I see a lot of beautiful greenhouses described here and in an attempt to not hi jack someones thread,, I will describe my hoop house-greenhouse. It has a gothic roof and is made out of heavy tubing and covered with plastic. I bought mine locally, Rimol Greenhouses out of Hookset NH calls it its Eastpoint model, and it is about $3500 for a 20 by 48 one with the base package and roll up sides. It is about 12 foot high in the center and has stood up well to about 10 years of NH winds and winter snow. Has a double layer of plastic and a fan keeps air in that and acts as insulation and helps keep it tight to shed snow. I used a 1 1/4 inch hammer drill bit to drill holes in the soil and drove in tubing and the hoops are fastened to the pipes and a 2 by 8 board is fastened to the pipes and sits on the ground. I used screw in anchors to hold the board down, 4 per side, and have had no problems other than the cold getting under the board. The whole thing will fit on one trailer, can be taken down and reassembled, is not taxed by the town, plastic lasts about 6 years, about $500 to replace it, and I use the reject plastic on other projects. I put it up totally alone in about 2 weeks spare time with no experience, and a group could put it up in a day. I built the end walls out of plastic, south wall, and wood ,north wall and have always been happy with it. Scrounged up the fans, old chicken house fans, and heat with wood. Unlike the solidly built wood and concrete ones, these could be put away for after TSTF, be put up on rented land, be taken apart and sold if you want a bigger one or lose interest, or want a more solid one. With no heat and one layer of plastic, they are called season extenders, and usually only have plastic on them for a few weeks in the spring and fall. Friends use them with growing greens and chickens wandering around the place and with netting on part of the roof for free range egg production and the chickens love them. know of people who use them to raise game birds in, use them to dry firewood, use as garage and workshop space, place for kids to play when it is cold or rainy, and so on. They are not a classical greenhouse, and if you live in a rough climate, like NH, I would strongly suggest you buy a less fancy package from a local firm that has several years of experience in building in your area. There is a lot of junk out there and if the price is really low, the quality may be the same. Look up hoop houses or high tunnels some day when you are bored. The space is so pleasant that you may get hooked on them like I did. They aren't real cheap, but they are a really good investment in both lifestyle and SHTF. A guy out of Texas sells a hoop bender that allows you to take a piece of electrical conduit and bend it into a low hoop to cover a 4 foot wide raised bed in the spring and fall with plastic to hold in the heat, and during the summer with that white fabric to keep out bugs, or shade cloth in order to keep greens from bolting. It is a win win for me as I use my old plastic and the hoops, drive a piece of rebar in the ground to anchor them in place, last nearly forever.