How Much Does a Whole-House Generator Cost?

A whole-house standby generator typically costs about $8,600 to $13,700 installed on natural gas, depending on size, and more if you need a new propane tank. A 22 kW unit, the most common size for a typical home with central air, runs about $10,200 to $12,800. Unusually for a home improvement, a backup generator also recovers most of its cost at resale.

Installed cost by size

Equipment prices are Generac's list prices for its Guardian air-cooled models with a whole-house automatic transfer switch, which switches your home over to generator power when the grid goes down. Installed totals add $3,000–$5,000 for installation labor, $150–$400 for a concrete pad, and $80–$450 for permits.

Natural gas vs. propane

If your home already has natural gas service, the generator connects to it and never needs refueling. Without natural gas, the generator runs on propane from a tank; if you don't already have one, a tank adds about $400 to $1,800. Long gas line runs from the meter to the generator also add cost, so the closer the generator can sit to both the gas meter and the electrical panel, the cheaper the installation.

What size do you need?

A 14 kW generator covers essential circuits — refrigerator, furnace fan, well pump, lights, and outlets — in a smaller home. A 22 kW unit can run most homes entirely, including central air conditioning. Larger homes, or homes with several big electric loads like electric heat or an EV charger, may need 26 kW or a liquid-cooled unit. An installer will size yours from a load calculation.

Does a generator add resale value?

In Zonda's 2025 Cost vs. Value Report, a defined backup generator project — a propane standby system with an automatic transfer switch, averaging $13,534 — recovered about 95% of its cost at resale, one of the highest returns in the report. It was the first year a backup generator made the report's top 10, and returns topped 100% in hurricane- and storm-prone regions.

Sources

• Generac — 22kW Guardian standby generator with transfer switch
• HomeGuide — Whole house generator cost (2026)
• Cost vs. Value 2025 — Backup Power Generator (project scope)