Twitter's CEO is building a new home with his elegant, designer wife. But it won't be ready until at least 2010. The couple's existing penthouse is, perhaps, unsuitable for them and their new baby. The solution? A temporary mini-mansion.

That, at least, is the best explanation we can come up with for why Ev and Sara Williams are selling one house, buying a second and building a third, all at the same time. Their old penthouse was a two-bedroom in a gritty part of San Francisco Mission District, while the home they just bought reportedly has three bedrooms, a guest house and is in the yuppie-family haven of Noe Valley. The acquisition, reported today by SocketSite, can be confirmed with a search on the records website PropertyShark:

The Noe property, on the market for a full year and designed by architect Owen Kennerly, seems like a sensible place to wait out the construction of the new home; a comfortable interim house like this should allow the couple to complete their own house without rushing the job in response to the pressures of a new baby, fast-growing internet startup and cramped apartment. Plus, they got it for 16 percent under list.

That, at least, is what we'd tell ourselves if we had $2.4 million to drop on a temporary pad.

UPDATE: Williams writes, ""We're not building another house. (Also, the penthouse isn't in the Mission.)" The first assertion is very odd: The Times quoted Williams in March saying "we're building a modern house;" at that point the house below had been finished and listed for sale for four months. Perhaps the project proved to overwhelming. We've asked for clarification.

UPDATE: Williams writes, "we *were* building a house."

Pictures of the house below via SocketSite.



Guest house.