Nobody’s off-grid build falls apart because they picked the wrong flooring.
It falls apart because the solar array was sized off a guess, so the batteries are dead by 9pm in November. Or the water pump draws more surge than the inverter can deliver, so the lights flicker every time somebody washes their hands. Or the greywater setup that looked fine on YouTube turns out to be flatly illegal in that county, and now there’s a stop-work order taped to the door.
Utilities are where off-grid budgets go to die. They’re also the part most people plan last, after they’ve already committed to a shell, a trailer, or a piece of land — which is exactly backwards. Your utilities determine what shell you can use, how much roof you need, and in a lot of cases which counties will even let you live there.
This is the full checklist. Six systems, in the order you should actually decide them, with the specs and the questions that matter. Work top to bottom and you’ll catch the expensive mistakes while they’re still free to fix.
Want this as a printable PDF?
Get the free Off-Grid Tiny Home Utilities Checklist — power, water, waste, climate and permits, one page each.
How to use this checklist
Two rules before you start.
Rule one: decide in this order. Power → water → waste → climate → fuel → permits. Each one constrains the next. Your power budget decides whether you can run an electric water heater or need propane. Your waste choice decides whether you need a septic permit, which decides which land is viable. Jump around and you’ll redo work.
Rule two: write down real numbers, not ranges. “Some batteries” is not a plan. “Two 5.1 kWh LiFePO4 batteries, 48V, 10.2 kWh total, 8.2 kWh usable” is a plan. Every line below should end with a number you wrote down.
System 1 — Power
This is the one that eats budgets. Get it right and everything else gets easier.
1.1 — Calculate your actual daily load. Not your guess. List every device, its wattage, and how many hours a day it runs. Multiply, add it all up, and you have your daily watt-hours. Most tiny homes land somewhere between 2 and 8 kWh per day — propane cooking and heating puts you at the low end, an all-electric build with a mini-split and induction cooktop puts you at the high end.
Write down: ______ Wh/day
1.2 — Add system losses. Inverters, wiring, and charge controllers all cost you energy. Multiply your number by 1.3 to cover roughly 30% in real-world losses. If you skip this step, your system will be undersized by a third and you’ll never know why it underperforms.
Write down: ______ Wh/day adjusted
1.3 — Find your peak sun hours. This is not “hours of daylight.” It’s the equivalent hours of full-strength sun your location gets, averaged over the year. Most of the continental US falls between 4 and 6. The desert Southwest runs high, the Pacific Northwest runs low, and everywhere else is in between. Look yours up on NREL’s free PVWatts tool before you buy anything — and use the December figure if you plan to live there year-round, because that’s the month that will actually strand you.
Write down: ______ peak sun hours
1.4 — Size the array. Adjusted daily watt-hours ÷ peak sun hours = your minimum array in watts. Multiply by 1.25 for a cloudy-day buffer. Divide by your panel wattage and round up. There’s a full walkthrough with a worked example in our solar panel sizing guide.
Write down: ______ watts of panels, ______ panels
1.5 — Size the battery bank. Days of autonomy × adjusted daily use ÷ usable depth of discharge. Two days of autonomy is the practical minimum; three is comfortable. LiFePO4 batteries safely give you 80–90% of rated capacity; lead-acid gives you 50% and dies faster. The price gap has closed enough that lead-acid is rarely the right call anymore.
Write down: ______ kWh battery bank
1.6 — Pick the charge controller. MPPT, not PWM — MPPT harvests 20–30% more in cold or low light, and the price difference is small. Size it for your array’s amperage with headroom.
1.7 — Pick the inverter. Two numbers matter: continuous watts (what it runs all day) and surge watts (what it can deliver for a few seconds). Surge is what kills undersized inverters — well pumps, compressors, and power tools all spike hard on startup. Get a pure sine wave unit; modified sine wave will make some appliances buzz, run hot, or refuse to work.
1.8 — Plan the wire runs. Voltage drop is real and it’s invisible until things run badly. Keep DC runs short and thick. Fuse or breaker every circuit. If you take one shortcut in this entire build, do not let it be this one.
1.9 — Decide on a backup. Generator, shore-power hookup, or nothing? A small inverter generator plus a transfer setup buys you insurance for a bad week in December. A quality all-in-one solar generatorAs an Amazon Associate I earn from qualifying purchases. Some links on this page are affiliate links. If you click and make a purchase, I may earn a commission at no extra cost to you. is a reasonable bridge if you’re not ready to commit to a full system yet.
System 2 — Water
2.1 — Choose a source. Hauled water, rainwater catchment, a well, or a shared/community tap. Hauled is cheapest to start and the most annoying forever. Rainwater is cheap but climate-dependent and regulated in some states. A well is the most independent and by far the most expensive up front.
2.2 — Size your storage. Off-grid living tends to run 10–25 gallons per person per day, versus 80–100 on municipal water. Multiply by the number of days between refills, and add margin. Storage is cheap; running dry is not.
Write down: ______ gallons storage
2.3 — Plan for freeze. This one gets skipped constantly and it destroys plumbing. Tanks and lines need to be inside the heated envelope, buried below frost line, or heat-traced and insulated. Decide which, now.
2.4 — Pump and pressure. A 12V diaphragm pump with an accumulator tank is the standard tiny-home setup. Check the surge draw against your inverter (see 1.7). Aim for 40–50 PSI so showers feel like showers.
2.5 — Filtration. Sediment pre-filter → carbon → UV or ceramic if the source isn’t potable. Match the filtration to the source. Rainwater and well water need different treatment, and “it looks clean” is not a test result. Get the water tested.
2.6 — Hot water. Propane tankless is the off-grid default — instant, compact, and it doesn’t touch your battery bank. Electric tankless is a trap off-grid; the draw is enormous. A small electric tank heater can work if your solar array is genuinely oversized.
System 3 — Waste
This is the system that decides where you’re legally allowed to park.
3.1 — Pick a toilet. Composting (self-contained, no plumbing, no black tank), incinerating (no waste handling, but it eats propane or a big electrical load), or conventional flush into a septic or black tank. Composting is the off-grid standard for a reason.
3.2 — Plan greywater separately. Sinks and shower water is a different legal category than toilet waste in most jurisdictions. Some places allow simple subsurface irrigation; others require it to go to septic. Ask before you build.
3.3 — If you’re going septic, budget the whole thing. The tank is not the cost. A percolation test and a septic permit come first, and a failed perc test can disqualify a property entirely. Never buy land for a septic build without a perc test contingency in the contract.
3.4 — Ventilation. Every waste system needs a vent path. Composting toilets need a continuous low-draw fan. Plan the roof or wall penetration before your walls are closed up, not after.
System 4 — Climate
4.1 — Insulate for your actual climate zone. Look up your zone and the recommended R-values, then decide: spray foam (highest R per inch, seals air leaks, expensive, permanent), rigid boardAs an Amazon Associate I earn from qualifying purchases. Some links on this page are affiliate links. If you click and make a purchase, I may earn a commission at no extra cost to you. (good R, DIY-friendly, needs careful sealing at seams), or batts (cheapest, worst fit in tight spaces). In a metal shell like a shipping container, closed-cell spray foam is usually the right answer because it handles the condensation problem that batts don’t.
4.2 — Handle the vapor barrier. Warm moist inside air hitting a cold surface makes water inside your wall. In a metal-shelled build this is the single most common cause of hidden rot and mold. Get the vapor barrier placement right for your climate zone.
4.3 — Heat. Propane furnace, diesel heater, wood stove, or mini-split. Note the power draw of each — a diesel heater sips power, a mini-split does not, and a wood stove costs you nothing electrically but has real clearance and permit requirements.
4.4 — Cool. A 12V roof fan plus shade plus good insulation gets you surprisingly far. If you need a mini-split, go back to System 1 and re-run your load calculation, because it will change your answer.
4.5 — Ventilation. Tiny, well-sealed spaces build up moisture fast — cooking and breathing alone will do it. Plan cross-ventilation and an exhaust fan.
System 5 — Propane and fuel
5.1 — Total your propane load. Cooking, hot water, heat, and refrigeration if you’re going absorption. Add up the BTU/hr of everything.
5.2 — Size the tanks. Two 20lb or 30lb tanks with an automatic changeover regulator means you never run out mid-shower. Larger builds want a 100lb tank or a leased stationary tank.
5.3 — Safety, non-negotiable. Propane and CO detectors. Regulator with excess-flow protection. Tanks stored outside or in a sealed, vented compartment that drains to the exterior. Leak-test every joint.
System 6 — Permits and legal
Do this before you spend a dollar on materials.
6.1 — Zoning: Is a tiny home or container home a permitted dwelling on that parcel? Is there a minimum square footage? Many counties have one and it’s often larger than your build.
6.2 — Classification: Is your build an RV, a park model, an accessory dwelling unit, or a permanent structure? The answer changes which code applies and which inspections you need.
6.3 — Septic and well permits: Required before construction in most places, and they take time.
6.4 — Solar and electrical inspection: Some jurisdictions require permitted, inspected electrical even off-grid.
6.5 — Full-time occupancy: A lot of places will let you build a tiny home but not let you live in it full time. Ask that question specifically.
6.6 — Get it in writing. A friendly phone call with a planning department clerk is not a permit. Email, and keep the reply.
The order to do it in
- Confirm you’re legally allowed to live there — before anything else
- Calculate your power load
- Choose water source and waste system (these drive your permits)
- Design the envelope and insulation for your climate
- Size solar, batteries, and inverter against the real load
- Build the electrical properly — fuses, wire gauge, disconnects
- Test every system before you close up a single wall
FAQ
How much do off-grid utilities cost for a tiny home?
Realistically $8,000 to $25,000 for the full stack — solar, water, waste, and climate — depending on how much you DIY and whether you need a well or septic. Our full 2026 cost breakdown itemizes every line.
Can you live off-grid in a shipping container home?
Yes, and the utilities are largely the same as any tiny home. The differences are insulation (a metal shell needs closed-cell spray foam or very careful rigid board work to control condensation) and roof penetrations for vents and solar mounts, which need proper sealing.
What’s the most common off-grid utility mistake?
Undersizing the solar array by skipping the system-loss multiplier. Second most common: not checking inverter surge capacity against the water pump.
Do I need permits to go off-grid?
Almost always, for at least septic and often for electrical and the structure itself. Off-grid does not mean off-code. Confirm with the county planning department in writing before you build.
Get the printable version — free
The full checklist as a PDF, including a blank load worksheet you can fill in on site.