There is also an attitude (which I have never been able to understand) that stairs constitute a security risk. I used to work in a government building where all of the stairwell doors locked behind you when you entered the stairwell. You could not, therefore, use the stairs to move from floor to floor - they were only for emergency use. Once you entered the stairwell and the door closed behind you, your only option was to go down to the lobby and take the elevator up (even if you were on the 20th floor!).