Twitter CEO Evan Williams’ is supposedly building his own home which is why his current abode is now on the market. Located at 601 4th St in San Fransisco this penthouse loft at the Heublin Building is for sale at $1,498,00. Features include 2 private enclosed bedrooms (they don’t look too private to us), a newly remodeled kitchen, hardwood floors and a 110″ high definition projector. The official listing doesn’t mention the MLS# or the square footage (1,792 sft). You can find more information at Curbed.com.