So I was very very skeptical, But once I go the product, I set it up by my self. Easy peasy, the instructions were clear. Corners are are plastic, but for stability and strength I used one inch aluminum straps on the corner and installed rivets on all corners and aluminum straps on base unit, I installed my base unit on treated 2 x 10s for an extra 10 inches of height instead if 55 inches it's now 65 Inches. I also silicone all panels in and out. This unit will not blow away and will NOW stand the test of time, I also installed ground anchors for added wind security 18 inches screw ground mounts which then attach to my 2 x 10 base structure. The only down side was I had to rebuild the two roof vents, I had to drill out old rivets as they DIDNT go all the way through and install new rivets,  and also find a way to secure windowss shut, i used 15# strenth velcro to keep windows closed.  But that was no big deal. I LOVE THIS GREENHOUSE, for the price it's awesome...ENJOY