Building greenhouse from windows

I was recently able to salvage about thirty or so windows from a neighbor's trash pile some are even double paned; and was wanting to build some kind of greenhouse for my seedlings and plants this coming year. Problem is I have absolutely no idea where to start other than a simple cold frame.
  7 answers
  • Douglas Hunt Douglas Hunt on Dec 19, 2014
    If you do a search for "greenhouse" and "windows" using the box at the top of the page, you will find a lot of inspiration, including this wonderful project:

  • Angelia Christenson Angelia Christenson on Dec 20, 2014
    Check out our Greenhouse project far as HOW TO BUILD its pretty much just a box frame and he screwed the "walls" together by literally screwing the windows together. The roof is thick plastic roofinig but needs to have some sort of PITCH cause he forgot that part and we had to just drill holes in a few spots and let it run into buckets when rains...ha. (first heavy rain is sagged to the inside horribly, but on a good note the buckets with water can be used to HUMIDIFY at

  • Jeffrey Landis Jeffrey Landis on Dec 20, 2014
    I salvage & re-sell architectural items, mostly windows and occasionally people buy them for this purpose. You've gotten some good input already, so I don't want to beleaguer the point, however, there are a couple things to keep in mind. If you're going to the trouble of building this, I'm presuming you want it to last for many years. Make sure the windows are up to the task. You don't mention how old or what type of material the windows are, but I'm guessing they're wooden. The overall thing to keep in mind is that you are not just making something decorative, but a small building that serves a specific purpose. Greenhouse construction & design are an art and a science. Siting (placement and direction it faces) are important. It should be set on a flat area that gets full sun all day and the gable ends should face true north to south to maximize lighting and to allow natural ventilation. The whole thing needs to be anchored, staked or otherwise tied down with solid footing. Technically, if you live in a zone that includes freezing/thawing cycles, there should be footers in the ground that are seated below the frost line. If that's beyond the scope of what you're willing to do, at least set some posts or drive steel posts, at each corner and use something like concrete landscaping slabs or blocks set below the surface of the space for the walls to rest on. The inside floor area should be paved with this kind of material anyway, so you can just extend it. Whatever the case, plan for stability in the high wind. If not it could do a Wizard of Oz thing. Each window should be gone over carefully to repair loose joints, replace cracked glass and the glazing should be removed and re-done (don't just touch it up), old glazing deteriorates quickly once it begins, so if there is any that's missing, cracked or loose, it will all come off soon. It's a lot easier to do it now than after the fact. Next, strip, scrape the paint to bare wood, prime it (2-3 coats) ALL wood surfaces with a high quality primer such as KILLZ. If the "chippy paint" look is what your after, replicate that using any of the many crackle effect paints rather than trying to keep the current flaking paint. Especially if you're growing anything for consumption. The paint, just like the glazing will continue falling away when exposed to weather even in temperate climates. Most paint manufactured prior to 1972 contains lead. When the paint gets onto the surface of the soil and plants, it's taken up by the plant along with any other minerals. The soil will be permanently contaminated at this point. Also, remember windows are designed to shed water, but only the outside (the glazed side) and more importantly only designed for vertical applications (walls). Don't use the windows for the roof. Even pitched, water and snow will pool in the recesses, rot the wood and add weight that will cause them to cave. This is not only annoying, but dangerous. While windows are intended for vertical application, they are NOT designed to be load-bearing structures, so the suggestion to mount them to a frame is a very good one. Consider something like PVC, or some type of light-weight metal and attach the windows in some fashion that allows you to remove them individually if one should need repair or replacement without affecting the others. One poster suggested a plastic roof which is good. Be sure to make it two layers of single ply with an air gap in between, or use the rigid, corrugated type if you can afford it. It's light weight which will reduce the stress on the "walls" and add insulation. Be sure to research greenhouse construction because there are airflow and heating considerations or the plants will not breathe and will be incinerated on the first warm sunny day. The roof needs to be able to roll back or louver open, a fan and vents should be installed to circulate air, etc Good luck.

  • Gail Salminen Gail Salminen on Dec 20, 2014
    @Diamond Chamberlin Doug's advise is right on - the search will pull up all sorts of posts with many styles. Here is one I found Do post your final results.

  • Jen Jen on Dec 20, 2014
    Yup..just google greenhouse using recycled windows!

  • Diamond Chamberlin Diamond Chamberlin on Dec 22, 2014
    Lots of awesome suggestions y'all ! Thanks so much for all the advice. I live in Georgia and the weather is pretty mild here most of the year so I will be starting on this project in January and will be using as many upcycled or repurposed materials as I was able to bring with me to the new home. I've got 12 foot long lumber that was leftover from a nearby churches pews they threw out. Lots of windows obviously and much more I haven't mentioned . Will make sure to show pictures as I go along and he finished product. Thanks again !