This greenhouse is horrible. We bought two and returned one. There is NO steel in base at all. The side walls are NOT polycarbonate, just the top panels. The vent panels have no seal and the closing rod does not secure it completely. It leaks like crazy. We only kept one because we had already built it and cemented the legs into the ground with anchors (No anchors are included with the kit). It tells you to use caulking in certain spots (which is not included) but you need to caulk a lot more than that area. We got it on sale for 798.00 and still paid way too much. I have zero faith in the side panels holding up to any real wind. Since we already have it, we will add more caulking and bracing and hope for the best. The plastic wall panels are exactly like the plastic that your kids toys come in. You open the box and then the toy is attached to that flimsy, sharp plastic with zip ties? That is the equivalent of the wall "panels".