Buying a $27 million mansion is supposed to feel like a victory lap. For Sam Altman, it turned into a legal fight over sewage, mold, and a pool that wouldn’t stop leaking.
The Sam Altman house in San Francisco’s Russian Hill neighborhood was meant to be the OpenAI CEO’s crown jewel property. Instead, it’s the subject of a lawsuit accusing the builder of selling him a “lemon,” and more recently, the target of alarming security incidents.
Here’s what happened, what the suit claims, and where things stand now.
Quick Facts
| Detail | Information |
|---|---|
| Owner | Sam Altman (via 950 Lombard LLC) |
| Address | Lombard Street, San Francisco |
| Neighborhood | Russian Hill |
| Original Architect | Willis Polk (1907) |
| Purchase Price | $27 million (March 2020) |
| Original Asking Price | $45 million (listed 2018) |
| Size | Approximately 9,500 sq. ft., 6 bedrooms, 7 bathrooms |
| Developer | Troon Pacific (via Eight Forty One LLC) |
| Developer’s CEO | Gregory “Greg” Malin |
| Lawsuit Filed | July 12, 2024, San Francisco Superior Court |
| Case Number | CGC-24-616350 |
| Estimated Repair Costs | Over $4 million |
| Case Status | Ongoing, designated complex litigation |
The Story Behind the Sam Altman House in Russian Hill
Even billionaires get burned buying at the top of the market, and this is a pretty good example of it.
Sam Altman is best known as CEO of OpenAI, the company behind ChatGPT. Before that, he ran Y Combinator, the startup accelerator behind Airbnb, Dropbox, and Stripe. That name recognition is part of why his real estate troubles didn’t stay quiet for long — a lawsuit involving almost anyone else’s contractor dispute wouldn’t have made national headlines.
Russian Hill has been one of San Francisco’s most desirable addresses for decades. Sweeping views of the bay, the Golden Gate Bridge, and downtown, plus a location just a block from Lombard Street’s famously crooked block, make it an easy sell for buyers with the budget to match. For Altman, the property offered privacy and status in equal measure.
The $27 Million Purchase
The house on Lombard Street first hit the market in 2018 at $45 million, making it the most expensive listing in San Francisco at the time. It sat unsold for two years.
Altman closed on the property in March 2020 for $27 million — an $18 million cut from the original ask, or roughly 40% off. The purchase went through an entity called 950 Lombard LLC, managed by his cousin Jennifer Serralta, and the address has since doubled as the registered business home for Apollo Projects, an early-stage investment firm that Altman runs with his brother, Jack Altman.
What he got for that money was a heavily reworked compound built on a home originally designed in 1907 by noted San Francisco architect Willis Polk. Developer Troon Pacific gutted and rebuilt much of the historic structure — so aggressively that the city later fined the company $400,000 for demolishing parts of the home without a permit. The finished product included a six-bedroom, seven-bathroom main house, a guest house, a wellness cottage, an infinity-edge pool, century-old olive trees, floor-to-ceiling glass doors designed for an indoor-outdoor living experience, an elevator, and a tunnel-style entrance that listings described as “Batcave”-like. On paper, it looked like a dream home. In practice, it’s been anything but.
What the Lawsuit Actually Claims
On July 12, 2024, 950 Lombard LLC filed suit in San Francisco Superior Court against Eight Forty One LLC, Troon Pacific, and CEO Greg Malin. The complaint accuses the developer of misrepresenting the home’s condition to close the sale quickly, then leaving the buyer to deal with the fallout.
“In sum, owner was misled into buying a $27,000,000 ‘lemon.'”
That line from the filing is the one that’s been quoted everywhere, and it sums up the whole case fairly well.
The Infinity Pool Turned Money Pit
The pool was supposed to be one of the property’s standout features — an infinity-edge design overlooking downtown San Francisco. Instead, the lawsuit says it was built with poor waterproofing design and installation, which led to leaks and eventually caused a major flood inside the mansion in August 2023 — bad enough that part of the ceiling reportedly gave way.
Fixing the pool and the water damage it caused makes up a large share of the repair bill Altman is now facing.
Raw Sewage and a Crushed Pipe
This is the part of the story that got the most attention, and it’s easy to see why. The suit alleges that an improperly connected bathroom sewer line was dumping raw sewage onto the ground outside the house.
On top of that, a crushed sewer pipe from the laundry system reportedly caused repeated backups and spillage inside the home. The filing also references contractor bags stuffed into sewer lines, allegedly by an unpaid subcontractor, and leaking irrigation lines on the rooftop garden. Between all of that, water and waste problems were coming from nearly every direction.
Mold in the Lower Level
Environmental testing cited in the lawsuit found widespread mold in the home’s lower level, tied directly back to the water intrusion from the pool and plumbing failures. Mold remediation in a home this size doesn’t come cheap, and it’s a big reason the repair estimate climbed past $4 million.
Who Is Troon Pacific, and Why Does This Keep Happening?
Troon Pacific built its name flipping high-end San Francisco homes, with Greg Malin as the company’s public face for years. This isn’t the first time the developer has ended up in court.
Just weeks before Altman’s suit was filed, an arbitrator ruled that Malin and Troon Pacific had engaged in fraudulent self-dealing on a separate group of luxury flips — properties on Union, Filbert, Pacific, and Carmel Streets — and ordered the company to pay back $48.1 million to the investors who’d funded them. Malin and the associated investment fund filed for bankruptcy in July 2023. That judgment involves a different set of investors and isn’t part of Altman’s case, but it points to a pattern worth knowing about.
Key takeaway: Altman isn’t the only person who says Troon Pacific overpromised and underdelivered. That context matters if you’re weighing whether a “lemon” claim like this one holds up in court.
What Altman Is Seeking
The lawsuit estimates repair costs at more than $4 million, covering the pool, plumbing, mold remediation, and related structural fixes, plus unspecified damages, interest, and attorneys’ fees. A city permit filed in February 2024 lists a separate $250,000 charge for exploratory demolition tied to investigating one of the leaks.
As of this writing, Troon Pacific and Malin haven’t issued a public response to the allegations. Court records show the case was designated complex litigation, with case management proceedings continuing into 2026 — a reminder that construction-defect suits like this one can drag on for years before reaching trial or settlement.
Expanding the Russian Hill Footprint
Owning a house that keeps flooding and smelling like sewage would wear anyone down, billionaire or not. It hasn’t slowed Altman’s appetite for Russian Hill real estate, though.
In January 2025, an LLC managed by Serralta purchased three adjoining properties next to Lombard Street for a reported $38.5 million, according to property records first reported by The Real Deal. Like the original mansion, the three dwellings were built in the early 1900s and had previously been combined into a single compound by their former owners in 1994. So even in the middle of a lawsuit over construction defects, Altman kept expanding his footprint on the same block.
Those purchases brought Altman’s total investment on that stretch of Lombard Street to roughly $65 million — a multi-parcel compound that his LLCs now control.
There’s a lighter side to life at the mansion, too. In a Time interview, Altman mentioned a coyote that had taken up residence on the property, saying it “moved into my house and scratches on the door outside.” His husband, Oliver Mulherin — the two married in 2024 — snapped a photo of the animal lounging on the outdoor furniture.
When the Property Became a Target
The construction lawsuit isn’t the only serious trouble the Lombard Street address has seen. In April 2025, the property became the site of two separate security incidents that drew national attention and underscored the hostility building toward figures in the artificial intelligence industry.
The Molotov Cocktail Attack
In the early hours of April 10, 2025, a man approached the gate of Altman’s Russian Hill home and hurled a Molotov cocktail at the building at approximately 3:45 a.m. Surveillance footage captured the attack. The firebomb bounced off the structure, and no one was harmed.
The suspect, 20-year-old Daniel Moreno-Gama of Spring, Texas, had allegedly traveled from the Houston area specifically to target Altman. Less than two hours after the attack on the mansion, Moreno-Gama appeared at OpenAI’s San Francisco headquarters, where he reportedly attempted to break in while carrying a jug of kerosene and a lighter. He told building security that he planned to burn the facility down and kill anyone inside, according to a federal criminal complaint.
When San Francisco police arrested Moreno-Gama at the scene, they found incendiary devices, kerosene, and a written manifesto condemning artificial intelligence. The document included a section titled “Your Last Warning” that named AI executives as targets, according to authorities. Online, Moreno-Gama had used the alias “Butlerian Jihadist” — a reference to the human uprising against thinking machines in Frank Herbert’s Dune — and had participated in public forums for anti-AI organizations, including PauseAI and Stop AI.
Federal prosecutors charged Moreno-Gama with attempted arson and attempted murder. His public defender characterized the case as “overcharged” and argued it stemmed from a mental health crisis rather than a deliberate act of terrorism, noting that Moreno-Gama had no prior criminal record. His parents released a statement saying their son had been “suffering recently from a mental illness crisis.”
U.S. Attorney Craig Missakian stated that if the evidence showed the attack was intended to change public policy, it would be treated as an act of domestic terrorism. The FBI issued a statement saying it “will not tolerate threats against our nation’s innovation leaders.”
The Drive-By Shooting
Two days after the Molotov incident, on April 12, San Francisco police arrested two people after shots were fired from a car outside Altman’s home. The pair was released from custody without charges, and the San Francisco district attorney’s office stated that further investigation was underway to determine whether charges would be filed.
Altman’s Response
Altman addressed both incidents in a blog post, calling for a de-escalation of the debate around artificial intelligence and sharing a rare photo of his family, including his infant daughter.
“Images have power, I hope,” he wrote. “Normally we try to be pretty private, but in this case I am sharing a photo in the hopes that it might dissuade the next person from throwing a Molotov cocktail at our house, no matter what they think about me.”
The incidents represent an escalation in targeted hostility toward AI industry figures, and they’ve added a layer of security concern to a property that was already dealing with significant construction-related headaches.
Altman’s Broader Real Estate Portfolio
The Russian Hill compound, even with its adjacent properties, represents only part of Sam Altman’s real estate holdings. Property records and reporting by Business Insider and the New York Times reveal a portfolio spanning California and Hawaii, with a combined value exceeding $120 million — all managed through a network of LLCs overseen by his cousin Jennifer Serralta.
The Hawaii Beachfront Estate
In July 2021, Altman quietly purchased a 12-bedroom oceanfront estate in Kailua-Kona on Hawaii’s Big Island for $43 million. The property sits next to a reconstruction of the temple of King Kamehameha I, the first ruler of the Kingdom of Hawaii, and includes a tennis court, swimming pool, and multiple guesthouses. Altman’s Sam Altman Qualified Opportunity Fund is registered to an adjacent address, and he has previously shared images of himself wakesurfing in the area.
Green Valley Ranch, Napa
Altman’s most pastoral holding is Green Valley Ranch, a sprawling 950-acre estate in Napa County purchased for $15.7 million in 2020 — well below its original asking price of $25.5 million. The ranch spans nine parcels and includes five distinct residences: a main ranch house, a terra guesthouse, a meadow house, a Palladian-inspired lake house, and a charming artist house. The surrounding land supports vineyards and a cattle operation.
The ranch had previously been owned communally by eight men for 42 years. One of them, Hollywood lighting designer Bob Dickinson, told the CT Post that the unnamed buyer had “a complete passion for the land.”
“It’s hard to explain how marvelous it is to live where there are still river otters on your property and oaks that are centuries old,” Dickinson said. “He gets it. He’s enthusiastic about it.”
According to the New York Times, which visited the ranch in 2023, the 25-year-old main home had been remodeled to “look both folksy and contemporary.” Altman, a vegetarian, and his husband Mulherin were raising beef cattle on the surrounding land, tended by farmhands who also managed the vineyards. The couple spends many of their weekends at the property.
Lessons for Luxury Buyers
What stands out here isn’t just the size of the numbers. It’s how easily a home that looks flawless in listing photos can hide serious problems that only surface after move-in — and how a high-profile address can attract dangers well beyond construction defects.
For anyone shopping in the ultra-luxury market, this case is a reminder to push hard on independent inspections and waterproofing reports before closing, no matter how polished the listing looks — and to check a developer’s litigation history, not just their portfolio. The broader lesson from Altman’s experience is that even after you buy, a property’s story doesn’t end at the closing table.
Final Thoughts
A $27 million price tag doesn’t guarantee a problem-free home, and Sam Altman’s Russian Hill mansion proves it. Between the sewage lines, the flooded pool, and the mold remediation, this “dream house” has become one of the more talked-about real estate disputes in San Francisco in recent memory — and that was before it became the site of a firebombing.
The Lombard Street property is only one piece of a much larger real estate picture that stretches from San Francisco’s hills to Hawaii’s coastline to Napa’s vineyards. Whichever way the lawsuit lands, it’s already shaping how buyers and agents talk about due diligence in the luxury market — and how much a listing photo can leave out.
