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This is a brief guide on how I took some old windows from houses they where tearing down in my neighborhood and turned them into a small greenhouse in my back yard. I collected the windows over the course of a year and a half and the build took about 3 months, spending one day a week on it. I spent about $300 for the lumber for the frame and screws, caulk, latches, etc. That's almost 10% of what a greenhouse kit would cost. The size I built was 7 ft high x 10 ft deep x 6 ft wide. But the size of your greenhouse will depend on your windows and the time you want to put into project.
Step 1Collect Windows and Plan Two Pair of Equal Sides.
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Look for old windows and save every one you get. After you have many, lay them out and play a game trying to make two pairs of "walls" both the same height. Two to three inches won't matter as you can cover the difference with wood. Smaller holes will need to have glass cut for them or filled with something else. Keep in mind that one end will need a door and the other a hole for a fan.
There should be no regulation preventing the use of used windows with single pane, single or double strength glass.
I to am in the process of trying to collect enough old windows to build a greenhouse of a reasonably usable size.
In the meantime, I got really lucky when a couple of neighbors replaced their large "patio" sliding glass doors. They each consisted of TWO glass panels [one fixed and the other sliding], giving me FOUR large double glazed [insulating] panels.
And the REALLY good thing about them is that they are both made with TEMPERED glass which is genrally much stronger, AND IF broken, shatters into hundreds of small "pebble-like," pea gravel sized pieces which are not as dangerous as the shards from broken ordinary glass.
Not yet having enough windows collected to build a greenhouse, I used the 4 double insulated panels to make four COLD FRAMES, which work great. Because of being double pane insulated panels, they each are very heavy, but with proper [ergonomically speaking] handles and automatic [gravity-pendelum action] prop rods, they are managable.
I made the cold frame bases of treated 2x4 framing, with the cavities filled with discarded Styrofoam sheeting [picked up wherever found discarded], covered with 1/2 inch treated plywood on the outside, and 1/2 inch untreated, but exterior grade, plywood on the inside. I then lined the interior walls with a construction water barrier film to give some limited protection to the plywood. To facilitate replacement of the interior plywood wall panels if it should ever be needed, I assembled the entire structure with Galvanized drywall screws.
Before varnishing, I carefully caulked all exterior crevices that might allow entry of weather [wind or water]. Finally, ALL outside wood exposed to weather was sealed with a properly applied [per label directions] triple coat of Polyurethane Varnish.
Unfortunately, I have no photos, AND have sold both cold frames a few years back. A "out-of-towner" guy made me an offer I couldn't refuse [$500 each], and so I've got to start over in the process of collecting tempered glass double insulated panels.
A neighbor made a green house of windows, he set it on concrete from an old barn that was on the property years before.
You can put bricks on the ground perimeter area and place on top of the bricked area...
The taller side is south facing. All of the windows can function(open/close) save the two big picture windows on the east and west sides.
I added 50 gallon water barrels to disburse heat gain throughout the night.
Next to add are solar panel and fan.
Question...I have access to two solid pieces of glass from old shower doors. Is this glass okay to use? (I understand it is tempered or shatter-proof.)
Thanks!