Mark Zuckerberg says he doesn't have a Hawaiian doomsday bunker, just a 'little shelter.' It's bigger than most houses.

• Mark Zuckerberg is building a 1,400-acre compound in Kauai, Hawaii, with a vast basement.
• Plans for the compound show an underground structure nearly double the size of the average US house.
• In an interview with Bloomberg, Zuckerberg said it was only a "little shelter" for hurricanes and the like.

Mark Zuckerberg said the 4,500-square-foot underground structure in his Hawaii compound is just a "little shelter."

The description was in answer to the question of whether he is building some kind of armageddon shelter as part of his 1,400-acre property on the island of Kauai.

In a video with Bloomberg's "The Circuit" released on December 19, Zuckerberg effectively said the project was nothing to write home about.

Bloomberg's reporter, Emily Chang, asked if Zuckerberg was entering his "billionaire era" with the Hawaiian home.

(Business Insider in April calculated Zuckerberg's property holdings were worth about $200 million, spanning compounds in Palo Alto, Lake Tahoe and Hawaii.)

"The Kauai thing is really fun," Zuck responded. "We're doing ranching down there," he added, saying he was excited about creating "the highest quality of beef in the world."

In the video, the reporter asks Zuckerberg about the ranch's bunker, joking that he knows something we don't. Zuck responded: "No, I think that's just like a little shelter. It's like a basement."

He added later: "There's just a bunch of storage space and like, I don't know, whatever you want to call it: a hurricane shelter or whatever."

The little shelter, though, is fairly big.

Both Wired and local news outlet Hawaii News Now obtained planning documents showing an underground space spanning some 4,500 square feet.

That's close to double the size of the average US family home. Per census data, in Q2 2024 the medium new single-family home came it at 2,161 square feet.

Wired reported the plans for Zuckerberg's shelter, accessed via a tunnel, included a living space, mechanical room and escape hatch.

A local Hawaii realtor, Tom Tezak, told HNN that shelters were a rarity in Hawaii, and that he'd never seen one so large.

Zuckerberg told Bloomberg in response to media interest in the compound: "I think it got blown out of proportion as if the whole ranch was some kind of doomsday bunker, which is just not true."