When Twitter was building a second dining room for its Market Square headquarters in San Francisco, architect Olle Lundberg was tasked with with making the potentially awkward space feel comfortable.

Where its main cafeteria is located in a grand double-height room with an adjoining rooftop terrace, the only available space for a second cafeteria was a long, claustrophobic interior room that stretched across almost 7,000 square feet, stunted by 10-foot-tall ceilings.

"No matter how you decorated it, the square is just long. The ceiling’s too low," Lundberg says. "It’s always going to feel like something’s not quite right."

His solution: Break up the space by dividing it into multiple rooms. To do so, the Lundberg Design principal turned to Craigslist, and a pair of log cabins built in Montana in the 19th century. Read More