How to Make a Cold Frame from Old Windows

Spend a few weekend hours crafting a mini greenhouse from a salvaged window to yield months of extra gardening.

The salvaged window you use as the cover will determine the size, shape, and style of your cold frame. The curving lines of the Gothic-inspired window we used made the construction of this cold frame a bit more complicated than building a rectangular structure; still, the procedure was straightforward. For our cold frame, barnwood composes the straight sides and tin the curved and pointed end. You can also use salvaged or purchased wood and paint it or leave it untreated.

  • Start to Finish 2 Hours
  • Difficulty         Projects Kind of Easy
  • Involves Power tools

What you need

Tools

  • Tape measure
  • Saw and hacksaw
  • Power drill and 1/4-inch bit
  • Screwdriver

Materials

  • Salvaged window
  • Nontreated cypress, cedar, or other wood for sides
  • 3 feet of 18-gauge perforated-steel angle
  • 1/4-inch-diameter by 1-inch-long hex bolts and nuts (x25)
  • Washers to fit hex bolts (x16)
  • 3/4-inch No. 8 wood screws
  • 3 1/2-inch steel or brass hinges

How to do it

Step 1 Cut Wood Sides

Cut wood for sides, each 18 inches tall and matching the window's dimensions but allowing the window to overlap the cold frame by 1/2 inch.

Step 2 Attach Side Pieces

Join the side pieces, using 18-gauge perforated-steel angle. (Cut pieces with a hacksaw.) Use the 1/4-inch hex bolts to attach the angles to the wood, placing a washer between the head of each bolt and the wood.

Step 3 Attach Hinges

Attach the hinges to the underside of the window frame, using 3/4-inch-long No. 8 wood screws. Lay the window atop the box and use the hinges to mark the location for drilling 1/4-inch holes on the outside of the box. Use 1/4-inch hex bolts to fasten the hinges to the wood. Place washers between the bolts and the wood.

Step 4 Create Shelves

Stretch chicken wire across the cold frame to keep seed flats off the ground. Attach with a washer and screw. 

Editor's Tip: If you anticipate your flats being heavier than the chicken wire can withstand, use lengths of treated lumber to create heavy-duty shelves.

Step 5 Prop Open Lid When Needed

Your cold frame will warm up quickly when the sun is shining directly on it. Always prop open the lid a little on bright sunny days, even if the air temperature is cool. On warm days, you may want to open the lid completely. Always close the lid before nightfall to preserve the day's warmth.

Similar Projects

RectangleCreated with Sketch. Rectangle Copy 3Created with Sketch.

Comments

Be the first to comment!

Better Homes & Gardens may receive compensation when you click through and purchase from links contained on this website.