AMERLIFE12x13.5x9 FT Polycarbonate Greenhouse with Quick Connector Fast Assembly, Large Greenhouses for Outdoors, Swing 2 Doors 4 Vents , Black

This greenhouse came in four boxes. I was impressed with the engineering quality. I would say you need to start out with the ground or platform being level. By doing this, the parts fit together without forcing or redrilling. Second, leave as many screws and nuts loose until all panels are installed. Then plumb and square the greenhouse before tightening fully. Caulking the panels took some time because there are no big gaps. I only used 1 1/2 tubes of caulk to do the entire roof. I also caulked the top panels before installing the lower roof panels making it easier to reach the top ones with a ladder. I put it together by myself and it took about 2 1/2 days (I did take it slow and tried to do it right not fast). Each metal piece is wrapped for protection in shipping and has protective pieces on every single piece that need to be removed before install. It took time to remove all of it, but not one piece was scratched up form shipping. The base installed measures 11' 7 1/2" outside (door side) and 13' 7 1/2" outside (6' walls side). I live up in ND, so time will tell to see how it holds up. I do wish they made this with 10mm panels instead of 6mm, but again time will tell. Overall, I'm impressed with the quality. Mine is set on railroad ties with class 5 gravel for the floor. I personally wouldn't just use the stakes it comes with that can be pushed into the ground as the only means to anchor it. Shipped through FEDEX. Hope this helps!