$100 million De Guigné estate comes with quite a contingency

Here's one of the more unusual home sale restrictions we've come across -- and we aren't referring to the estate's whopping $100 million price tag, although that does indeed put the home among the top five or so most expensive properties in the nation. (The most expensive is the Crespi-Hicks estate, in Dallas of all places, offered at $135 million.)

No, here's the real catch: You can't move in right away.

In fact, who knows when you'll be able to move in.

The property has been in the De Guigné family for 150 years. It's currently owned and occupied by Christian de Guigné IV (pronounced de-GEEN-yay), who was born there 76 years ago, the Contra Costa Times reports, and doesn't plan to leave the estate before he leaves this vale of tears. So it's being offered with the stipulation that the new owner can only move in after De Guigné dies. Quite a contingency, that "life estate" arrangement.

But here's what the farsighted buyer will get: 16,000 square feet of living space and, perhaps more stunningly, 47 acres of land in Hillsborough, Calif., halfway between San Francisco and Silicon Valley -- in one of the most expensive ZIP codes in the nation. The mansion was designed by architects Bliss & Faville and decorated by interior designer Anthony Hail. Its "grand-scale ballroom, living room, library and pavilion are aligned to open to a pool courtyard, revealing sweeping views of San Francisco and the East Bay," the listing at Sotheby's International Realty says. (My quote omits the listing's inexplicably eccentric capitalization.) The listing doesn't reveal the number of bedrooms and bathrooms, but it's safe to say that the Contra Costa Times' characterization of bedrooms as "numerous" is accurate. The real estate blog Curbed says the estate has seven bedrooms, nine bathrooms and a "flower-arranging room"; the Contra Costa Times puts the number of bathrooms at 11.

And while $100 million might seem stratospheric, a new neighbor over in Woodside recently paid the highest on-the-record price ever for a home in the United States: $117.5 million, for an estate on a mere 9 acres.

Any takers?