Steps // How to Build a Cold Frame
1 ×

#### Overview for Building a Cold Frame

Step One // How to Build a Cold Frame

## Overview for Building a Cold Frame

Illustration by Gregory Nemec

Project timeline:

Friday: Size and cut the pieces.

Saturday: Assemble the frame and attach the window.

Sunday: Prepare the site and install the cold frame.

2 ×

#### Measure the Window

Step Two // How to Build a Cold Frame

## Measure the Window

Photo by Matthew Benson

The window lid will be hinged along its length and sloped to let in maximum sunlight. Measure the window's long edge to get the length for the front piece and the two back pieces. Sandwiched between, the sides taper back to front, which means they'll be shorter than the window is wide. To determine their length without resorting to geometry, stage one end of the frame two-dimensionally: Butt two boards end-to-end, then pair up a third parallel with one of them to mimic the height of the back. Slide the single board away from the pair and open a gap approximately as wide as the window. Then stand the window on end, angling it from the "back" to the "front," and adjust the gap until the window just overlaps the boards at either side, as shown. Now measure the gap to determine the length of each side piece.

3 ×

#### Cut the Pieces to Length

Step Three // How to Build a Cold Frame

## Cut the Pieces to Length

Photo by Matthew Benson

Using a miter saw, cut to length the front board, two back boards, and four side boards.

4 ×

#### Mark the Angle

Step Four // How to Build a Cold Frame

## Mark the Angle

Photo by Matthew Benson

The top board of each side needs to be tapered. To get that angle, run a straightedge diagonally from the top corner of one end of a board to the bottom corner of the other end, and mark the line, as shown.

5 ×

#### Cut the Angle

Step Five // How to Build a Cold Frame

## Cut the Angle

Photo by Matthew Benson

Clamp the board to the work surface and use a jigsaw to cut the angle. Now you have your two tapered pieces.

6 ×

#### Mark and Cut the Tall Battens

Step Six // How to Build a Cold Frame

## Mark and Cut the Tall Battens

Photo by Matthew Benson

The tops of all the frame's battens must follow the side taper so that the lid can close. For the tall ones at the rear of the sides, cheat them in using a board on edge to block out space for a back batten. With the tall batten flush at the bottom, transfer the taper angle to the board, as shown. Using the miter saw, cut that angle. Repeat.

7 ×

#### Mark and Cut the Short Battens

Step Seven // How to Build a Cold Frame

## Mark and Cut the Short Battens

Photo by Matthew Benson

Cut two more battens at the same angle. Since they taper down to a single board in front, you can mark each batten's height with the width of a board, as shown. Cut both battens.

8 ×

#### Glue the Battens

Step Eight // How to Build a Cold Frame

## Glue the Battens

Photo by Matthew Benson

Using construction adhesive, glue the battens in place, making sure to leave space for the back batten.

9 ×

#### Screw the Battens

Step Nine // How to Build a Cold Frame

## Screw the Battens

Photo by Matthew Benson

Using a drill/driver and four 1⅝-inch screws, secure each batten.

10 ×

#### Cut the Back Battens

Step Ten // How to Build a Cold Frame

## Cut the Back Battens

Photo by Matthew Benson

The battens binding the back boards together must be beveled at the top to match the side taper. Using the miter saw, cut a scrap block to the angle of the taper. Then loosen the jigsaw footplate, hold it flat against the side edge, tilt the blade to match the taper, and set the saw, as shown. Cut the bevel. Now cut the batten to length so that it's flush with the frame height from the peak of the bevel to the bottom of the board. Repeat for a second batten.

Tip: If the plants you want to grow are taller than what would fit in this frame, you can make your version higher by adding a plank to each side and sizing the battens accordingly.

11 ×

#### Position the Back Battens

Step Eleven // How to Build a Cold Frame

## Position the Back Battens

Photo by Matthew Benson

To allow room to sandwich the sides between the front and back of the frame, set a board on edge as a spacer, flush with one end of the back. Position the batten against the spacer, flush at the top and bottom.

12 ×

#### Glue and Screw the Back Battens

Step Twelve // How to Build a Cold Frame

## Glue and Screw the Back Battens

Photo by Matthew Benson

Using a caulk gun and construction adhesive, glue each batten in place. Then sink four 1⅝-inch screws through the battens and into the back boards.

13 ×

#### Screw the Four Sides Together

Step Thirteen // How to Build a Cold Frame

## Screw the Four Sides Together

Photo by Matthew Benson

Butt a side assembly into the back to form a corner. Drill a countersink, and drive two 2½-inch screws through the side and into the edge of the back batten, as shown. Repeat for the second side. Attach the front board with two screws through its ends and into the edge of the short battens.

14 ×

#### Attach the Hinges

Step Fourteen // How to Build a Cold Frame

## Attach the Hinges

Photo by Matthew Benson

Screw removable-pin hinges into the battens on the inside corners. This lets you remove the assembly screws, take out the pins, and easily break down the frame for storage.

15 ×

#### Attach the Hinges

Step Fifteen // How to Build a Cold Frame

## Attach the Hinges

Photo by Matthew Benson

Using a garden rake, loosen and turn the soil, creating a level bed for the frame.

16 ×

#### Install the Pavers

Step Sixteen // How to Build a Cold Frame

## Install the Pavers

Photo by Matthew Benson

Set the frame in place and lift each side to slip pavers beneath it to create a sturdy foundation. The bottom edge of the frame should rest on the center line of the pavers, as shown.

17 ×

#### Attach the Lid

Step Seventeen // How to Build a Cold Frame

## Attach the Lid

Photo by Matthew Benson

Refurbish the window as necessary, coat it with an exterior paint, and let it dry. Set the window in place so that its edges are flush with the frame. Screw two strap hinges to the back edge of the window and the back of the frame, as shown.

18 ×

#### Install the Handle

Step Eighteen // How to Build a Cold Frame

## Install the Handle

Photo by Matthew Benson

Refurbish the window as necessary, coat it with an exterior paint, and let it dry. Set the window in place so that its edges are flush with the frame. Screw two strap hinges to the back edge of the window and the back of the frame, as shown.

19 ×

#### Cut the Vent Rods

Step Nineteen // How to Build a Cold Frame

## Cut the Vent Rods

Photo by Matthew Benson

Cut several pieces of ½-inch dowel at varying lengths. They can be used to prop up the window for ventilation or to keep plants from overheating on sunny days. This also prevents moisture buildup.

20 ×

#### Position the Frame

Step Twenty // How to Build a Cold Frame

## Position the Frame

Photo by Matthew Benson

Set the assembled cold frame on its paver foundation. With the lid propped up, use a garden spade to dig holes for your seedlings or plants. Then watch them flourish regardless of outside temperatures.