Just a head's up for designers using Andersen Double Hung windows, the vertical R.O. is 3/8" shorter on all 400 Series Tilt-Wash double hungs. Since the new R.O. is fractionally smaller then it is not really a big deal, however this may have some bearing in situations where you are coordinating window sills and heads with framing elements.... Obviously its best to be as accurate as possible, the 2003 catalogs have all the new dimensions.