DIY Cold Frame Using Old Windows

10 Materials
4 Hours
This DIY Cold Frame is easy to make using old windows. Plans for how to make a cold frame from old windows and keep your cold frame warm during winter. The material listed will build a 41" by 45" coldframe. It's a good idea to test whether there is lead in the paint on your old windows with a lead paint test.
  • Without a doubt, this project was made easier with 2 sets of hands.

  • With the plywood on the floor, we set the windows up on the plywood in the size we wanted the finished Cold Frame to be.
Once we had it how we wanted it...we traced the outline of the windows on the plywood. Mark your outline on the outside of the window. You want the plywood to cover all the edges of the windows. It wasn't perfectly symmetrical as one window on the roof is offset such that we could hinge it to the other one; one roof window is secured permanently, while the other is hinged. You can see that in these pics. 
  • I would HIGHLY recommend priming and sealing your plywood side panels before you cut them. Also, seal the bottom of the plywood that will be on the ground and the part of the exposed window frame that is hinged with the polyurethane. We had to do this after the Cold Frame was built and realized it would be much easier to do it beforehand. You can then touch up the cut sides easily after you cut the wood.
  • We cut out 2 side pieces based on the outline. We cut the original one and then used that as the guide to cut the second one.
  • We then nailed the plywood sides of the Cold Frame to the windows, making sure all our edges were squared up.
Turned it on its side and nailed the other side to the windows.
  • Then we nailed the stationary roof window to both sides.
  • Once the 3 windows were secured to the 2 sides, we hinged the final window to the stationary window.
  • Assuming you primed and painted before you nailed everything together, you are done!
Since we are in the Southeast and don't get the prolonged cold and freezing weather of some of you, I'm pretty confident I can keep my lemons in the cold frame all winter. However, if it looks like we are in for a prolonged, bitterly cold period, I will run an extension cord to it and place an outdoor spotlight like this with a 60 W bulb in it. For what it's worth, LED bulbs don't put off quite as much heat as incandescent bulbs, so you would want to stick with incandescent for this task.(At which point I can call it a Greenhouse again?)I might also experiment with filled water bottles painted black which will absorb the sun's heat during the day, keeping the air in the cold frame warmer at night.And if it seems necessary, I will also cover the cold frame with a blanket or tarp, ensuring that it stays even warmer.If you are in colder climates, you can use your cold frame to extend your fall and spring growing seasons, as well as grow your winter greens like spinach, kale, etc...protecting them from the harsher elements. In fact, a cold frame will create a little microclimate a zone and a half warmer than your actual location.
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Lynn @ Nourish and Nestle
Want more details about this and other DIY projects? Check out my blog post!
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  • Cheri Tanner Cheri Tanner on Jan 27, 2020

    Ok, I just read this over does one get into the "cold frame"? I see that there are plenty of windows but NO doors to get in. Did I miss something? Like a paragraph or something??? Great idea though! How do you mow the lawn underneath????

  • Bambi Bambi on Jan 30, 2020

    D asks the question about sitting the whole unit on a pallet so the bottom plywood base doesn't rot. And other people are asking how you mow the lawn underneath because the pictures just show it sitting on the grass. So does it have a plywood bottom or does it just sit on the grass. And how do you lift a heavy pot up and over the windows to put it inside. Seems like you could hurt yourself, strain your back, lose your balance and fall into the windows. I love the idea but it all seems a little confusing and from other questions I see I'm not the only one wondering about this. Could you please clarify?

  • Dianne Smith Dianne Smith on Feb 03, 2020

    Why is called a cold frame? I love this!

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