The thirteen systems are the answer. This is the question they answer. Before you plan a litre of water or a kilogram of rice, there is the household itself — the particular people under one roof, in one place, with one set of strengths and needs — and everything the plan becomes is shaped by them. Water, food, power, medicine: none of it has a size until you say who it’s for.
So the plan doesn’t start with products. It starts with a portrait — drawn in three plain strokes.
Ages, and the needs that come with them — the frail, the growing, the ones with conditions. Named honestly, because a plan is only as true as who it thinks it’s feeding.
Land or apartment, roof and open ground, where your water comes from — the space decides what’s even possible in half the systems that follow.
The skills in the house, the kit on the shelf, the vehicle in the lane. A plan builds from where you are, not from zero.