Quick answer: buying a home standby generator is a five-step decision, in this order: confirm your outage pattern justifies one, size the unit to your actual circuits, pick a fuel source, budget the full installed price, then choose the installer with more care than the brand. Most buyers do these in reverse, overspend on the box, and underthink the installation. Work through the steps below and you will spend less and get better results. If you only remember one thing: the installer matters as much as the generator.
Step 1: Confirm a standby is the right type at all
A home standby generator is a permanently installed unit that sits outside your house, connects to your gas line, and starts itself within seconds of a power cut. That automation is the entire product. A portable generator with a transfer switch costs around a quarter as much and covers most of the same loads, but you roll it out and start it yourself. Our standby vs portable comparison walks that tradeoff in detail.
The honest test is your outage history. If your area loses power a few times a year for under a day, a portable plus a transfer switch is usually enough money spent. If outages are frequent, long, or you have loads that cannot tolerate an interruption, a sump pump, medical equipment, a home office you work from, the automatic switchover earns its price. Check your state's outage record in our power outages by state reference before assuming you need the bigger spend.
Step 2: Size the generator to your circuits, not your ambition
Standby units are sold by kilowatts, and the common mistake is buying capacity you will never use. The right size is set by two numbers: the starting wattage of your air conditioner and the sum of the circuits you actually want live. A 2,500 to 3,500 sq ft home with central AC typically lands in the 20 to 22 kW class. Smaller gas-heated homes that only need essentials, fridge, furnace, lights, sump, internet, can get by in the 7 to 14 kW range at a much lower installed cost.
Do not guess this. Run your appliance list through our generator size calculator, which converts a wattage inventory into a capacity class in a few minutes. Undersizing trips breakers on motor start-up; oversizing means you paid for kilowatts that sit idle. The generator comparison tool then shows how a specific standby model stacks up against gas portables for your exact list.
Step 3: Choose your fuel before your brand
Almost every home standby generator runs on either natural gas or propane, and many switch between both. Natural gas means no refueling ever, but it assumes your street supply stays up during the outage, which is usually, not always, true. Propane stored in an on-site tank keeps you independent of the utility, at the cost of tank sizing and refills. Our natural gas whole house generator guide covers the fuel decision in depth, and the propane tank sizing guide helps if you go the tank route.
One fuel note that surprises people: the same unit produces slightly less power on propane than on natural gas. Check the spec sheet for both ratings before you commit.
Step 4: Budget the installed price, not the sticker
The box is roughly half the cost. Installation adds a transfer switch, a concrete pad or gravel bed, gas line work, and electrical labor, and installed totals for a whole-house class unit commonly start around $6,000 and climb with size and site difficulty. Permit fees and any needed gas meter upgrades sit on top. Our whole house generator cost breakdown itemizes where the money goes.
Two ways to keep the number sane. First, get three installer quotes for the same unit; pricing varies wildly because installation labor is local and unstandardized. Second, revisit step 2: dropping from whole-house coverage to an essentials-circuit setup often cuts the installed price nearly in half. Searching current home standby generator pricing before the quotes arrive gives you a floor for negotiation.
Step 5: Pick the installer with more care than the brand
At the 20 kW class, Generac, Kohler, and Champion all build competent units, and our best whole house generators by home size ranks the current field. The bigger reliability variable is who installs and services it. A standby generator is an appliance with an engine, and it needs an annual exercise cycle and occasional service for the decade-plus you will own it.
Ask any installer three questions before signing: who services it locally after the warranty, what the response time is on a no-start call in January, and whether they handle the permit themselves. Good answers to those matter more than a badge on the enclosure. Our whole house generator installation guide covers what a competent install should include.
What a home standby generator does not do
It will not run forever without attention, and it will not power a house that lost gas supply along with the grid. It also does not improve daily life in any way you will notice until the night it matters, which is exactly why sizing and installation discipline matter more than brand loyalty. Treat the purchase as a decade-long relationship with a local service shop, and the specific badge on the unit becomes a secondary decision.
FAQ
How much does a home standby generator cost installed?
Installed totals commonly start around $6,000 for an essentials-circuit setup and rise with capacity and site work. The equipment is roughly half the bill; transfer switch, pad, gas, and electrical labor make up the rest. See our full cost breakdown.
What size home standby generator do I need?
Most homes with central AC land in the 20 to 22 kW class; gas-heated homes covering only essentials can use 7 to 14 kW. Size from your appliance starting wattage, not floor area alone. The generator size calculator does this from a wattage list.
Do I need a permit for a standby generator?
In most US jurisdictions, yes: the install involves gas and electrical work and typically needs a permit and inspection. Reputable installers handle this as part of the job, which is one reason to ask about it before signing, as in step 5 above.
How long does a home standby generator last?
With annual maintenance, standby units are commonly quoted a service life measured in decades, with engine rebuilds possible at the far end. The maintenance schedule in the owner's manual, not the brand, is the main driver of how long yours actually runs.
