The curtain wall tool seems to have a life of it's own. When I insert the precise elevation dimensions, the part automatically adjusts some of the heights to unusual, unique and unwanted locations that have no relation to what I typed in. After many varied approaches, I finally settled on locations that were not right but as close as the part would allow me to get. I see that most of the questions involve much more complex curtain wall issues so this must not be a concern. Can anyone clue me into how I can control the horizontal mullions? thanx, bill