The standby machine is $3,000 to $6,000. Installed, the project runs $12,000 to $18,000. The real line items, plus the cheaper portable lane.
Budget
Quick answer: A whole-house standby generator is a $3,000 to $6,000 machine bolted into a $12,000 to $18,000 project. The install often costs as much as the generator once you add a concrete pad, gas line sizing, a possible meter upgrade, an automatic transfer switch, an electrician, a plumber, and permits. If your outages are a few short blackouts a year, a $700 to $2,500 portable plus a $400 to $850 interlock covers it for a fraction of that. Size the spend to your outage pattern, not the brochure.
Best for
Homeowners pricing a standby install before they take a dealer quote, so the final invoice holds no surprises.
Wrong fit
Buyers who already have the installed budget set and just want a brand shortlist.
Tradeoff
The standby machine is the cheap half. The pad, gas line, transfer switch, and two trades are where the real money and the change orders live.
A whole-house standby generator is a $3,000 to $6,000 machine bolted into a $12,000 to $18,000 project. The machine is the half of the bill the product page shows you. The other half is a concrete pad, gas line sizing, a possible gas meter upgrade, an automatic transfer switch, an electrician, a plumber, and permits, and nobody leads with that number.
That is the number you actually need before you take a dealer quote. We don't sell generators. We save you from buying the wrong one, and the fastest way to get burned is to price the machine and forget everything bolted to it. This guide prices the whole project, standby and portable.
If you already know you want standby and just need a shortlist, jump to the best home standby generators. If you are not sure standby is even the right lane, read standby vs portable first, because that one decision moves your budget more than the brand does.
Quick Answer: What a Whole-House Generator Actually Costs
Setup
Machine sticker
Install work
Real all-in
Whole-house standby (22kW-24kW)
$3,000-$6,000
$9,000-$12,000
$12,000-$18,000
Portable + interlock kit
$700-$2,500
$400-$850
$1,100-$3,350
Portable + manual transfer switch
$700-$2,500
up to $1,500
$1,200-$4,000
Home battery (short outages)
$10,000-$30,000 installed
included
$10,000-$30,000
Generac dominates the US home standby market, roughly 70 percent by most industry estimates, followed by Kohler, Briggs & Stratton, Cummins, and Champion. The machine sits at $3,000 to $6,000 for a common 22kW to 24kW unit, but the number on your final invoice is $12,000 to $18,000 once the install is done. That all-in figure is the one that matters.
The Machine Is Half the Project
Here is where the other half of the money goes, in the order these items usually land on the quote.
Concrete pad and site prep, about $1,000
A standby sits on a stable, level base, usually a poured concrete pad or a composite pad on gravel. Budget around $1,000. A flat yard near the meter and panel keeps this the cheap line. Sloped ground, poor drainage, or a long trench through roots and rock to a spot across the property is where it climbs.
Gas line sizing and a possible meter upgrade, $1,000 to $3,000+
This is the line that surprises people most. A 22kW to 24kW generator is a large gas appliance, and it has to get enough fuel without starving your furnace and water heater. Often the existing line is too small, so a plumber sizes and runs a new one, $1,000 to $3,000 or more depending on distance and pipe diameter. Sometimes the utility also has to upgrade your meter to deliver the volume, a separate cost on its own schedule. If you already have a large-diameter line and a high-capacity meter close by, you dodge most of this.
Automatic transfer switch and electrical, $2,000 to $5,000
The automatic transfer switch is what makes a standby a standby. It senses the outage, disconnects you from the grid, starts the generator, and switches the house over, with you touching nothing. The switch plus the electrician's labor runs $2,000 to $5,000, depending on whether you get a whole-house switch or a managed load center and how far the runs are.
Do not cut corners here, because the transfer switch is also the safety device that keeps your generator from backfeeding the grid and hurting a lineman. If you want the whole house covered automatically, this cost is the point of buying standby, and worth every dollar for that buyer. If you only need a few circuits kept alive, a portable with an interlock does the same job for far less, the interlock vs transfer switch question.
Permits, inspections, and sometimes a panel upgrade
Permits and inspections run a few hundred dollars and are not optional. A permitted install protects your insurance claim and your resale. Older homes sometimes also need a panel upgrade to handle the transfer switch and modern load, another $1,000 to $3,000. A recent panel with open capacity skips this cleanly. A 100-amp panel from the 1980s with no open slots does not, so plan for it now instead of finding it on a change order.
Brochure Number vs Real Number
What the product page shows
What the project actually costs
$3,000 to $6,000 machine
$12,000 to $18,000 installed
One clean "starting at" sticker
Pad, gas line, meter, transfer switch, permits, two trades
A number that does not move
A quote that moves with change orders
Here is a realistic worked example, built from the line items above. The numbers are illustrative, but the shape is exactly how these quotes drift.
Line item
First quote
Final invoice
Generator (22kW machine)
$4,900
$4,900
Concrete pad and site prep
$900
$1,100
Transfer switch + electrical
$2,600
$3,200
Gas line
$700
$2,900
Gas meter upgrade
not quoted
$1,800
Permits and inspections
$300
$500
Panel upgrade
not quoted
$1,600
Total
$9,400
~$16,000
The $9,400 quote was not dishonest. It assumed a short gas run, a big-enough meter, and a panel with room to spare. The site visit found a long run to an undersized line, a meter the utility had to upgrade, and a full panel. Three change orders later, the $9,400 job is a $16,000 job. This is why the only standby price worth trusting is the one after a real site survey, and why you get two or three quotes before you sign.
What Ownership Costs After the Install
The install is not the last check you write. A standby runs a weekly self-test that burns a little fuel and makes noise, usually a few minutes on a schedule you set. Service contracts run $200 to $400 a year, and you replace the starting battery every two to three years and change the oil on a schedule. None of it is dramatic, but it belongs in your budget from day one. The full breakdown is in generator maintenance cost.
The Portable Lane Is a Different Answer
Not every outage pattern needs $16,000 of standby. If you lose power twice a year for six hours, a portable does the job for a fraction of the price, and it is the smarter buy for that homeowner.
A quality portable runs $700 to $2,500. The part people skip is the legal, safe connection. An interlock kit runs $400 to $850 installed and powers your panel through a single inlet, or a manual transfer switch runs up to $1,500. Without one, you are running cords through a window or, far worse, backfeeding your panel, which can kill a lineman and start a fire. Budget the connection as part of the purchase.
A portable also carries a discipline the spec sheet never mentions: it runs outside, far from windows, doors, and vents, every time. Carbon monoxide from portable generators kills roughly 80 to 100 Americans a year (CPSC), and the deaths cluster in the days after a storm. That rule sells nothing and is not negotiable. Read never run a generator indoors before your first outage.
How to Budget by Your Outage Pattern
Lose power for days at a time? You are the standby buyer. Budget the full $12,000 to $18,000 installed, get two or three quotes after a site survey, and read what size generator do I need so you buy enough capacity without overpaying for a unit you never load.
Lose power for a few hours a few times a year? You are the portable buyer, all-in around $1,100 to $3,350 with an interlock. You trade automatic switchover and whole-house coverage for a machine that costs a tenth as much and still covers your real outage pattern. That is the smart buy, not a compromise.
Short outages with tight noise rules and no gas line? A home battery may beat both on silence, indoor safety, and zero fuel. It loses on multi-day outages, where a generator wins. We say that plainly on both sites. Weigh it in generator vs home battery and cross-check at homebattery.guide.
Whichever lane fits, price the whole project before you fall for a machine. Compare real installed numbers across the brand directory, and use the sizing tools to check capacity before a salesperson sizes it for you.
Frequently Asked Questions
Why does a whole-house generator cost so much more than the sticker price?
Because the machine is half the project. The $3,000 to $6,000 unit needs a concrete pad, a correctly sized gas line, often a meter upgrade, an automatic transfer switch, an electrician, a plumber, and permits. Add it up and the finished project is $12,000 to $18,000 installed. The product page only shows you the machine.
What is the real installed cost of a 22kW Generac?
Plan for $12,000 to $18,000 installed for a typical 22kW to 24kW unit, even though the machine itself is around $4,000 to $6,000. The final number depends on your gas line, a possible meter upgrade, the electrical runs, and whether your panel needs work. Get two or three quotes after a site survey, not before.
Can I install a standby generator myself to save money?
Almost never worth it, and often not legal. A standby ties into your gas supply and main panel, needs permits and inspections, and requires a transfer switch wired so it cannot backfeed the grid. Most jurisdictions require a licensed electrician and plumber, and a DIY install can void both the warranty and your insurance. This is the one lane where the trades earn their fee.
Is a portable with an interlock really enough for a whole house?
For short, occasional outages, often yes, at a tenth of the cost. A $700 to $2,500 portable plus a $400 to $850 interlock powers your key circuits: fridge, furnace blower, well pump, a few lights and outlets. What you give up is automatic switchover and running everything at once. If your outages are a few hours a few times a year, that is a smart trade.
What surprise costs turn a generator quote into a bigger bill?
Three usual suspects: an undersized gas line, a gas meter the utility has to upgrade, and a panel with no room for the transfer switch. Any one can add $1,500 to $3,000. That is how a $9,400 quote becomes a $16,000 invoice. A proper site survey catches them before you sign, so the first quote should always follow a site visit.
How much does it cost to run and maintain a standby generator each year?
Budget $200 to $400 a year for a service contract, plus a starting battery every two to three years and periodic oil changes. The weekly self-test burns a little fuel and makes some noise. Not a large number, but a recurring one, so include it from day one. Full detail is in generator maintenance cost.
Is a home battery cheaper than a whole-house generator?
Not usually cheaper, but sometimes the better fit. A home battery runs $10,000 to $30,000 installed, similar to a standby project, and wins on silence, indoor safety, and zero fuel for short outages. It loses on multi-day outages, where a generator keeps going and a battery runs down. If your outages are short and noise rules strict, weigh it at homebattery.guide.
Methodology
These guides are built from manufacturer documentation, public specifications, primary research where health claims matter, and repeated buyer questions that show up in real ownership and installation decisions.
Manufacturer responses can clarify pricing bands, warranty terms, support footprint, or common mistakes. They do not move a page up the shortlist on their own.
