Whole house generator cost

A whole-house standby generator costs $7,000 to $20,000 installed, with most 22 kW installations landing between $10,000 and $14,000. Labor alone is $3,000 to $5,000 of that.

It is one of the larger discretionary purchases a homeowner makes, and the honest question is not what it costs but how many hours a year your power is actually out. In much of the country the answer makes a portable generator the better buy.

Cost by size

Broken down on a typical 22 kW install:

• The generator: $4,500 to $8,000
• Automatic transfer switch: $500 to $2,000
• Concrete or composite pad: $200 to $800
• Gas line, sized and run: $500 to $2,500
• Electrical connection and permit: $800 to $2,000
• Labor: $3,000 to $5,000

Standby against portable

A portable generator is $500 to $2,000 for the unit. With a manual transfer switch or an interlock kit at $500 to $1,500 installed, it can safely power selected circuits. You have to go outside, start it, and refuel it every eight to twelve hours. It cannot start itself when you are away.

A standby generator is permanently installed, runs on natural gas or propane, starts itself within seconds of an outage, and needs no attention. It also exercises itself weekly, which the neighbors will notice.

The arithmetic is a straightforward comparison of inconvenience against roughly $10,000. If your power fails twice a year for four hours, a portable is plainly enough. If you are on a well, so an outage means no water, or you have medical equipment, a home business, or a freezer full of food, or your outages last days after storms, standby earns its price.

Fuel matters more than people expect

Natural gas is the easy case, if you have a supply. Unlimited runtime, nothing to store. The catch is capacity: a 22 kW generator needs a lot of gas, and the existing meter and line often cannot deliver it alongside the furnace and water heater. Upsizing the service is a utility job and can add $500 to $3,000 and several weeks.

Propane works anywhere. A 22 kW unit under load uses roughly 3 to 3.5 gallons an hour, so a 500 gallon tank gives about six days of continuous running. Tank rental or purchase is $500 to $3,000.

Diesel is mostly commercial and needs fuel that degrades in storage.

Ask the installer to confirm gas capacity before you buy the generator. Discovering the meter is too small after the unit is on the pad is a common and expensive sequence.

What the quote should include

• A load calculation showing what the generator will actually carry
• The transfer switch type: whole-house, or a subpanel of selected circuits
• Gas line sizing and who confirms capacity with the utility
• The pad, and whether it meets local flood elevation requirements
• Permits, both electrical and gas or mechanical
• Setback distance from windows, doors and the property line, which is code-driven and sometimes the reason a unit will not fit where you want it
• Commissioning and the first service
• The warranty, and whether it requires annual servicing by an authorized dealer

That last item is worth reading. Many warranties are conditional on documented annual maintenance, which costs $200 to $500 a year.

Selected circuits cost much less

You do not have to power the whole house. A managed transfer switch feeding a subpanel of chosen circuits, the furnace, fridge, well pump, a few lights, the router, is a far smaller generator and a far smaller bill: $6,000 to $9,000 installed rather than $12,000.

Load management modules that shed the air conditioner when the electric range comes on let a smaller generator behave like a larger one. Ask about them before sizing up.

Frequently asked questions

How long do they last?

Fifteen to twenty-five years, or roughly 2,000 to 3,000 running hours, which most houses never approach. The battery needs replacing every three to four years and is the most common reason a standby generator fails to start.

How loud is it?

Sixty to seventy decibels at 20 feet under load, comparable to an air conditioner. The weekly self-test runs five to twenty minutes and can be scheduled for a civilized hour.

Does it need maintenance?

Yes. Oil and filter annually or every 100 to 200 hours, spark plugs and air filter periodically, and the battery every few years. Budget $200 to $500 a year, and check whether the warranty requires it.

Will it lower my insurance?

Some insurers give a small discount, typically 5% or less on the relevant portion of the premium. It is worth asking, and it is not a reason to buy one.

Does it add value at resale?

Modestly, and much more in areas with a reputation for outages. In a region where storms routinely take power out for days, it is a genuine selling point. Elsewhere buyers largely ignore it.