A whole house standby generator typically runs $7,000 to $25,000 or more installed, with the generator itself often the smaller part of the bill.
For the full breakdown, see our best Whole-House Backup Generator guide.
The number that surprises people isn’t the sticker price on the generator — it’s everything bolted around it. The unit is usually the cheapest line on the invoice.
That gap between the box price and the finished price is where most budgets blow up, so here’s what each piece actually runs and which choices swing the total the hardest.
What Drives The Installed Price Up Or Down
The size of the generator and how much of your house it has to carry decide most of the price. A unit sized for a few essential circuits costs far less to install than one backing up central air, electric appliances, and a well pump.
Higher-output units cost more, but they also drive bigger transfer switches and heavier wiring.
The real swing factors:
- Unit output — a 10kW essentials unit versus a 26kW whole-home machine.
- Transfer switch — whole-house switches cost more than a handful of essential-circuit switches.
- Gas line work — a long run from the meter, or a propane tank install, adds hundreds to thousands.
- Electrical panel and code work — older panels often need upgrades to pass inspection.
- Site access — trenching, pad pouring, and tight side yards all add labor.
- Permits and inspection — required almost everywhere, and priced locally.
Unit Price Versus Installed Price
The most common mistake is reading the generator’s price tag and budgeting for that alone.
Professional electrical work and code compliance are mandatory, which is why the installed total for a full-home unit commonly lands between $8,000 and $23,000 and can exceed $25,000 in high-cost markets or complicated installs.
If you’re comparing models before you commit, it helps to see how the popular whole house backup generator options stack up on output and price side by side.
| Cost Line | Typical Range | Notes |
|---|---|---|
| Generator unit | $3,769–$7,899 | Depends on output; 26kW models sit near the top. |
| Automatic transfer switch | $500–$2,000+ | Whole-house switches cost more than essential-circuit versions. |
| Electrical panel work | $1,000–$4,000+ | Older panels often need upgrades to meet code. |
| Gas line or propane hookup | $500–$3,000+ | Long runs and new tank installs push this higher. |
| Concrete pad and mounting | $300–$1,000 | Access and site prep affect labor time. |
| Permits and inspection | $200–$1,500 | Varies widely by city and county. |
| Full installed total | $7,000–$25,000+ | Site-dependent; larger full-home systems trend high. |
Installation Steps And What To Expect
A standby install runs in a fixed order: size the generator for your home’s loads, choose the unit and automatic transfer switch, complete the electrical and gas work, then permit and inspect. Each step is where cost gets added or trimmed.
Generac exposes a Spec Sheet for its 26kW models, so you can match running and starting wattage against your actual appliances before buying.
The installation itself is professional-only work. A licensed electrician wires the transfer switch into your panel so the house flips to standby power automatically, and a gas fitter ties the unit to your natural gas line or propane supply. If either trade requires a permit in your area, that paperwork is part of the bill.
One compatibility gate to check early: your utility service and gas meter capacity. A 26kW unit needs adequate gas volume, and a weak supply means either a smaller generator or a propane tank. Confirm that before pricing anything.
Get at least two local quotes.
References & Sources
- Generac. “Home Standby Generators” Lists U.S. residential standby pricing from $3,769.00 upward.
- Generac. “26kW Home Standby Generator, Model 7327” MSRP starting at $7,159.00; spec sheet available.
- Generac. “26kW Guardian Series with Whole-House Switch, Model 7291” MSRP starting at $7,899.00.
