The latest example is an empty lot in the Glen Park neighborhood.
RELATED: Silicon Valley estate expected to become most expensive in Bay Area
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Three years ago, the lot sold for $950,000. Since then, the price has doubled to $1.85 million.
"It seems like a lot of money, but when it's all said and done a 4,000-square-foot house that is close to restaurants, walk around the corner and go to a French restaurant, a sushi restaurant, it's a great spot," said Pete Brannigan, the real estate agent who is listing the lot.
Brannigan jokingly call this area, the "tip of Silicon Valley." The BART station and the entrance to I-280 are just two blocks away and those company buses stop here all the time.
But the main selling point are the site plans that already exist.
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The owner of the property, who's an architect, spent the last three years going through the approval process.
He showed ABC7 a rendering of what could be built, a 4,000-square-foot home with four bedrooms and five and half bathrooms.
"If you had an approved site plan set, I would think that would make the property a little bit more valuable than if you did not."
According to Build SF General Contractors, the going rate to build a single family home is anywhere from $500 to $600 per square foot -- so a 4,000-square-foot home here would cost between $2 million and $2.4 million.
"Prices are crazy and, at some point in time, it is going to tap out. This cannot keep on going," expressed Bill Kucera who lives in Glen Park.
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"I'm not shocked but I am a little surprised," said Mary Stafford, who lives in San Francisco.
San Francisco has eclipsed New York City as America's most expensive city.
Brannigan agrees and tells me, "Way long time ago."
So far, a dozen people have already asked to see the architectural plans.
See more stories about the housing market.