How Houses Stay Warm
Houses don't warm residents automatically. Each residential building consumes one unit of fuel per resident per production cycle. Citizens automatically deliver fuel from the barn to homes that are running low — you don't manage this by hand.
Only when a house successfully burns fuel does it deliver warmth satisfaction to its residents. A house that runs out of fuel stops providing warmth, and in winter that leads to the warmth need dropping fast. If warmth hits zero, it starts draining health. People die from cold.
Domestic Fuels
Houses only accept domestic fuels: firewood and charcoal. Coal is an industrial fuel — it works in smelters and forges, and in the Great Hearth at high tiers — but homes cannot burn coal even if it's the only fuel in the barn.
| Fuel | Source | Efficiency |
|---|---|---|
| Firewood | Woodcutter's Lodge: 2 logs → 3 firewood | Base fuel — 1 unit = 1 unit of warmth |
| Charcoal | Charcoal Kiln: 4 wood → 3 charcoal | 1.5× efficient per unit — costs more wood to make, but each piece goes 50% further in a home |
The Fuel Chain
Don't confuse firewood with planks — both come from wood but serve different purposes. Firewood heats homes; planks build things. The Sawmill produces planks from logs; the Woodsplitter produces firewood. You need both.
Industrial Fuels
Industrial buildings — the Smelter, Blacksmith, Smokehouse, and others — use a separate fuel system. They can burn any fuel tagged as burnable, including coal. The player can set the priority order for industrial fuels from the Resource Panel (press F2), so you can decide whether your smelter burns charcoal or coal first.
Industrial fuel priority is independent of house fuel. Homes will never accidentally burn coal even if it's in the barn alongside firewood.
Winter Preparation
Warmth decay accelerates sharply in winter. A house that's marginally warm in autumn may be dangerously cold in winter with the same fuel supply. Build up firewood stocks in summer and autumn — do not wait for winter to discover you're short.
- Check barn stocks in autumn. Count your households and estimate how much fuel per cycle you need. A rough rule: one Woodcutter per 10 to 15 residents keeps a town warm through winter without charcoal; with charcoal, fewer woodcutters are needed.
- Hardy villagers need less fuel. A villager with the Hardy trait has warmth decay 25% slower, which meaningfully reduces personal fuel consumption in winter.
- Stone and Brick houses are more efficient. They provide double the warmth satisfaction per fuel cycle compared to wooden houses, meaning the same fuel stock goes twice as far for residents in a Stone House.
- The Great Hearth helps. Citizens within the Hearth's aura have warmth decay reduced — this stacks with clothing and home fuel. Place the Hearth centrally so as many homes as possible benefit from its warmth aura in winter.