Well engineered, well manufactured, experience in reading instructions helps - DO NOT RUSH - assembly took about 9 hours total with an adult daughter's help for 1 of those hours. Be careful of power drill application - follow the directions on this matter. Did I mention that it is important to follow the directions and not proceed until you understand what they are asking you to do. I still haven't put on the door hardware yet but how hard can it be if I just follow the directions