Before it keeps anyone warm, shelter is simply the place everything else happens — where the food is stored, the water banked, the people live and sleep. So it has two big jobs, and most people only picture the second. It has to hold the right space — for the people, their stores, and the kit the other systems bring — and it has to keep all of that warm, dry, secure and standing through a hard year.
And here is the part people miss: the profile of your space is Shelter's to capture — and it flows into everything else. Whether you can dig a sump, grow food, park a vehicle, catch rain or mount solar; whether the ground floor needs hardening; how much room the people and the stores get — these are answered here, then handed to Water, Power, Food, Sanitation, Transport and Security to build on. Get the space right and half the other decisions make themselves.
What your home physically is quietly decides what's even possible in every other system. This comes first.
The envelope that keeps the weather out and the warmth in — and mends fast when a storm breaks it.
What the plan parks on your structure, whether it can take the weight, and how safely your stores are held.