Facebook Inc. could expand to as many as 9,400 workers in the next six years, an employment boom that might require construction of as many as five more buildings at its new Menlo Park headquarters.

Workers roam with laptops, meet on sofas and scribble on walls at Facebook's new Silicon Valley headquarters, where rusted steel beams, exposed heating ducts and plywood-covered corridors are part of ...

Facebook has outgrown its campus in Menlo Park, just south of San Francisco, so Mark Zuckerberg hired famed architect Frank Gehry to design "the largest open-plan office in the world" as a spillover ...