Hi Chris, What your building looks exactly what I did. I only have some pics of the frame, but will take some finished pics and post them this weekend. The frame is kind of post and beam 4x4's with 2x4's in between. The rafters are 2x6's and it is now covered in 8mm twinwall polycarbonate. Almost finished but need some trim and paint. I saw the basic shape on another site, but didn't really follow a plan. As for the style, I think the poster referred to it a Mittleider design. Referenced from the Mittleider Gardening Course. Dave Here is a link that might be useful: Greenhouse Frame Pics

I'm about to buy my first greenhouse; one I seen at the Pensacola Jr. College spring garden show in Milton Florida. It's certified to meet Florida wind codes (which was important to me since we've been hit by two hurricanes and two tropical storms in less than a year. It's metal frame construction, with UV protected double wall polycarbonate, a bench all the way around, thermostatic fan, wired for electricity with wiring inside metal conduit with receptacles and overhead light, overhead rails on both sides for hanging baskets, shade cloth on one side attached to curtain rings that can be pulled aside, all for $3300. There's a $180 fee for delivery, set up and tie down. You can put it on a gravel, brick or concrete floor or they will build you a pressure treated floor for $2.50/sf. The builder and his wife are both master gardeners and members of the local garden club. They've been working and improving the design for a couple of years now. I'm really impressed, don't know about you. If anyone is interested, let me know and I'll give you their phone number and/or directions.

If you change your mind and decide to go with an aluminum frame, I highly recommend Poly-tex. Their customer service is unsurpassed. When we put up our greenhouse, we were on the phone with Jon almost every day. He was an enormous help! Their GHs come with all parts and necessary supplies needed. Although our greenhouse was made by Poly-tex, I had purchased it through a distributor, Gothic Arch Greenhouses (I didn't know I could order direct from Poly-tex). If you look at the Gothic Arch site, they have a list of "institutional" greenhouses, built for schools. They even have a list of needed supplies. I also saw a wooden GH http://www.gothicarchgreenhouses.com/institutionalgreenhouses.html It all depends on what the school wants to do with the greenhouse and how much they have to spend. Here is a link that might be useful: Poly-tex

szut, I have built both a wood framed and steel framed GH. First was the wood one. It has survived well but is in need of a repaint and recaulk which was part of the reason I went with steel for the second GH. The other reason was strength. Wood 2x framing is fine for smaller structures. But if you are trying to span longer widths, the size of the wood becomes prohibitive. Especially if you have high snow or wind loads to contend with (I have both). I think you will find Al for structural members is not doable for other than rather small sizes (hobby GHs, etc). Perhaps if you use built up Al girders, but that would be very pricey. Most commercial GHs use steel structures. I ended up going with steel tube arches from a commercial GH, which I made into a lean-to GH on the side of a barn. Given the structural loads it had to meet (50# snow and 135mph wind) it was relatively cheap (no doubt would have been cheaper in less extreme environments). IMO if you can build with wood 2x material, making the transition to steel tubing should not be that hard. You'll need a few new tools (metal saw and drill), but in many ways it was just like working on a big erector set. As a cost saving, you could look into buying a used commercial GH, or at least the frame. That could give you the structural material at a very inexpensive cost. Something that is harder to do with wood 2x material. My steel GH is too new for me to say how it will fair on the maintenance side. But I expect it to handle the moisture better than wood, although it will need some touch up painting no doubt in time.