As long as it is not in an exposed spot (no greenhouse should be in a very windy spot IMHO) then you will have no problems. Mine has done fine all winter as it has a high fence near it sheltering it from strong winds. My neighbours has no pains left as he built his on a hill on prevailing wind.

I have had no problems with my polycarbonate greenhouse either...I havn´t even got it on a proper base...I just have heavy paving slabs round the bottom...and it isn´t realy in a sheltered part of the garden...that my expierience.

My Alton ones sit side on to the prevailing winds. It has blown down fencing but not touched these. If you look at my pictures you can see how they are constructed. The sides and roof bolt and clamp together. Then the whole thing bolts down onto concrete base sections that literally weigh a ton between them.

I have a ten foot square one still to erect this year, and you can barely lift the longest sections for this one's base they are so heavy.

In May 2013 I put a hot tub in the yard for my wife. Come October she said she wanted an enclosure around it for the winter. After much research I selected the Palram Silver 8x8-foot Snap and Grow Greenhouse.

I made a base for the greenhouse out of 4" X 6" X10 foot pressure treated ties cut to the 96.5 X 96.5 inch specs in the plans. It is square and level, sits on my concrete block patio, and should provide a solid base for the greenhouse. I would not consider buying this greenhouse unless you plan to put it on a solid, rigid, square and level base. It is too light to just sit on the ground.

Assembly requires a minimum of two people as there are times when one has to hold while the other places parts in place or puts them together. Definitely use silicone spray as recommended in the instructions as some parts are very tight fitting, which is good. On a few occasions we found a rubber mallet helpful to get that last little bit to go in and seat properly. And be sure to follow the sequence exactly as presented in the manual. All parts are well marked so you should have no trouble matching up pieces to the instructions.

While not absolutely necessary I would recommend having a sheet metal seamer tool such as the Wiss-WS6-6 hand seamer. Some of the parts have thin edges and can get slightly dinged or slightly bent during shipping. Or, if you drop something, you can bend the edges making assembly nearly impossible. With this tool this was not a problem at all as this straightens them out quickly and easily.

My first concern was how it was going to handle wind. Seems this will not be an issue. Since putting this up we have had winds of 25 to 30 mph with gusts to 50 with no problems at all. The greenhouse is doing just fine. I see no evidence of any strain on the building. As long as you have it solidly anchored I think it will handle wind just fine.

My other main concern had been snow. We have come through one of the worst winters I can recall. Our typical snow fall is a total of 25 inches. We are over 55" this winter. We had two snow falls in excess of 14 inches. One Snow fall was very wet and heavy. But, due to the slant of the roof very little stayed on the roof. I think during the wet fall we might have had 2" on the roof before is slid off. We have had winds in excess of 50 mph on several occasions with no problems at all.

As of now everything seems fine. I am no longer concerned about snow or gusty winds, at least to 50 mph and I am sure it will take more than that. But it must be anchored to a level and square solid base or it probably won't do well. Hope you find this helpful.