Let's take a closer look at the features of the compost pen that Charles designed and built. It's a simple structure, but its features improve the flow of collecting, turning, and harvesting compost. Charles also minimized the cost of building the pen by using salvaged and free materials.
1. Drain tile is set into a foundation of compacted dirt, which slopes toward a drainage trench at the rear of the pen. The trench is filled with cobblestones, which were collected from the yard.
2. Charles had intended to fill the bottom of the pen with gravel, but changed his mind when a neighbor offered a supply of wood chips. Wood chips are appropriate for this application because they absorb moisture and encourage compost-benefical insects. Wood chips are also preferable to gravel because some of the base layer will inevitably be integrated into the compost during turning. A layer of wood chips in front of the pen provides an area to stand while adding to and turning the compost.
3. The wood used in the frame was left over from the house construction several years ago. By saving wood and other materials, the homeowners have a collection of usable materials for many projects, and avoided contributing to the huge amount of waste accumulated by residential construction. According to the National Association of Homebuilders' Research Center, construction of the average 2000 sq. ft. home generates 8000 lb. (50 cubic yards) of material waste, 3000 lb. (11 cubic yards) of which is wood.
4. Charles's original plan called for 1 cm square-grid "hardware cloth" to line the pen. However, lighter-gauge chicken wire was a quarter of the price of the hardware cloth. Doubling the chicken wire created a 1.5 cm grid at half the cost.
As you can see, Charles's building techniques include using salvaged materials, working with materials provided by the site, and designing creatively. Whether you live in a rural or urban environment, opportunities exist to reduce the cost and resources used for your project.