2. Build your own compost box

The following instructions describe how to make a wooden compost box (size: 75x75x75cm), consisting of identical interlocking sections, which are stacked one on top of the other. As the compost decreases in volume, the top sections of the box can be taken off and used to start building up a new container. Make a few extra sections and you will have a very flexible composting system. Keep the rain out with a wooden lid or square of old carpet or polythene.  

Materials and equipment needed:

To make ten sections of the box you will need:

  • 30 m of wooden boards (e.g. reclaimed timber such as floorboards or pallets), approx 7.5cm wide and a minimum 1.5cm thick
  • 2.2m of 5cm x 5cm timber
  • 220 x 3.6cm long screws, size number 8
  • Rulers, screwdrivers, drills (could use hand drills), and saws

Build your own Compost box: Tools you will need

Building each section of the box

1) Cut 2 boards, each 75cm long.

2) Cut 2 boards, each 72cm long.

3) Cut 4 lengths of 5.5cm from the 5cm x 5cm timber. These will make the corner blocks.


Build your own compost box: Sawing wood

4) Take one of the 72cm shorter boards and place it on one of the corner blocks. The ends of the board should be flush with the block. The block should be offset so that it projects 2cm below the edge of the board (as shown in the diagram below).

5) Hold the board in position on the blocks. Drill 2 holes at one end of the board, through the board and into the block below. Fasten with 2 screws (see diagram below).

Build your own Compost box: Joining boards

 6) Repeat steps 4 and 5 at the other end of the board (see diagram below).

Build your own Compost box: Completed side

7) Now repeat steps 4-6 with the second shorter (72cm) board. For the next stage you may need someone to help hold the pieces while you fix them together.

8) Stand the 2 shorter boards on their ends, approximately 75cm apart, with the protruding ends of the blocks away from you. Place a 75cm board on top of these vertical boards to form the third side of the section. Ensure that the ends of the longer board are flush with the edges of the vertical boards.

9) Drill and screw each end of the 75cm board, as in step 5 (see diagram below).

Build your own Compost box: Joining sides

10) Turn the section over so that the unfinished side is uppermost. Place the second 75cm board across between the shorter boards as before. Position squarely and drill and screw as in step 9.

Build your own compost box: Finished frame

11) Continue making sections until you have as many as you want. You need to weatherproof any timber that has not been treated to make it last.