Land, building, and a house that grows
The village sells parcels along its lanes, and the ones nearer the green cost more. A family that buys one marks out a site the yard raises, walls first and roof at thirty timber and five stone, from hovel to house to second storey to manor.
Households outnumber houses, on purpose
A family doubled up under someone else's roof is the usual buyer, and that pressure is what makes the land market move. The yard builds when families are doubled up, mends ruins first, and raises the houses people have paid to improve.
The rich buy a second parcel because they can. A household in debt sells its spare land back. Wealth shows on the map as space.
A house is so many doors, not so much floor
Every house holds a number of dwellings: one for a hovel or a house, two for a second storey, three for a manor, and as many as it was built with for a row or a tenement. Five souls to a dwelling before it is crowded, and crowding costs mood, sleep and health.
That makes upgrading a house an act of housing rather than of vanity: the day the yard finishes a second storey, the worst-housed family in the village moves into it. And when the lanes near the green are full the village stops building out and starts building up, which is the only answer to a yard of seven carpenters that cannot raise nine cottages a year.
A shortage is measured in households against doors, never in people against floor space. The second measure said the valley was housed while fifteen families were doubled up, because it counted the spare room in a rich family's new storey as housing for a family who were not in it.
A tier-0 building is not a ruin
This is the sharpest edge in the village code. A newly marked-out plot is a Building at tier 0, with walls not yet up. If the yard's ruin filter includes it, the yard repairs sites forever and finishes none: seventy-four sites, zero finished houses, found by running it rather than by reading it.
yardTask excludes tier 0 from the ruin filter and must keep doing so. It is a good example of a bug that is invisible in review and obvious in a ledger.
Fire
A spark from a crowded hearth, or the crowd's choice, spreads through thatch and is fought with buckets by whoever is near. Fire is one of the few events that can undo an hour of a family's fortunes in a minute, which is what makes the yard's queue a tense object.
The bridge
Either reeve, or either master carpenter, can order the bridge, and both yards can work on it. When it stands, people cross on Sundays for the other inn and carters take what is plentiful on one bank to where it is short on the other.
That ledger is the seed of trade, and of war. Every person, building and stockpile carries a villageId, and a village already has relations, militia and a tradeLedger, so a second bank is an addition and not a rewrite.
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A closed medieval economy, in real time
Two villages of about 220 people each run a complete production chain, field to mill to bakehouse and pasture to butcher, with floating market prices, daily wages, household purses, tax, tithe, and a winter every twelve days.
Households, marriage, birth and death
The household is the unit. Everyone has parents, children, a surname, a purse and a larder; people court, marry, take a house, have twins or triplets, feud, sicken, are jailed, die, and are buried in the churchyard their kin visit on Sundays.
The crowd's hand
Every ninety seconds watchers are offered three things that could happen next: a fire at a named house, twins for a woman who is carrying, wolves, damp in the grain, soft rain, a pedlar, a feast. The one they pick happens.
The fever, and how it gets about
A fever is caught rather than rolled: it passes between people in the same place in the same hour, harder under a roof and harder again in a crowded one. Strangers carry it up the road, and a reeve can shut the square against it.