The Bay Area has long had a reputation for being notoriously expensive, especially when it comes to the housing market. A new report from real estate data provider PropertyShark shows that the Bay Area continues to live up to that exclusive status.
According to its 2021 list of the top 100 most expensive zip codes in the country, 72% were concentrated in California, with 36 ZIP codes in the Bay Area’s nine counties appearing on the list. PropertyShark list included 127 ZIP codes, but for our analysis we cut the list down to just the first 100 zip codes.
The majority of the Bay Area zip codes are in the peninsula and South Bay, with 13 zip codes in Santa Clara County and nine in San Mateo County. For the fifth year in a row, Atherton in San Mateo County topped the list with a staggering median home sale price of $7.5 million. Last year, Atherton’s median home sale price was $7 million.
PropertyShark analyzes national home sales registered with county recorders. For the rankings, the company looked at the median home sale prices of transactions from Jan. 1 through Oct. 22, which includes the sale of single- and two-family homes, condos and co-ops.
The list only includes ZIP codes with a minimum of twenty transactions taken into account, and out of the Bay Area’s ZIP codes that appeared in the rankings, only three had fewer than 100 sales.
Eliza Theiss, the author of the study, said the “cost and exclusivity” of living in the Bay Area continues to soar, with 2021 prices increasing at an even sharper rate than in 2020.
“It’s more of the same trends we’ve been seeing over the past years, but 2021 further accentuated some factors such as increased price growth, especially in its priciest communities like Atherton,” she wrote in an email.
She said Atherton has “long been a favorite of ultra-high-income tech and business executives,” and as the town’s profile rose across the state and then nationally, it continues to attract interest from high profile buyers, “which in turn further raises prices and the community’s profile – creating a feedback loop of increased prices.”
Boston’s 02199 came in second place of the national rankings with a median sale price of $5.5 million. Also in the top 10 are ZIP codes in the Hamptons, Miami Beach and Beverly Hills, including two other Bay Area ZIP codes: 94957, located in the town of Ross in Marin County, with a median home sale price of $4.6 million, and 94022 in Los Altos, with a $4.1 million median home sale price.
Marin County had five ZIP codes in the top 100, including 94970 in Stinson Beach, with a median home sale price of $3.5 million.
Both San Francisco and Contra Costa County counted four zip codes in the top 100. The priciest ZIP code in San Francisco is 94123 – ranked 50th and dropped 10 spots from last year – which includes the Marina District and Cow Hollow. The median home sale price was $2.3 million.
San Francisco’s ZIP codes all appeared in the bottom half of the rankings. Theiss said interest in buying in San Francisco hasn’t gone down, even though there were fewer sales this year than in 2020.
“That was more the influence of further tightening inventories,” she said. “San Francisco’s ZIP codes ranking mostly in the bottom half isn’t a trend that is new to this year, but more the result of the city overall being far pricier than other locations, as opposed to locations that may rank with only one or two zips that represent only select neighborhoods favored by the area’s most wealthy individuals.”
She added that San Francisco still can’t compare to ultra-pricey locale such as Atherton or the Hamptons, and that many other California communities experienced a greater increase in their median sale prices than the city.
In Contra Costa County, 94528 or Diablo, a tiny Census-designated community northeast of Danville, tops the rankings with a median home sale price of $3.1 million. The only Alameda County ZIP code in the top 100 was in Berkeley, encompassing the Claremont and Elmwood neighborhoods.
Out of the complete list of 127 ZIP codes, Theiss said only six Bay Area zip codes had year-over-year price drops, and most were only a decline of 1% to 4%. Greenbrae in Marin County had the biggest decrease of 12%, down from a median home sale price of $2.1 million in 2020 to $1.85 million in 2021. St. Helena in Napa County debuted for the first time on the complete list with a median home sale price of $1.65 million.
Kellie Hwang is a San Francisco Chronicle staff writer. Email: kellie.hwang@sfchronicle.com Twitter: @KellieHwang