The cheapest DIY compost bin is a plastic trash can with holes drilled in it: free if you already own one, done in under an hour. The sturdiest is a three-bay concrete block system that costs around $110 and takes a weekend. In between sit pallet bins, wire-mesh cylinders, and single-block bays, each trading cost against durability and capacity. Below are five designs drawn from university extension plans, with materials, dimensions, and approximate build costs, so you can match the bin to your yard and your Saturday.
Compare the five builds at a glance
| Build | Cost | Build time | Capacity | Best for |
|---|---|---|---|---|
| Trash can bin | $0–30 | Under 1 hour | 30–55 gallons (115–210 L) | Renters, small yards, first-timers |
| Wire-mesh cylinder | $40–75 | 1–2 hours | 8–10 bags of yard waste | Fast, movable, minimal tools |
| Pallet bin (3-sided) | $0–20 | 2–3 hours | ~27 cu ft (0.75 m³) | Free materials, larger volumes |
| Single concrete block bay | Under $60 | Half a day | 10–12 bags | Permanent, rodent-resistant setup |
| Three-bay concrete block system | Under $110 | Full weekend | 30–38 bags, turnable | Serious composters, active turning |
Costs are rough guides; prices vary by region, and reclaimed materials bring most builds close to free. The University of Missouri Extension distinguishes holding units, where material sits and decomposes, from turning units designed to be mixed regularly. The first four builds are holding units; the three-bay system is a true turning unit, trading labor for speed.
Build 1: The trash can bin (cheapest, fastest)
A 30- to 55-gallon (115–210 L) plastic or metal trash can with a locking lid becomes a closed compost bin with nothing but a drill. Drill four or five holes in the bottom, one centered and the rest spaced roughly 6 inches (15 cm) apart in a ring, for drainage. On the sides, drill a row of holes about 6 inches (15 cm) down from the rim, spaced 4–6 inches (10–15 cm) apart, then repeat rows every 6 inches down the can. Use a 1/2-inch (12 mm) bit; if the can is plastic, brace a scrap 2×4 inside while drilling so it doesn’t crack.
Set the finished can on a few bricks or blocks to lift it off the ground and let air and excess moisture escape from the bottom. Total cost is close to zero if you’re repurposing an old can, or under $30 for a new one.
Trade-off: a sealed can holds heat and moisture well but is hard to turn. Roll it on its side to tumble the contents, or mix with a long-handled aerator, since there’s no easy way to fork-turn material through a lid. Its small volume rarely gets hot, so keep diseased plants and seeding weeds out.
Build 2: The wire-mesh cylinder (fastest to set up outdoors)
This is the design many university extensions recommend as the entry point for anyone with outdoor space. Bend a 12½-foot (3.8 m) length of 36-inch (0.9 m) wide, 1/2-inch hardware cloth into a circle and fasten the overlapping ends with wire ties or hog rings: no posts, no digging. The resulting cylinder is roughly 4 feet (1.2 m) across and holds the equivalent of 8–10 bags of yard material, according to University of Wisconsin–Madison Extension. Budget $40–75 depending on the mesh; heavier galvanized hardware cloth costs more but resists sagging and rust better than thin chicken wire. The University of Missouri Extension notes that non-galvanized chicken wire can be used but won’t last as long.
To empty or turn it, lift the entire cylinder up and off the pile, set it down next to the now free-standing heap, and fork the material back in. This aerates the whole pile in one motion, which is the main advantage over a fixed bin. Missouri Extension also points out that a postless wire bin gives you access to finished compost at the bottom of the pile while the top is still decomposing.
What materials do you need for a pallet compost bin?
Three shipping pallets, six galvanized corner brackets, screws, and (optionally) a roll of chicken wire stapled to the inside to stop material falling through the slats. Standard pallets run about 48 × 40 inches (1.2 × 1 m), so three standing on edge and screwed together at the corners make a roughly 3 × 3 × 3-foot (0.9 m) open-topped bin, about the minimum volume for a pile that heats up well. A fourth pallet, hinged rather than screwed, makes a swinging front door for easier access.
Check the stamp before you build. Pallets marked “HT” were heat-treated; those marked “MB” were fumigated with methyl bromide, a pesticide, and are best kept away from anything destined for a food garden. Skip unmarked or stained pallets. If pallets are free (ask behind hardware stores and garden centers), total cost is under $20 for hardware. Expect a pallet bin to last a few seasons before the wood in contact with the damp pile softens.
Can you use pressure-treated lumber for a compost bin?
If you’re building from new lumber rather than pallets, this is the common question. According to University of Maine Cooperative Extension, older advice against treated wood dates from when it was made with chromated copper arsenate (CCA). That process was phased out for residential lumber in the early 2000s in favor of alkaline copper quaternary (ACQ), which UMaine says is not known to have the same toxicity or leaching concerns. Using it is a personal choice; hemlock or cedar are the untreated alternatives the extension suggests. Avoid old CCA-treated or painted wood entirely.
Build 4: The single concrete block bay
Stack standard concrete blocks three sides high, leaving 1/2-inch (12 mm) gaps between blocks in each course for airflow, and stagger the joints between layers the way you’d lay bricks, for stability. A one-bin unit needs about 38 blocks and, for extra rigidity, metal fence posts driven through the block cavities at the corners. University of Wisconsin Extension prices a one-bay block unit at under $60, holding roughly 10–12 bags of yard waste. Leave the front open, or stack blocks only to half height there, so you can fork material in and out without climbing over a wall.
Block bins are durable and need almost no maintenance, but they’re not portable, so choose the site carefully.
Build 5: The three-bay concrete block system
The same block-and-post method, extended to three side-by-side bays, is the design serious composters end up building because it turns a hobby into a working process. One bay takes fresh material, the second holds actively decomposing compost, and the third holds material that’s nearly finished; you shift material one bay over every few weeks instead of turning it in place. University of Wisconsin Extension specs this at 86 blocks, 4 half blocks, and 11 metal posts, for a total under $110, with a combined capacity of 30–38 bags. Because it’s built around active turning, it’s the fastest of the five to produce finished compost on a repeatable schedule.
How much space does a DIY compost bin actually need?
Plan for the bin footprint plus turning room. A single 3 × 3-foot (0.9 m) bin needs roughly 3 × 6 feet (0.9 × 1.8 m) of total clearance so you can fork material in and out without straddling the pile. Three-bay systems need proportionally more, closer to 10 × 4 feet (3 × 1.2 m), since you’re moving material sideways between bays rather than just turning in place. Site it where a hose reaches.
Do DIY compost bins need a solid bottom?
No, and most extension designs specifically avoid one. Composting depends on contact with soil organisms and drainage of excess moisture; a bin set directly on bare ground (not concrete or pavement) lets worms and microbes migrate in and lets liquid drain rather than pool. If you’re composting on a hard surface, add a shovelful of garden soil to the base to inoculate the pile before you start layering material.
If rats are a problem, the answer is a mesh floor rather than a solid one.
How do you rodent-proof a homemade compost bin?
Start with what goes in. Cornell Cooperative Extension advises against adding meat, fish, oils, cheese, or leftovers heavy in oil or seasoning, and against the feces of carnivorous pets, including cat litter. It also recommends keeping food scraps covered with a blanket of browns such as dried leaves, straw or shredded paper so they’re hidden from rodents.
Then close the gaps. Cornell suggests a bin with a solid top, bottom and sides apart from small vent holes, with those holes covered by hardware cloth or wire mesh. For an open-bottomed DIY build, the practical version is a sheet of galvanized 1/4- to 1/2-inch (6–12 mm) hardware cloth laid under the bin and fixed to its sides, which keeps drainage and worm access while stopping burrowers. A block bay with a mesh floor and a lid is the most rodent-resistant build here; an open pallet bin is the least.
Which DIY compost bin design is right for you?
Match the bin to constraints, not to what looks impressive.
- Renting, or might move within a year: a trash can or wire-mesh cylinder. Both are portable and cheap enough to leave behind. If you have no yard at all, see our guide to worm composting instead.
- Full-size yard, access to free pallets: a pallet bin gives volume for almost nothing. Build two side by side once the first fills.
- Permanent spot, plenty of yard waste: a block bay, expanding to three bays as volume grows.
- Rats in the neighborhood: a block bay or trash can bin with a mesh floor and a lid, and a strict no-meat, no-cooked-food rule.
Whatever you build, the bin only holds the pile; what you put in decides whether it works. For the day-to-day mechanics once a bin is built (the browns-to-greens ratio, how wet to keep it, and how often to turn), see our guide to starting composting, and check the composting do’s and don’ts before the first load goes in.