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Urban Greenhouse

Please feel free to email any questions to koolex11@netzero.com.  I'll be more than happy to help you out.

The House:

Here is how I built my small (4X8) greenhouse out of old windows.  Total cost was $300, but you could do it for much cheaper with some resourcefulness and an eagerness for scrounging materials!



  After many gardens, some successes and some failures,  I moved for the first time to a city row home.  There is a small back yard, but in it grow 2 enormous pine trees.  Lesson #1: evergreens kill soil for all but a handful of species, and few if any of the survivors are delicious.  I wanted to grow FOOD.  Even store-bought potting soil, used in a container garden, was useless after a year of being left outside. If I wanted to be an urban farmer, I had to set my mind on building a "green"house.

First, I found some old windows around town.  I also sent an email to co-workers, offering to help them get rid of any windows they had been meaning to throw away (thanks Paula Brodt!) and before I knew it I had more than I needed. 

Great ways to find free (or very cheap) windows:

            Drive around on garbage night
            Email your friends and co-workers.  You would be amazed how many people have them laying around and are more than happy to be rid of them!
            Contact some renovation contractors or replacement window specialists.  What do you think they do with the old windows?
            If you strike out with the above, or you just don't want to wait, your local junk dealers usually have 100's!


Step 2:  It is definitely easier to design the frame around the windows, rather than trying to find windows to fit the frame.  I laid them all out and measured them, trying to come up with the most symmetrical configuration.  I then drew a blueprint and got to work.


I covered the back side with plywood because a) it faces south, b) there is a fence that I didn't feel like dealing with, and c. I wanted to keep my options open in case I needed more ventilation (I did need it) etc.

Notice the windows fit the 2X4 frame.  In some cases there was a gap (up to 3"), but I covered the outside with plywood so you can't tell that EVERY window is a different size.  I tried to match up the size of the glass panes, then did my best to even up the outer perimeter of each frame with a table saw.


The four corners of each window are held to the frame with screws put in diagonally.  They can be removed easily from the inside, but do not open.  When deciding on whether to make windows that open, I considered the following:
                A. The purpose of a greenhouse is to extend the season (I wanted a 4-season) so easier and cheaper to weatherproof this way.
                B. I have a roof vent running the entire length of the shed to allow heat to escape.
NOTE: In retrospect, I should have designed it so ALL the windows open.  As you will see, I later had to buy an expensive exhaust fan and shade cloth for the roof to keep the temperature down. On one 88 degree day, the inside of the greenhouse measured 121.  I also ended up abandoning trying to heat it through winter.  Oh well, I made this site to give you the benefit of my errors.


No I did not run out of windows.  I have very special plans for that lower panel. Eventually I will use that to incorporate aquaponics. 

The greenhouse sits on an old concrete foundation, but I used stone to level the area and provide drainage under the structure.

The corrugated plastic roof, fitted foam insulation and special neoprene washer fasteners are all sold in the same area at Lowe's or Home Depot.  There are usually 2 grades of clear plastic, and In this case it is much wiser to buy the expensive stuff.  The cheaper grade of plastic shatters when put under stress (cutting, drilling, dropping) and I don't even know why they sell it. Trust me, spend the extra money and save yourself the trip to return it.  Suntuf or Tuftex are the brands.

Here is where you could save money: with the right windows/design, the roof could also be made out of recycled materials.

When drilling holes for the hex screws, be sure to make the hole about 3/16" larger than the size of the screw (or whatever the instructions recommend) to compensate for expansion/contraction of the structure.

To waterproof even further, I put a dab of caulk in each hole before attaching the screws.





I just cut a doorway out of the shed wall, so you enter the shed, then turn left to the greenhouse.


For further weatherproofing I used a can of  expanding foam.  Once cured, I trimed away the excess with a knife.


I also caulked around the windows and the seams in the plywood outer wall.



Finally, a coat of paint. Trim and gutter to follow, as planting season is upon me.


You can see inside is the skeleton of my ingenious shelf system. 

Click to continue to the hydroponics system.


Hydroponic system

Subpages (1): Hydroponic system
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