This is my first posting in many years but when I saw this I had to tell my story. My husband and I built our second greenhouse last year and just love it. We had new windows installed and used our old windows for the glass. First we built a 12 by 16 frame out of treated lumber with a fiberglass ribbed roof. The first year we used plastic for the sides and the second year after my husbands shoulder surgery we put in the old windows. We hinged three windows for circulation when needed and we should have put in one more. We can fix that later on when the plants are out. Anyway it works like a charm. The benches are made of cement blocks pillars and we put closet wire shelving across the top. The openings of the cement blocks are filled with 2by4's making another shelf for my flats. By using the wire shelving, the plants have lots of drainage and they don't rust. We have the shelving in a U shape. Electric was added this past fall and has been very handy. I used extension cords before and this is much better. During nights when the temps get to freezing, I turn on a radiator type heater and a fan pointed to the ceiling to keep the air circulating. The temp keeps about 10 degrees above the outside temp. I do not use this all winter, just for starting seeds in the spring. Works great for us. This spring we have to paint it. I forgot to mention that we have this connected to a wooden shed that is 12 by 24 feet. Linda44

Lorna, I'm just about 80% done building my "old window" greenhouse . Do you already have your windows or do you need to buy them? I bought old wood-framed "paned" windows from a salvage company near where I live (cost $5/sq/ft.  but I got lucky and found a 5Âx 8Â, 18 pane window for only $100). Some of the panes needed reputtying (not very difficult to do, bought glazers putty at the hardware store). I wanted the look of an older, established greenhouse; hence the wood-framed paned windows. I also bought an old wooden storm door with 6 windowpanes in it. The whole thing looks cool already and IÂm not done puttying and painting yet. As far as instructions go I didnÂt have any. I just framed it up (a three sided "shed" against the wall of my garage), using pressure treated corner 4'x 4' posts sunk 2 1/2 feet in the ground, a few 2'x 6's and 2'x 4's to tie it all together. I was concerned about the weight of the slider "roof" (read below) being so heavy, so I used 4Âx 4Âs as rafters (probably overkill, but I really really didnÂt want the glass overhead to come falling down on anybody in the future.) Then I set the windows into the walls where I wanted them, and covered the rest of the exterior walls with exterior 5/8" sheathing. I used a sliding patio door (1/2 of a 6 slider) for the roof, along with two other smaller windows. The total finished size of my greenhouse is only 5Âx9  small, but dandy. IÂd be curious to know what your plans are, how big you are making it and if you already have your windows. Good luck and have fun dave

Ah - a different interpretation for viva-say-i. The word actually means "farmer" in Tamil - my native tongue. MollyD - thanks for the links. All those look great - not exactly what i had in mind. What i had in mind was a small greenhouse that i could somehow mount on the outside, preferably something that i can take down once the winter goes by. I have a double-hung window that's 32" wide x 64" tall. The way i am thinking about this, during really cold nights, i could just raise the lower window and voila - the greenhouse will be heated - the screen on the window will prevent the critters that hang-out in the greenhouse from entering the house (keeps the wife happy that way) During the day or warmer nights, i can keep the window closed. I am quite sure this is not the first time someone has thought of this. Please share your experiences...

Marcy, If I may, make a couple of suggestions. My personal recommendation for you would be to use a fiberglass window. Fiberglass is impervious to moisture, chemicals, salts, etc. for your pool environment. It does not conduct heat or cold (thermal performance) and is not affected by extreme heat & cold either. Vinyl expands and softens (melts) at high temps, and contracts rapidly as it cools. This will cause it to become brittle with age. Aluminum conducts heat & cold, wood requires Paint & maintenance. So I would recommend fiberglass inside and out for your design. Most underground storage tanks, chemical equipment, and boats are made from fiberglass because of its strength and because it performs so well. Vinyl is the most cost competitive product sold today, however, I personally would stay far away from vinyl if your intent is longevity of your windows. Aluminum windows are still popular in your part of the country, however, even thermally broken aluminum will sweat in that environment. Let me qualify "Fiberglass Window" by saying an INSULATED (cavities foam filled for sound reduction if sound reduction is important) fiberglass window frame. Also Be very careful of what some consider to be or call "fiberglass" and what truly is fiberglass. For instance, certain companies have products that use the word "Fiber" in their name, but it is merely a composite of wood, vinyl, and fiberglass strands for reinforcement. Thats NOT fiberglass. True fiberglass is thermally set during the manufacturing process, and once cured (in about 20 Minutes) its shape cannot be changed by re-heating or melting. In the interest of full disclosure, I work for a distributor of winodw products, and thus have gained a VAST education in the subject of Manufactured goods & thermal performance. Thus, I wont recommend a specific product, but I will tell you that spending a little more for a fiberglass frame in your area of the country will give you many more years longevity, & they can even be painted (even dark colors) without voiding the warranty. If you think about it, Fiberglass windows & Glass (key components are derived from silica sand) are both made of the same raw materials. Therefore, what small amount of expansion and contraction they do have from hot and cold temps is minimal, but they will move at the same basic rate. This prevents separation of frame & glass, and degradation of the product over time. Tri Pane windows are expensive, and will improve your thermal performance and your STC/OITC rating, but not enough to justify the expense unless you are in a severely cold climate. If noise & thermal control are your primary concerns, I suggest you ask any window seller to SHOW you their STC/OITC ratings, their thermal (NFRC) ratings, and a Corner cut sample of the product you are interested in. Much can be learned about quality and serviceability by these 3 things. I do however recommend you use at least a doubled layered (LowE2 - 1 Layered and 1 sputtered) coating on your windows. Double coat low-e reflects heat gain in the summer and retains heat in the winter. It provides some solar heat gain during the winter months as well. This is difficult to explain, but the mental picture is this: The secong coat is sputtered on and done so at an angle. The reason for this is because the angle of the sun relative to the earth is higher in the summer and lower in the sky in the winter. Therefore, in the summer it reflects the suns rays and the winter it allows more of those rays to pass. Since the area is enclosed, without some sun protection, you simply wont be able to cool the area when competing with the power of the sun. I suggest you use solar sun shades for summer time as suggested above, this way you can manually control summer vs winter heat gain, and even on an hour by hour basis. Besides, they will also provide you privacy for a night swim if desired. As for your plants, Low-e coatings still allow a generous portion of the suns spectrum through to nourish your plants. My house is covered in vegetation that performs very well behind these coatings. I hope my knowledge helps you better understand how these things work. Best of luck! JH