How Much Does Generator Installation Cost?
By the HomeLintel Editorial Team · Reviewed 2026-08-24
A whole-house standby generator typically costs $5,500–$16,000 installed — around $9,500 for most homes — covering the unit, concrete pad, automatic transfer switch, fuel connection, and electrical work. It starts itself within seconds of an outage and runs on natural gas or propane.
The honest budget alternative deserves equal billing: a quality portable generator plus a professionally installed interlock kit and inlet ($500–$1,200 of electrical work on top of a $600–$1,500 generator) backs up a home's essentials for a fifth of standby cost — you just have to wheel it out and start it.
Cost breakdown: standby installation
| Item | Typical range | Notes |
|---|---|---|
| Standby unit 10–14 kW (essentials+) | $3,000 – $5,000 | Runs most of a home outside big AC loads. |
| Standby unit 18–26 kW (whole house) | $4,500 – $7,500 | Everything including central air. |
| Automatic transfer switch | $500 – $1,500 | The brains; sized to service amperage. |
| Electrical + gas installation labor | $2,000 – $5,000 | Pad, conduit, gas line sizing/run, commissioning. |
| Gas meter/regulator upgrade | $0 – $1,200 | Big generators need more gas flow than many meters supply. |
| Permit + inspections | $200 – $800 | Electrical and gas/mechanical; placement rules apply. |
| Portable + interlock alternative | $1,100 – $2,700 total | Generator, inlet box, interlock, install. |
Sizing: back up needs, not the spec sheet
The dealer default is 'whole house' (18–26 kW). The money-saving question is what you actually need through an outage: refrigeration, some lights and outlets, furnace blower or a modest mini split, internet, and the sump pump — that's a 10–14 kW load in most homes, thousands cheaper installed and cheaper on fuel. Central AC is the load that forces big generators; decide whether outage-week AC is worth $3,000–$5,000 before defaulting to it. A load-management module can also let a smaller unit juggle large loads.
Fuel: natural gas, propane, or gasoline
Natural gas standby is the convenience king — runs indefinitely, no refueling — with the caveat that extreme events occasionally interrupt gas service too. Propane stores on-site (500-gallon tank ≈ 4–7 days continuous) and suits rural homes. Gasoline portables demand stored fuel that ages, and refueling runs during the exact emergency everyone else is having. This is why the natural-gas standby dominates suburbs and the propane standby dominates the countryside.
The safety line that isn't optional
Never backfeed a house through a dryer outlet: it energizes utility lines, and linemen die from exactly this. The interlock or transfer switch isn't bureaucracy — it's the mechanism that makes backup power safe, and it's required by code everywhere. Equally non-negotiable: portables run outdoors only, 20+ feet from openings — CO from generators kills dozens of Americans every outage season. Standby units handle placement clearances through the permit process.
Frequently asked questions
How much does a whole-house generator cost installed?
Typically $9,500 for a mid-size (14–18 kW) natural-gas standby with automatic transfer switch; $5,500–$16,000 covers the realistic range from essentials-sized to large homes with meter upgrades.
Is a whole-house generator worth it?
Where outages are frequent or long (hurricane country, ice-storm belts, wildfire-shutoff zones), and for homes with medical equipment, sump-dependent basements, or work-from-home stakes — commonly yes, and it modestly helps resale there. For rare-outage areas, the portable-plus-interlock setup delivers most of the resilience at a fraction of the cost.
How long do standby generators last?
20–30 years or roughly 2,000–3,000 running hours with annual service. They self-exercise weekly; oil and filter service ($150–$300/year professionally) is the upkeep.
Can a generator run an air conditioner?
Central AC needs a large generator (18 kW+ for typical 3-ton systems) or a soft-start kit that tames compressor inrush on mid-size units. Window units and mini splits run happily on much smaller generators — an outage-cooling strategy worth considering.
Related resources
Sources & methodology
- US CPSC — Portable Generator Safety — CO safety requirements
- FEMA — Power Outage Preparedness — outage planning context
Cost ranges are HomeLintel editorial estimates built from the listed sources and our published assumptions — they are not quotes. Last reviewed 2026-08-24. See how we estimate costs.