Whole-House Generator Cost in 2026: Installed Price Breakdown

Most homes pay $8,000–$15,000 installed for a 14–26 kW standby generator. Here is every line item, what moves the price, and what a good quote should itemise.

A whole-house standby generator is not a $3,000 purchase. The unit is roughly half the bill; the other half is the electrical work, the fuel connection, the transfer switch and the permits that make it a legal, automatic system. Once you see the full list, the quotes you get will make sense — and you’ll spot the ones that leave things out.

The short answer

For a typical home — a 14 to 26 kW air-cooled unit on natural gas or propane — expect $8,000 to $15,000 fully installed in 2026. Three major cost surveys put the figures in the same neighbourhood: Angi reports an average around $5,200 with a range up to $13,500; HomeGuide and HomeAdvisor both show $8,000–$15,000 for a complete mid-size standby system, with larger liquid-cooled units reaching $20,000 or more.

The spread is wide because two variables dominate: generator size and how much electrical and gas work your house needs.

Cost by home size

If you don’t know which row you’re in, the sizing calculator will tell you in about a minute. Central air conditioning is usually what pushes a home from the middle row to the bottom one.

Line-by-line breakdown

The generator unit

Air-cooled units from the major brands run roughly $3,500 for a 10 kW to $8,000 for a 26 kW. Above about 22–26 kW, you move into liquid-cooled territory — quieter, longer-lived under sustained load, and considerably more expensive.

The transfer switch

This is the component people forget to budget for. An automatic transfer switch (ATS) senses the outage, starts the generator, and switches your house over — then switches back when the grid returns. Without it you have a portable generator with extra steps. Price depends on amperage (100 A vs 200 A) and whether it’s a whole-house switch or a load-management switch that sheds circuits to let a smaller generator cover more.

Electrical work

This is the most variable line. A house with a modern 200 A panel close to the generator location is the cheap end. An older panel that needs upgrading, a long conduit run, or a service disconnect that has to be relocated are what push this past $3,000. Standby systems are governed by NEC Article 702; your installer must meet it and the inspector will check.

Gas line

The generator wants to sit outside, on a level pad, at a code-required distance from windows and doors. The further that spot is from your gas meter or propane tank, the more pipe and the more labor. On natural gas, the utility may also need to upgrade your meter if the generator’s demand exceeds what it’s rated for — ask about this early, because it can add both cost and weeks of delay. Natural gas vs propane compared →

Permits

Nearly every jurisdiction requires an electrical permit and often a separate mechanical or gas permit. Your installer pulls them and passes the fee through. If a quote doesn’t mention permits, ask — an unpermitted install can void your homeowner’s insurance claim after a fire and will surface when you sell the house.

What moves the price

• A/C. The single largest factor in sizing. Dropping central A/C from the covered load can step you down one or two generator sizes.
• Distance. Generator-to-panel and generator-to-gas-meter distance drive the two most variable lines.
• Panel condition. An old or full panel means an upgrade before anything else.
• Fuel. Natural gas avoids a tank but may need a meter upgrade. Propane needs a tank (buried or above-ground) plus periodic refills.
• Local labor rates. Electrician wages vary by 40% or more between states. See cost by state.
• Timing. Demand spikes after major storms; lead times and prices go up with it. Shoulder seasons are cheaper and faster.

Running costs after installation

Budget for an annual service (oil, filter, spark plugs, load test) at roughly $200–$500, plus fuel during outages. A 20 kW unit on natural gas burns in the region of 200–300 cubic feet per hour at half load; on propane, about 2–3 gallons per hour. The unit also runs a short weekly self-test that uses a negligible amount of fuel.

What a good quote itemises

Ask every installer for a written quote that separates:

1. Generator make, model and kW rating
2. Transfer switch model and amperage
3. Electrical work, described
4. Gas or propane work, described, and whether a meter upgrade is included or excluded
5. Pad
6. Permits and inspection fees
7. Labor
8. Warranty terms and whether first-year maintenance is included

A single lump-sum number with no breakdown makes comparison impossible and usually hides something. Insist on a site visit before any firm price — an installer who quotes without seeing your panel and gas line is guessing.

Is it worth it?

That depends entirely on how often and how long your power goes out, and what an outage costs you: spoiled food, a flooded basement when the sump pump stops, a medical device, working from home. The state cost pages include your state’s average outage minutes per year from federal reliability data, which is the honest starting point for that math.