If you've always wanted to build a compost pile but lack of space is a real issue, you should consider using a stacking bin. A stacking bin is composed of three smaller containers with refuse piled inside. To turn the bin, you unstack each container and shuffle the contents from one container to the other. A stacking bin helps to effectively reduce the size of compost for smaller spaces by directing the pile's mass upward instead of outward.
Cut the 16-inch-wide galvanized hardware cloth into 12 sections measuring 30 inches long.
Cut the 30-inch-wide hardware cloth into three squares that are 30 square inches.
Lay four 2-by-2 boards that are 30 inches long into a square with abutting corners. Place an L-shaped bracket on the outer edge of each corner. Attach the L-bracket to the wood with wood screws to create six wooden squares that will be the tops and bottoms of your box frames. Separate these wooden squares into pairs. Each pair will form the top and bottom frame for a box.
Lay each pair of 30-inch wooden squares on an outer edge so that each square is 16 inches away from its partner. Place two of the 16-inch 2-by-2s into the inner corners of each wooden square to form two corner walls of a box. Affix the wooden squares to the 2-by-2s with wood screws. Turn the wooden structure over so that the side with the 2-by-2s is facing upward. Slide the remaining 2-by-2s into the empty corners of the bottom of the structure and attach them with wood screws to complete the box frame.
Place the 30-inch-square hardware cloth over the bottom of each box frame. Staple the cloth to the wooden frame with the staple gun.
Place the 16-inch-wide and 30-inch-long hardware cloth against the sides of the box frame. Staple the cloth to the sides of the frame. You now have three separate compost bins that will stack.