Exit the empty office. You'll exit, you should be facing down a hallway with a fire extinguisher in a case directly to your right. There's a red pipe a long the top of the wall. Walk straight down the hall and take the first left into another empty office. There's a red pipe running along the ceiling of this office as well. In the opposite corner there's another brown door. Walk towards the opposite corner and stay just to the right of the brown door and pillar. Standing so, to your left now is the open brown door and the pillar, straight ahead is a translucent glass wall and behind you is the door you came in. Standing there, in line with the pillar on the left, you're done.