Most homestead builds fail before the first cut. Someone buys a 400W panel, a tank, or a pile of 2x4s, then tries to invent the job around the pile.

Write one sentence first: this system must provide __ for , during __ conditions. Then write what it must not do. A shed lighting system that must not run a heater. Irrigation that must not be drinking water. A coop that is not a vet clinic.

That one page is the whole design. Cut lists, calculators, and CAD come after.

If a mistake can cause fire, collapse, bad water, or animal suffering, do not use a guess as the final plan. Measure twice. Hire the electrician for utility/AC work. Your inspector still wins.