On the good side, my BC Greenhouse order was well made and well engineered. For instance, the aluminum pieces were cut very precisely.
On the other side, perhaps because I got the "economy" polycarbonate, I found out (later) the instructions for polycarbonate installation are in the Appendix section of the paper user manual. And the DVD, while an excellent idea, did not run. Basically, you have a really big puzzle, parts of which I took apart once, and sometimes 5 or 6 times to get it right.
My strongest advice- do not try to install the greenhouse yourself. If you do, have at least one helper and set aside 4 or 5 days to erect it. The builder (whom you bought this through) can put it up in one day.