Your storage is a junk drawer the size of a space station. I know because I built one.
After 80 hours of dumping iron plates next to copper wire because the nearest chest was full, I finally sat down and designed a storage network that actually works. Here is the three-zone layout I use on every save now.
The 3-Zone Storage Layout
Stop building one giant warehouse. Split your storage into three zones connected by a single sorting bus or drone port.
Zone 1 - Drops (Receiving): Every incoming belt or cargo drone dumps here. Raw ore, loot, deconstructed parts, manual dump runs – it all lands in a row of buffer chests. Do not sort here. Just accept everything. Filter inserters pull items off mixed belts and into the correct buffer chest by type. This zone should be the first thing you build and the first thing you forget about.
Zone 2 - Sort (Processing): This is the brains of the operation. Each buffer chest from Zone 1 feeds onto a central sorting belt loop (or through a dedicated cargo drone hub). Filter inserters, stack inserters, and priority splitters route items to their designated warehouse or silo in Zone 3. The sorting loop runs one lap, and by the end every item type has a home.
Zone 3 - Store (Long-term): Warehouses and cargo silos live here. No sorting logic, just pure storage. Pull from here for your production lines. This zone is where I use auto-sort enabled warehouses (available mid-game) to keep stacks organized internally.
The three zones should be physically separated by at least a few tile gaps to prevent belt cross-contamination. Trust me on this.
Storage Type Reference
Here is every storage container you will encounter and what I use each for:
| Type | Stack Size | Auto-Sort | Best For | Throughput |
|---|---|---|---|---|
| Basic Chest | 16 slots | No | Early game, overflow catch | Low |
| Buffer Chest | 24 slots | No | Zone 1 receiving, drone depot | Medium |
| Warehouse | 48 slots | Yes (T2+) | Zone 3 bulk storage | High |
| Cargo Silo | 64 slots | Yes | Single-item mass storage | Very High |
Basic chests are your first-week friend and your first-month bottleneck. Upgrade to warehouses as soon as you unlock them. Cargo silos are endgame for high-volume items like iron plates, copper ingots, and circuit boards. Buffer chests are the unsung hero – they link belt and drone networks and give you that extra slot wiggle room.
Pro tip: overflow management. Every buffer chest in Zone 1 should have its last slot reserved (right-click the slot) for overflow detection. When that slot fills, send a signal to your alert system or dump excess into an overflow warehouse. Otherwise a single backed-up iron plate line will stall your entire sorting loop. Combined buffer strategies are covered in our Buffer Storage Strategy Guide.
The Day I Lost 500 Iron Plates
Here is the exact scenario that forced me to design this system.
I had one unloader dumping mixed scrap from a mining outpost onto a single belt. Iron plates, copper ore, stone, coal – all tangled together. I let it feed directly into a single row of chests. One chest filled with coal. The belt backed up. The station’s iron plate supply starved. By the time I noticed, my construction drone hub had chewed through 500 plates building conveyor segments that were going nowhere.
The fix: a two-tile buffer gap with filter inserters on the receiving belt pair. Each filter inserter targets one item type. They pull from the mixed belt in priority order (iron first, always) and drop into labeled buffer chests. The leftover items loop back for another pass. The belt never stops.
This is also where inventory pairing becomes relevant – once items reach Zone 3, pairing warehouses with production requesters keeps your factory fed automatically.
Verdict: Three-zone storage is not optional past the early game. A single warehouse room with mixed belts will fail under load. The upfront cost of sorting infrastructure (extra belts, filter inserters, and dedicated chests) pays for itself the first time your iron plate supply does not brown out. Build the zones. Label everything. Never let a mixed belt touch your main storage.
Cargo Drone Integration
Once you unlock cargo drones, your storage network connects to the whole station. Zone 1 buffer chests with drone port access can both accept and distribute items. Set your Zone 2 sorting loop to pull from drone drop-off pads using priority splitters. Zone 3 warehouses become drone supply depots – configure each warehouse as a “provide” node so drones auto-restock production lines.
One trap: drones can bypass your sorting logic if you give them direct access to Zone 3. Always funnel drone deliveries through Zone 1 first. Let your sorted output from Zone 2 feed Zone 3, not the other way around.
Quick Reference: Building Your First Sorting Loop
- Place a ring of express belts around your Zone 2 area
- Drop filter inserters at each Zone 1 buffer chest, pointing into the ring
- Set each inserter to grab exactly one item type
- Ring the loop with warehouses in Zone 3 with filter inserters pulling off the belt
- Resume the loop – unclaimed items circle back
- Place one overflow chest at the loop exit to catch anything that does not match. For a deeper approach to handling excess items, our Overflow Sink Management Guide covers priority routing and sink-burner configurations.
This takes about 20 minutes to build and will handle all your storage needs through mid-game. When it backs up, build a second loop.