How to Build a Raised Bed Cold Frame

raised bed cold frame, closed raised bed cold frame: open

Protect your plants from frost with a simple cold frame that sits right on top of your existing 4′ x 4′ raised bed. The lid is held open with screen door closers, and the entire frame can be moved easily when the weather warms up. Cut the lumber yourself, or have the boards pre-cut at your local home improvement store.

Note that you’ll want to measure the height of your raised bed and adjust the cold frame leg measurements as needed. If the bed is taller than 9¼ inches, add the difference to the length of the legs; it it’s shorter, subtract the difference.

Scroll down for instructions, or download our printable PDF guide to building your own Raised Bed Cold Frame

raised bed cold frame: top open for watering

Estimated Time: 2.5 hours*
* less if you have wood pre-cut

Difficulty: Easy

List of Materials:

  • 6 – 1 x 2 x 8-foot boards
  • 3 – 1 x 4 x 8-foot boards
  • 2 – 2 x 8 x 8-foot boards
  • 4 – .08 x 2 x 4-foot acrylic sheets
  • 2 – 15¾-inch heavy-duty adjustable hold-open pneumatic screen door closers
  • 1 – screen door pull
  • 4 – packages 2 x ½-inch mending braces
  • 2 – packages 1-inch corner braces
  • 3 – 2½ -inch narrow utility hinges
  • ¾-inch washer-head lath screws
  • 1¼-inch deck screws
  • 2-inch deck screws
  • 3-inch deck screws

List of Tools:

  • miter saw or circular saw*
  • drill/driver with #10 countersink bit
  • jigsaw with fine-tooth blade, heavy-duty utility knife, or plastic cutter (for cutting acrylic)
  • clamps
  • square
  • measuring tape

* or can have lumber pre-cut at home improvement store per dimensions in Parts List

Parts List:

Part Quantity Size
Inside End Stretcher 2 3/4 x 1 1/2 x 7 5/8
Outside End Stretcher 2 3/4 x 1 1/2 x 10 5/8
Top End Rails 2 3/4 x 1 1/2 x 49 1/4
Bottom End Rails 2 3/4 x 1 1/2 x 48 1/4
Short End Stiles 2 3/4 x 1 1/2 x 3 1/2
Long End Stiles 2 3/4 x 1 1/2 x 11 3/4
Front Legs 2 1 1/2 x 1 1/2 x 15 7/16
Back Legs 2 1 1/2 x 1 1/2 x 23 5/8
Front Rails 2 3/4 x 1 1/2 x 51 1/2
Front Stiles 2 3/4 x 3 1/2 x 3 5/16
Rear Rails 2 3/4 x 1 1/2 x 51 1/2
Rear Stiles 2 3/4 x 3 1/2 x 11 3/4
Rear Stretcher 1 3/4 x 1 1/2 x 11 3/4
Rear Legs 2 1 1/2 x 1 1/2 x 23 7/8
Hinge Board 1 3/4 x 1 1/2 x 54 3/4
Front Panel 1 5 3/4 x 48
Side Panels 2 14 3/4** x 48
Back Panel 1 14 1/2 x 48
Lid Rails 2 3/4 x 3 1/2 x 47 1/2
Lid Stiles 2 3/4 x 3 1/2 x 49
Lid Stretcher 1 13/4 x 3 1/2 x 42
Lid Panels 2 24 x 48
**at widest end – refer to cutting diagram for full dimensions

Cutting Diagram: Wood
simple cold frame: wood cutting diagram
Cutting Diagram: Acrylic
simple cold frame: acrylic cutting diagram

Use this slideshow for step-by-step directions for building a Raised Bed Cold Frame:

Note: Check the acrylic sheet panels periodically for gaps along the edges, as they may form during large swings of warm and cool temperatures. Add additional ¾-inch washer-head lath screws at these points as needed. If cracks form, use clear, small project construction adhesive or clear silicon sealant caulk to repair.

Finished Dimensions of Raised Bed Cold Frame:
Height: 24 7/8* inches
Width: 51 inches
Depth: 49 1/2 inches
*at highest point

Design by Chris Hill