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.

I have decided that I will make the 10x12 work for me; I will reinforce the heck out of it. I am going to be growing trees, I will need the height. ACK, I went by my Local HF Store today, "Just to Check", I should have my Money by Tuesday... They have the 6x8 in stock $399!, but have never had the 10x12 in stock, Granted when I gave the part number to a stock clerk, and told him that it is listed on Harborfreightusa.com, he said that it is a new item and should be stocking it soon... SOON, how soon, my 20% off coupon, expires on the 18th (Does that mean I can use it on the 18th, or that the last day I can use it, is the 17th) Sigh. I am only about 130 Miles from there Camarillo Warehouse, I wonder if I can do a will-call, and use my 20% off retail store coupon... Leme see, 260 miles round trip call it 9 gallons of gas, at 2.60 a gallon, call it $24 bucks for gas, and 3.5 hours of Driving, one hour for The hassle at will call. Oh, I can not forget the Stop at Canters Deli for lunch for me and my helper, so add another hour, and another $40. Oh wait, I cannot use my car (3 door Saturn, I do not think the big metal framed box will fit in it, so I have to take my wifes truck, Yeah my wife has the truck, what can I say, she is a Red Neck Woman, I think Gretchen wrote that song for her, but my wife is better looking.) Ok where was I, oh yeah Driving the Truck, well I can still average 75 MPH, but the mileage is gonna suck, so that would be $40 bucks in gas SO $40 for Gas, $40 for Lunch, and 4 and a half, ok call it 5 hours of my time... Hmm, well there are about 9 HF Stores, (other than my local store), that are 30-75 miles away, I guess I am gonna have to break down and do that old fashioned thing and let my fingers do the walking. I hope they have it for the same price as the Mail order site. Yeah, I found out on this site somewhere that the www.harborfreight.com site is for mail order/web order prices only, and the www.harborfreightusa.com sight is for retail stores, but it only shows stock items (Not what is in stock, but what they can stock), and they do not show the prices. So does anyone live out here in Southern California, and want a free meal at Canters, and Corned beef and cabbage (my wife makes a Wicked corned beef, she slow cooks it all day), oh yeah and lots of Guinness. (Most of the Guinness will be after it is built. I will be taking lots of Pictures, and using the extra reinforcing mentioned elsewhere on this site. I will also be sinking the Frame (But on wooden supports. I will be sealing the open edges of the Panels with 100 Mile an hour tape (Also know as aluminum tape I think), and then running thin weather-stripping along the inside edges of the panels. I will buy a couple packages of Extra Spring Clips from Charlies, and probably screw in the panels on the roof, since they will not be easy to remove for the summer months. I will probably add extra Triangle corner reinforcing, Guy wires with those funny twisty things and some nice big anchors into the ground. I have a 220 GFI for my Hot Tub near where I will be building it, but I probably should not tap into that for the greenhouse. I do have a couple of Blank spots in my fuse box (Why do they still call them fuse boxes... oh yeah I think they are called breaker boxes now), it was easy for the Guys to run the Power to the Hot Tub (About 15 minutes), but then thats what these guys do for a Living. I probably will not need power to the greenhouse, till Fall anyhow, I will be removing panels and using shade cloth for cooling in the summer. One corner of the greenhouse will be just past one of my Spare Sprinkler heads, so I can tap into that for water, and if I install timers inside the greenhouse, I can have different watering schedules for the watering and the Misting... I assume that is what I should do. One other thing I will be doing is running an extension from the clothes dryer vent to the greenhouse to have the clothes dryer exhaust into the greenhouse... Free Heat and moisture. (Most of our clothes washing happens late at night anyhow. I figure I will till up the ground where the greenhouse is going (Should make leveling it easier), and then I will be flooring it will all the shingles that blew off my roof over new years weekend. Ok, what I am I missing, ahh yes, orientation, if I remember correctly this greenhouse is 10 feet wide, and 12 feet deep. The greenhouse will be about 8 feet south of my garage (I already can see that gap is gonna become a place where you toss all the crap for the back yard, but it would make a good place to park my Garden Tractor). The winds here come out of the South, Southwest, I was thinking of Orienting the Greenhouse so that the door is facing west, I figure that would be better than south, and having the door on the east or north side would be awkward. Does this orientation sound ok? Or should I really put the door on the North side? Now a question for those who have built a 10x12,It is hard to tell from the Instructions, but it looks that the secondary brace for the vents is a separate piece of metal, so would it be possible for me to put all for vents on one side (In this case the North Side), of the roof? I do not think that having those vents facing south and opening up into a 40 MPH wind would be too healthy for the vents or the greenhouse (I am imagining a balloon being rapidly inflated), plus the wind blowing across the vents on the North Side would provide a Nice Low Pressure area, increasing the effectiveness of vents on that side. Am I missing anything (other than the greenhouse kit?) any suggestions, corrections, or Ideas. Sorry about writing books, hopefully most of you find it entertaining, rather than annoying

You have one other option should you choose to do it. Send it back and have them send you another one. Someone on this forum did that because when his arrived it was damaged from shipping. He had another one in about a week. As for waiting on parts I had some parts missing on mine also. I ordered them back in first week of Feb. Still no parts. I made my own and some day when I get the parts I probably will throw them away because the one's that I made is much stronger than what came with it.

Nice job...I see they improved it...mine only came with one vent for each kit. Dave Milwaukee