Surrey passport office on a Monday after 11am took me 20-30 minutes to go from street line-up, to elevator ride, to line-up ##, to ## called, to passport processed.
Not bad!
If you go right away in the morning....it takes longer because everyone thinks that way...by lunch the line-up is gone.
P.S.-Do yours online (e-passport application) print it off and go in....sooooooooooooo much faster because all the information is done for them.