Factorio Mall Guide — How to Build a Factory That Builds Your Factory

Complete mall guide for Factorio: automate belts, inserters, assemblers, and all building materials. Step-by-step mall layout with exact ratios and belt configurations.

Every Factorio player hits the same wall around hour 10: you need 200 blue inserters to upgrade your green circuit line, but you've been hand-crafting them one by one since the start. The fix isn't more iron plates — it's a mall. One centralized production line that churns out belts, inserters, assemblers, and everything else your expanding factory craves.

TL;DR: A mall is not a science build — it's a production hub that makes building materials on demand. Start with 4 core machines (belts, inserters, assemblers, power poles) fed from a single iron bus. Add steel and green circuits as a second phase. One belt of iron plates feeds the entire early-game mall.
Factorio mall layout showing belt, inserter, assembler, and power pole production lines fed from a shared iron belt

Why Your Factory Needs a Mall

In Factorio, there are two kinds of factories: the one that makes science, and the one that makes the things that build the science factory. New players focus on the first and neglect the second. The result? Every new outpost requires a trip back to base to hand-craft 300 belts and 80 inserters before you can even lay the first rail.

A mall solves this by producing every construction item you need, in one place, continuously. It doesn't need to be fast — just consistent. One belt assembler running non-stop will fill a chest faster than you can use them, as long as the chest has room.

The table below shows what a typical early mall needs per minute. These numbers are surprisingly small:

ItemBuild machinesIron/minOther inputs/minChest target
Yellow belt11.51 steel chest
Yellow underground15.05 gears1/2 chest
Yellow splitter13.03 gears1/2 chest
Burner inserter11.51/2 chest
Assembly machine 115.03 gears, 3 circuits1/4 chest
Wooden power pole11 wood1 steel chest
Pipe11.01 chest

This entire mall consumes roughly 1 full yellow belt of iron (15/sec) at peak — a tiny fraction of what one furnace column produces.

Building the Mall Module by Module

The mall is modular. Build each module in sequence and extend as you unlock new materials.

Phase 1: Iron-Only Core (5 minutes)

Run one belt of iron plates along the back of your mall area. This single belt feeds everything.

Place assemblers along the belt in this order, each outputting into a steel chest:

1. Yellow belt assembler (×1). Pulls iron from the main belt. One assembler fills a chest of 2400 belts fast. Use a fast inserter into the chest so it keeps up.

2. Burner inserter assembler (×1). Same setup — iron in, burner inserter out. You'll use these for boiler-fed furnace columns until you get electric inserters.

3. Pipe assembler (×1). One iron plate = one pipe. Iron efficient, and you need pipes for everything: oil, fluids, steam.

4. Wooden power pole assembler (×1). Feeds from a separate wood chest (refill manually from tree-clearing runs). One chest of poles lasts through early mid-game.

Don't put gear and belt assemblers on the same iron lane. A belt assembler makes 1 belt from 1 iron plate, but the gear assembler chews through plates at 2/sec. If they share a half-belt, the gear assembler starves the belt maker. Use a splitter to dedicate one lane to gears and one to direct iron plate consumption.

Phase 2: Gear-Dependent Items

Once your core is running, add a gear-making sub-section. Place 2 assembling machine 1s making iron gears onto a dedicated half-belt running parallel to the main iron belt.

5. Yellow underground belt assembler (×1). Takes 5 iron plates + 5 gears per pair. Place it above the gear belt so inserters can grab both inputs.

6. Yellow splitter assembler (×1). 3 plates + 3 gears per splitter. Same dual-input setup as undergrounds.

7. Assembly machine 1 assembler (×1). Takes 5 plates + 3 gears + 9 green circuits. Green circuits need their own supply line — phase 3.

Phase 3: Green Circuit Integration

This is when your mall starts earning its keep. Run a single belt of green circuits parallel to the iron and gear belts.

8. Electric inserter assembler (×1). If you have green circuits, there's no reason to make burner inserters anymore. Electric inserters use the same recipe but skip the iron plate cost entirely.

9. Medium power pole assembler (×1). 2 steel + 4 circuits. Steel needs its own supply line, which means a dedicated steel furnace column or at minimum a steel chest you refill.

10. Fast belt assembler (×1). 1 gear + 1 circuit per belt. Upgrade your mall itself to fast belts once this is running — the increased throughput means your chests fill faster.

Where the Mall Typically Breaks

Insufficient gear throughput. Two gear assemblers running on a shared belt run out of iron fast. The solution isn't more gear assemblers — it's a dedicated iron belt for gears. One full belt of iron plates feeding exclusively into gears supports 4-5 gear assemblers, which is enough for a full mall.

The steel bottleneck. Steel is the first real test of your mall design. You need steel for fast belts, medium poles, and electric furnaces. The best solution is a dedicated steel smelter that feeds a half-belt directly into the mall. Don't share your main iron bus steel production with the mall supply — they compete and both starve.

Over-complicating the layout. I've seen mall designs that use circuit conditions, buffer chests, and logic combinators to balance production. They're beautiful and completely unnecessary. A regular chest with one fast inserter pulling from one assembler is enough. If the chest fills up, the assembler stops. That's your circuit control.

Scaling Your Mall to Mid-Game

As you unlock blue science, your mall needs two additions:

  • Red belts upgrade. Replace yellow belt assembler input with iron gears + circuits. Keep the yellow assembler as a backup for areas that don't need fast belts.
  • Steel furnace mall module. Add a dedicated sub-factory for electric furnaces, chemical plants, and pump jacks. These items are expensive to hand-craft but cheap to automate.
  • Rail components. Once trains unlock, add rail, rail signal, and train stop production. One assembler for each, outputting into chests, fed from the same iron/steel/gear bus.

The rule of thumb: if you've hand-crafted something three times, it deserves an assembler in the mall.


Community Verification & Resources

Related: Main Bus Guide | Smelting Ratios | Your First Factory