829 Folsom, the 69-unit 2010 building beside the Yerba Buena Lofts: two one-bedrooms closed this year at $575,000 and $600,000, $830 a foot, in a building that sold at $1,369 in 2021

829 Folsom's two sales this year are both one-bedrooms under $600,000, in a building whose record peaked at $1,369 a foot five years ago. Two condominiums closed between January 1 and October 15, 2026, against two in the same window of 2025; $1,175,000 of volume against $1,268,000. The median sale is $587,500 and the median price per square foot is $830, against $781 last year, $916 across the four sales of 2022, the most in any year, and $1,369 on the $1,265,000 sale of 2021, the building's high.

#404, a 700-square-foot one-bedroom, transferred at $575,000 on August 19 with no listing, $821 a foot. #202, a 716-square-foot one-bedroom, closed at $600,000 on October 12 after 17 days, $838 a foot. Neither went inside two weeks. No unit that closed in 2026 has a prior recorded sale on this site, so there is no paired-resale table. Dues run $1,112 a month on an 837-square-foot one-bedroom, #200, which sold at $470,000 after listing in May 2025, and #408, a 486-square-foot studio, is listed at $445,000 with an open house on October 17 (Sereno, #200; RubyHome).

The building was marketed in December 2007 as 69 condominiums coming in 2008, with studios from about $550,000, and opened in 2010 after mechanics' liens were released in late 2009: nine floors of studios to three-bedrooms from 486 to 1,462 square feet by developer FORMA SF, with a roof deck, clubhouse, conference room and 24-hour door staff; the building record on this site lists 24 units under the name Museum Plaza, which none of the listing records use (SocketSite; RubyHome).

2026 so far, against the same window in 2025

Closings at Museum Plaza between January 1 and October 15, 2026, set against January 1 to October 15, 2025. Days on market is median days from listing to contract on MLS-listed sales; "under 15 days" counts how many of those went into contract inside two weeks.

Year by year

Every recorded closing at Museum Plaza since May 2010, by calendar year. 2026 runs through October 15, 2026. Days on market is available for MLS-listed sales from 2020 onward.

No year in the building's record holds five or more closings. 2026 year to date stands at $830 a square foot.

By bedroom count, 2025 against 2026

Every closing in 2026

All 2 closings through October 15, 2026, highest price first. Square footage and days on market are as recorded on the MLS; county-recorded transfers that never listed show no days.

Folsom, between Fourth and Fifth

Next door is Stanley Saitowitz's Yerba Buena Lofts, 200 lofts at 855 Folsom running through to Shipley, and Yerba Buena Gardens, SFMOMA and Moscone are a block north (Saitowitz; Sereno). Yerba Buena Lane and Jessie Square became an Entertainment Zone on May 16, 2025, allowing to-go drinks at outdoor events (CBS Bay Area).

The nearest AI office is Harvey's roughly 150,000 square feet at 201 Third, three blocks northeast, and Anthropic's Howard Street buildings begin two blocks beyond that (SF Standard).

The timetable that every South of Market building now sits inside is the public-offering calendar. Anthropic filed a confidential draft registration with the SEC on June 1, 2026, a week after a funding round that set its valuation at $965 billion (TechCrunch). As of this week the Standard reports the Anthropic listing has been pushed to November, after the midterms, that OpenAI's has moved to 2027, and that Anthropic is weighing a lockup longer than the usual six months (SF Standard). The same piece carries a Redfin estimate that current and former OpenAI and Anthropic employees could in theory buy close to a third of the metro area's homes with their proceeds, and the counter-argument from UC Berkeley's Enrico Moretti and the Bay Area Council's Jeff Bellisario that the money is concentrated in fewer hands than past booms and that these firms create fewer jobs per dollar because so much goes to data centers rather than headcount. The record in this report ends on October 15. None of it reflects a single share that has been sold.

Two citywide facts frame every building figure here. First, the office recovery is lopsided: CBRE put Q3 2026 vacancy at 27.7 percent citywide, down 6.6 points in a year, but Avison Young splits that into roughly 12 percent for Class A and north of 31 percent for Class B, and a Presidio Bay executive told Bisnow the headline number is misleading for that reason (Bisnow). Second, the condo market is still digging out: the Chronicle's May analysis found that only eight Bay Area ZIP codes showed inflation-adjusted condo gains over the year, all of them in San Francisco, and that Noe Valley's typical condo remained close to $400,000 below its 2019 level in real terms (SF Chronicle).

How this was counted

Two records feed this review. The MLS layer is one row per listing and carries days on market and square footage. The county layer reaches back further and catches transfers that never listed, but records the same closing once per data source, so the two were merged on unit, date and price and each closing kept once. Below-market-rate units and transfers under $300,000 are listed but excluded from every median. "Same window" means January 1 to October 15 of each year. Nothing here is a valuation of any unit, and nothing here is advice.

Tim McMullen · CA DRE #02016832
[email protected] · (415) 691-9272