the population, there is a margin of error that makes the survey less reliable for smaller cities. For instance, the proportion of Berkeley housing built before 1939 could actually range from 47.7 to 54.5 percent.