A tiny house without utilities is a very expensive shed. Power, water, and sewage are the three lifelines that make it a home, and each one offers the same fork in the road: the simple grid-tied path or the independent off-grid one.
This guide walks all three systems with sizing rules and real costs: grid, solar-plus-battery, and hybrid power; municipal, well, rainwater, and hauled water; sewer, septic, composting toilets, and greywater. Start with the load audit method inside and you will buy exactly the system you need, neither starved nor oversized.
The Three Lifelines
Power, water, and sewage are the three systems that make a tiny house a home rather than a shed. Each has a grid-tied path (simple, familiar, location-dependent) and an off-grid path (independent, engineered, liberating). This guide covers both, with sizing rules and cost ranges for each.
1. Power Option A: Grid Connection
The simplest path: connect to the electrical grid like any house. Process: apply to the utility, pay the connection fee ($1,000–5,000 depending on distance to the nearest pole — distance is the cost driver), install a meter base and panel, pass inspection. Ongoing: standard residential rates; a tiny house’s electrical load is small (expect $30–80/month). Grid power is the right choice when: the connection is affordable (existing nearby infrastructure), you want air conditioning without generator noise, or local code requires grid connection for the permit. The downside: monthly bills forever, and no power in outages without backup.
2. Power Option B: Solar + Battery Off-Grid
The independent path: a solar array sized to the tiny house’s modest loads. Typical tiny house system: 2–5 kW of panels ($4,000–10,000 installed), 10–20 kWh of lithium battery storage ($5,000–12,000), a hybrid inverter/charger ($2,000–4,000), and a backup generator ($1,000–3,000) for the cloudy weeks. Total: $12,000–29,000 for full off-grid power. Sizing rule: audit your loads first (a Kill-A-Watt meter, $30, measures everything for a week); size the battery for 2–3 days of autonomy; size the array to recharge fully on an average winter day (not summer — winter is the constraint).
Load discipline: the tiny house solar advantage is small loads. Heat water and cook with propane, heat space with wood or a mini-split, and the electrical load stays manageable. Electric resistance heating on solar is the classic budget-killer.
3. Power Option C: The Hybrid
Grid connection plus a small solar/battery system for backup and bill reduction: a 2–3 kW array with 5–10 kWh of battery ($8,000–15,000) covers outages and shaves peak usage. The hybrid is increasingly the sweet spot: grid reliability, solar resilience, and the system pays for itself in 7–12 years at typical rates. With net metering (where available), the grid becomes your seasonal battery.
4. Water Option A: Municipal / Well Connection
Grid-tied water: municipal hookup (connection fees $1,000–5,000; monthly $20–60) or a drilled well ($5,000–15,000 for the well, pump, and pressure tank; then nearly free water). Well water needs testing (annual basic panel, $100–200) and possibly treatment (sediment filter, softener, or UV — $500–2,000). A well is the tiny house owner’s favorite utility: one capital cost, decades of water, no monthly bill.
5. Water Option B: Rainwater and Hauling
Off-grid water: rainwater catchment (roof collection, first-flush diverter, cistern storage, filtration + UV purification — $3,000–8,000 for a complete potable system) or water hauling (a 300–500 gallon tank filled at a municipal fill station, $0.01–0.05/gallon; a couple uses 40–60 gallons/day with conservation). Rainwater legality varies (Colorado restricted it until recently; most states allow it; check local rules). The tiny house water advantage: conservation is easy at small scale (low-flow everything, navy showers), cutting usage to a third of a conventional home.
Filtration chain: sediment filter → carbon filter → UV sterilizer is the standard potable chain. Test the output annually; filters are cheap, illness is not.
6. Sewage Option A: Sewer / Septic Connection
Conventional: municipal sewer hookup ($2,000–8,000 connection) or a septic system ($8,000–25,000 installed — the single most expensive utility, driven by soil conditions and local requirements). Septic for a tiny house: the system is sized to bedrooms, so a 1-bedroom tiny house needs the smallest (cheapest) permitted system. Perc test first ($500–1,500) — the soil determines everything. Failed perc means engineered systems ($20,000+) or no septic at all.
7. Sewage Option B: Composting Toilets and Greywater
The off-grid path: a composting toilet ($1,000–2,500 for a quality unit) handles blackwater; greywater (sinks, shower) goes to a mulch basin, constructed wetland, or branched-drain system ($500–3,000). Combined cost: under $5,000 vs $8,000–25,000 for septic. Legality varies enormously: some jurisdictions explicitly permit composting toilets, some prohibit them, many are silent (the gray zone — get written approval before building). Greywater rules are similarly patchy. This is the highest-variance utility decision; research your specific jurisdiction before committing.
Composting reality: quality units are odorless when used correctly (the fan and the cover material do the work). Cheap units are not. Buy the good one.
8. Internet and Communications
The fourth utility: Starlink ($120/month, works anywhere with sky view — the rural tiny house standard), cellular hotspots ($50–100/month; verify coverage at your specific site before committing), or fixed wireless/cable where available. Redundancy matters for remote workers: Starlink + a cellular backup covers nearly every outage scenario. Budget $100–200/month for robust rural connectivity.
9. Sizing the Whole System: The Load Audit
Before buying anything: audit. Electrical: measure every load for a week (or estimate from nameplates) and build the daily kWh budget. Water: track usage for a week (or estimate: 20–30 gallons/person/day with conservation). Sewage: match the toilet/greywater choice to the water usage (composting + greywater needs no septic sizing). The audit prevents the two classic errors: the oversized system (money wasted) and the undersized one (the generator running at midnight in January).
10. Costs Compared: Three Utility Packages
- Full grid-tied: $5,000–15,000 connection costs; $100–250/month ongoing. Simplest, least resilient.
- Full off-grid: $20,000–45,000 capital (solar, well or rainwater, composting + greywater); $100–200/month (internet, propane, maintenance). Independent, engineered.
- Hybrid: $10,000–25,000 capital; $80–180/month. Grid reliability with solar backup; often the practical optimum.
Final Considerations
Utilities are the tiny house’s circulatory system: invisible when working, catastrophic when not. The right package depends on the site (grid distance, soil, rainfall, sun), the budget (capital vs monthly), and the philosophy (independence vs convenience). Audit first, size to the numbers, build in redundancy for the critical loads, and remember: at tiny house scale, every utility is cheaper, simpler, and more forgiving than its conventional counterpart. Small house, small systems, small problems.