clvlnd- It all epends how warm you want it. I have a 10' X 15' single pane glass greenhouse in Zone 8. I heat my greenhouse with an electric, 900W/1500W oil-filled heater. It's got a thermostat and I keep it on the lowest setting so the temp stays above freezing. You can usually get a decent one for about $50 (e.g., from Amazon). If you get an electric heater that draws more than 1500W, or run more than one, you're going to blow the breaker on a standard 15 amp circuit, especially if you have anything else plugged in. If you want to use something bigger, you're going to have to seriously upgrade the wiring that supplies electricity to your GH. One of the reasons I can get by with a small heater is that I also have 3 seed-starting mats that measure 1.5' X 4', and each one only draws 100W. I just set my sensitive plants and seedlings on that and everything seems to be happy. Since I usually have a power outage a couple of times during the winter, I have a small propane heater for backup.

mattwenfran "caved in the second winter and I have not figured out how to fix it." I used manual to identify what parts I needed to replace and called Harbor Freight and ordered parts they were very helpful. NOT all parts were available so I had to improvise sometimes, bending pieces the best I could such as the roof ridge was not available at the time so I used a Flat Mending Plate Joiner Repair Bracket to reinforce two piece roof ridge The snow load kit above has now weathered many storms just this week two feet of snow and it didn't flinch. I do rake snow off at some point during the day but I no longer panic when I here a storm is on the way overnight.

Best of luck to you and please post pictures on your progress. I sent you an email, hopefully you got it. Jackie

There are two different sizes of the rigid style greenhouse... 10'x12', and a 6'x8' model... as shown in the link below. If you're going to invest in a greenhouse, and you want something decent without spending a fortune, it would be wise to save up a bit of money and get the 10'x12' model. This is the size we have. Anything smaller is almost a waste, because there would be very little room to move around in, and you would be limited greatly in what you could grow. We waited until Harbor Freight put the larger sized model on sale, and I believe we paid somewhere around $500, if memory serves. We bought it about 4 or 5 years ago, though... and I see the price has gone up a bit. There are some modifications you're going to want to make. This is a relatively cheap kit made with cheap materials... and the directions that come with it are not really as specific as needed. However, when compared to other similar sized professional greenhouses from companies that specialize in them, this is a bargain! I would suggest investing in a concrete foundation or a knee wall to attach it firmly to. Ours was built on pressure treated lumber, and I know it isn't going to last as long as it could. It was reinforced, however, and the panels were attached with silicone all-weather sealant AND the little clips it comes with. The clips alone are not enough, and a good wind will blow the panels right out. How do I know this? I had to go searching for 3 panels after a bad storm wreaked havoc on ours. After we found all the missing panels, which had luckily survived in one piece, we used the sealant AND the clips, and redid the whole thing. By Googling Harbor Freight greenhouse or other similar keywords, or by searching with those same keywords here, at GardenWeb, you can find oodles of great information and upgraded, detailed instructions, photographs and tips from gardeners who have erected one of these kits. Ours has the 4 vents on the roof that open, the double sliding doors on one end, but it's lacking in anything else. In ours, the floor is deep pea gravel over landscape cloth, with a slight grade underneath to allow water to flow out and away. It's not plumbed for water or wired for electric... but I have an outside water hydrant nearby, and a garage close enough to run an extension cord for the fans. This is what it looked like inside earlier this year before I did anything with it. I hadn't installed the fans, and you can see the panels on the floor awaiting replacement... Here, it's a little later in spring, and I'm starting to fill it up with plant materials... Here, the fans are in, and you can see the hose on the floor... This is picture looking at the rear of the greenhouse through the front garden and fence... Here's a few plants I grow in front of it, and the little gravel walk leading up to it... This is the rose "Quadra" growing next to it... I hope this gives you an idea of size and construction, just as an example. The inner shelving was built by a carpenter friend, using lumber and fencing as the table top material. There are all kinds of gadgets you can get... automatic timed fans, drip and mist systems, you name it... ours isn't heated, but it's useful three seasons out of the year. I typically start seeds in the basement, under lights on heating mats, and I move everything out to the greenhouse as soon as possible. I keep my more personal plants and anything I'm worried about inside the greenhouse. This past year was our first using it, and I've learned a lot. I still need to learn more, but I'm on my way! For a decent greenhouse on a budget, you really can't go wrong with Harbor Freight products... as long as you do a lot of reading beforehand, and you have some help knowledgeable about general construction. Hope this helps! :-) Here is a link that might be useful: Harbor Freight Greenhouses