Overall, the greenhouse is a good value. The frame is easily assembled and it comes with some additional bracing that is not on the slightly smaller tunnel. However, there are steps to take to make it hold up over time. First, I attached a base of 2x4's on edge around base of the tunnel frame and attached the tunnel frame with 3" screws every couple of feet. I added a braces in the middle of the tunnel going up to the cross bars. This provided additional lateral support for the tunnel in the middle and will help with support snow load. I also foil taped all the bolt heads to prevent the heads from rubbing holes on the cover. I created a frame around the doorways with 2x4's as well. Finally, I stapled the cover to the wood perimeter frame and around the doorways to get the cover tight to shed water and snow better and to prevent any sagging between the tunnel frame supports where water and snow could settle. Attaching the outside of the door zipper to the wood door frame keeps the end panels from flapping in the wind and the zippers work much smoother. I live in the mountains at 9,000 ft and get a good bit of snow and a lot of wind. Without all these fairly easy modifications the tunnel would not hold up.