In short: a whole-house (standby) generator is installed by a dealer and licensed trades in about a day of work, but the whole process usually takes several weeks: site visit, load calculation, permits, a pad, a gas line, a transfer switch, inspection and start-up. Generac puts a typical installed system at $8,000 to $16,000, generator included; installation labor alone runs about $1,500 to $5,000 on HomeAdvisor’s June 2026 data.
Outages are getting longer. U.S. electricity customers averaged 11 hours without power in 2024, nearly twice the yearly average of the decade before, mostly because of hurricanes Beryl, Helene and Milton (EIA, December 2025). Below: what installation costs, each step from sizing to start-up, placement and permits, how to choose a generator installer and the warning signs. At the end you can send us your project and we will reply ourselves.
Standby generator installation at a glance
- Who does the work: an authorized dealer for the brand, with a licensed electrician for the wiring and transfer switch and a licensed plumber or gas fitter for the gas line, depending on your state.
- Time on site: “usually takes hours,” says Generac; getting ready takes “multiple weeks” because of dealer availability, site preparation, the gas line and permits.
- Installed cost: $8,000 to $16,000 including the generator (Generac, 2026). HomeAdvisor’s 2026 data puts the installation part alone at about $1,500 to $5,000 in labor, plus materials.
- Permits: usually an electrical permit and a fuel (gas) permit, with an inspection before the system is put in service.
- No federal tax credit for fuel-burning generators in 2026. Check state and utility programs.
How much does standby generator installation cost?
A standby generator bill has two parts: the equipment (the generator and its transfer switch) and the installation (electrical work, the gas line or propane tank, the base, permits and start-up). The generator itself is often less than half the total. The figures below are dated vendor and maker estimates, not quotes. For running costs and a sample budget, see our full whole house generator cost guide.
Equipment versus installation
- Equipment: the generator, plus a transfer switch if it isn’t bundled. Generac’s own list prices (“MSRP starting at,” generac.com, October 3, 2026) are $3,649 for its 10 kW, $4,569 for 14 kW, $6,119 for 22 kW and $6,989 for 26 kW air-cooled units. Its 22 kW with a 200 A whole-house switch lists at $6,979, about $860 more than the generator alone (our math).
- Installation: labor, the transfer switch and wiring, any subpanel or panel upgrade, the gas line or propane tank, the base, permits, and start-up with activation. A gas meter that is too small is the gas utility’s call. Generac’s air-cooled units ship on a factory pre-mounted base pad, so a concrete slab isn’t always needed. HomeAdvisor’s ranges for each item are in the table below.
Typical installed cost by generator size
The last column is our estimate: the maker’s list price plus HomeAdvisor’s $1,500 to $5,000 labor, plus $1,200 to $4,400 for a transfer switch, a short gas line from an existing gas supply, two permits and a pad where one is needed. It leaves out propane tanks, panel upgrades, long gas runs and meter upgrades, which can add thousands.
| Size and type | Maker list price (Generac, Oct 2026) | HomeAdvisor unit range (June 2026) | Installed total (our estimate) |
|---|---|---|---|
| Air-cooled, 10 to 14 kW (essential circuits or a smaller home) | $3,649 (10 kW) to $4,569 (14 kW) | $2,000 to $3,500 (7.5 to 10 kW); $4,000 to $5,500 (14 to 18 kW) | about $6,300 to $14,000 |
| Air-cooled, 18 to 26 kW (most whole-house installs) | $6,119 (22 kW) to $6,989 (26 kW) | $5,000 to $6,500 (20 to 24 kW); $6,500 to $15,000 (26 to 32 kW) | about $8,800 to $16,400 |
| Liquid-cooled, 30 kW and up (large homes, big electric loads) | from $14,279 (Protector 30 kW) | $14,000 to $16,000 (36 to 38 kW); $16,200 to $21,000 (45 to 48 kW) | about $17,000 to $23,700 for 30 kW; more for bigger units |
Our middle row lands close to Generac’s $8,000 to $16,000. HomeAdvisor notes that models over 30 kW are liquid-cooled, which adds a few thousand dollars to the unit price, and bigger engines need more gas, which can mean larger piping.
Installation line items
| Line item | Range | Source |
|---|---|---|
| Whole system, generator included | $8,000 to $16,000 | Generac, 2026 |
| Installation labor | $1,500 to $5,000 | HomeAdvisor, updated June 2026 |
| Concrete pad | $50 to $75 per sq ft, or about $1,000 for 18 sq ft | HomeAdvisor, 2026 |
| Transfer switch, installed | $800 to $2,000 | HomeAdvisor natural gas generator page, June 2026 |
| New gas line | $300 to $1,000 if gas is already piped to the house; $2,000 or more from a nearby main | HomeAdvisor, June 2026 |
| Propane tank | $300 to $1,500 | HomeAdvisor, 2026 |
| Panel upgrade (100 A to 200 A), if needed | $750 to $2,000 | HomeAdvisor, June 2026 |
| Permits | about $50 to $200 each (some areas $400+) | HomeAdvisor, 2026 |
What pushes a quote up: a bigger generator, a long run from the gas meter or panel, a gas meter that has to be upgraded, an older panel, a propane tank you don’t have yet, rock or slope at the site, and local permit rules. What brings it down: a spot close to the meter and panel, an essential-circuits switch instead of whole-house, and booking outside storm season. Unit prices and a worked sample budget are in our whole house generator cost guide.
There is no federal tax credit for generators in 2026: the residential clean energy credit (25D) never covered fuel-burning generators and ended for all work after December 31, 2025. A few states and utilities have backup-power programs; see our incentives guide and your state page.
The installation process, step by step
Every dealer works a little differently, but the order of work is much the same. Here is what to expect, with a realistic sense of timing. The week numbers are our estimate, not a rule.
- Home visit and load calculation (week 1). The dealer looks at your electrical panel, your gas meter or propane plans and where the unit could sit. They list what you want to run: the whole house, or essentials such as the furnace, well pump, fridge and a few circuits. That decides the generator size and the transfer switch. Under the National Electrical Code (NFPA 70, Article 702), with an automatic switch the generator must carry everything it switches over, or use load management to shed big loads such as the air conditioner. You can rough out your own numbers first with our generator sizing calculator or our guide to what size generator you need.
- Written quote (week 1 to 2). A good quote separates the generator, transfer switch, pad, gas work, electrical work, permits and start-up. Get two or three and compare line by line.
- Permits and utility checks (weeks 2 to 4 or more). The installer pulls the permits. If you use natural gas, the gas utility may need to confirm your meter can supply the generator and your other gas appliances at the same time. Generac’s spec sheet says the fuel pipe must be sized for full load. With propane, Generac says the tank must be at least 250 gallons; a grill tank won’t work. Before any trench is dug for the gas line or wiring, someone should call 811 so buried utility lines are marked.
- Site preparation. Generac says dealers look for “a stable, well-drained area” with room for service, and usually set the unit on a concrete slab or pea gravel. The closer the spot is to the gas line and the electric meter, the less the installation costs.
- Install day. The unit is set, the gas line run and connected, and the transfer switch installed next to your main breaker panel. This usually fits in one long day. Generac’s guidelines say gas piping must follow NFPA 54 (natural gas) or NFPA 58 (propane) and be purged and leak-tested before the first start. Since its 2020 edition, the electrical code also calls for an emergency shutdown device outside the home (Section 445.18), where your state has adopted it.
- Inspection. The local building or electrical inspector checks the work, and in many places the gas piping gets its own inspection. Don’t let anyone put the system in service before the inspection your permit requires.
- Start-up and handover. The dealer registers the warranty, runs a simulated outage to show the switch-over, sets the weekly exercise time and explains maintenance. Ask for the paperwork and the permit sign-off.
What start-up should include. On Generac units, the generator must be activated online before it will start on its own in an outage, and Generac’s warranty runs from that activation. Generac’s start-up procedure also runs the unit at full rated load for 20 to 30 minutes while checking fuel pressure. Before the installer leaves, learn the controller’s AUTO and OFF buttons, when the weekly exercise runs and who to call. Keep the manual, permit sign-off and warranty record together.
After big storms, dealers book up for weeks. If you want a generator before hurricane or ice-storm season, start in the quiet months.
Where the generator can go: clearances and placement
Placement is about fire safety and exhaust. Generac’s installation guidance, based on the fire code for stationary engines (NFPA 37), calls for the unit to sit at least 5 feet from windows, doors and other openings, with clear space above and in front for service. Some tested units may sit as close as 18 inches from the wall. Your local code takes precedence, and the inspector has the final word.
The rule behind this is NFPA 37, Section 4.1.4: an engine installed outdoors must be at least 5 feet from openings in walls and from structures with combustible walls, unless the wall has a one-hour fire rating or the maker has shown that a fire inside its noncombustible enclosure won’t ignite anything outside. Generac had its air-cooled 10 to 24 kW units fire-tested by Southwest Research Institute, which is why its manual allows 18 inches from the back of the unit to a wall, while still asking for 3 feet at the front and ends, 5 feet open above, and no operable windows, doors or vents near the unit. Other makers publish their own clearances: check your manual and local code. Expect the installer to check:
- distance from windows, doors, vents and air intakes;
- clear space for service on the sides and front;
- a level, well-drained base that won’t flood, away from downspouts, sprinklers and sump pump discharge;
- property-line setbacks and homeowners’ association rules;
- the run length to the gas meter or propane tank and to the electrical panel.
Even a permanently installed generator burns fuel and makes carbon monoxide. Put battery or battery-backup CO alarms on every level of the home and outside sleeping areas, as the U.S. Consumer Product Safety Commission (CPSC) recommends.
Permits and inspection
Generac’s own support page says “all required permits must be secured before installation.” In most places that means an electrical permit (for the transfer switch and wiring) and a fuel permit (for the gas line or propane connection), sometimes a building or zoning review for the pad. HomeAdvisor’s 2026 data puts permits at about $50 to $200 each, though another HomeAdvisor page quotes $400 and up and notes that sources disagree. Your city or county building department sets the real fee.
Depending on where you live, also expect homeowners’ association approval, zoning setbacks from property lines and, in some towns, noise limits that matter mostly for the weekly exercise run. Get HOA approval in writing before work starts.
The transfer switch is what keeps generator power from flowing back onto the utility lines, which can injure line workers. That is why it’s installed by a licensed electrician and inspected. The electrical code requires transfer equipment that prevents the generator and the utility from ever being connected at the same time (Article 702). Our transfer switch guide explains automatic and manual switches and interlock kits.
How to choose a generator installer
Most standby generators are sold and installed through authorized dealers, not online. Generac says it has more than 6,000 independent dealers in North America, and Generac’s support page says only its authorized service dealers can do warranty work. A brand authorization is useful, but it is not a license. Check both. See our installers page for how SolutionEnergy works with installers, and each state guide links its licensing lookup.
- Licenses for both trades: Generac’s installation manual says wiring should be done only by “a trained and licensed electrician” and the fuel connection by “a qualified professional technician or contractor.” Look up the electrical contractor, and the plumber or gas fitter where your state licenses them, on your state’s site. Examples: Texas TDLR, Florida DBPR, the North Carolina Board of Examiners of Electrical Contractors, South Carolina LLR. In Illinois, electrical licensing is local, so check with your city or county. Each state page links its licensing board: Texas, Florida, North Carolina, South Carolina, Illinois.
- Brand status: confirm the dealer in the maker’s own dealer locator, not just on their truck: Generac dealer locator, Kohler (Rehlko) find a dealer and Briggs & Stratton dealers and installers. If you’re searching for a “Generac installer,” this is the place to start.
- Warranty registration: ask who registers the warranty and when. Generac’s 5-year limited warranty starts on “successful activation,” says the unit should be registered, and excludes damage caused by improper installation. Kohler’s runs from a start-up registered by a Kohler dealer or authorized service representative (otherwise from the purchase date). Get the confirmation in writing.
- Maintenance plan: Generac’s warranty says scheduled maintenance is required and should be done by an authorized dealer, with proof kept. HomeAdvisor puts professional service at about $80 to $300 a year (June 2026). Ask what a plan includes and costs. More in generator maintenance and repair.
- A written, itemized quote: generator model and kW on your fuel, transfer switch type and amps, load management, pad, gas or propane work, any panel or meter work, permits, start-up and activation, total price and payment schedule.
- Insurance: ask for a certificate of general liability insurance and, where your state requires it, workers’ compensation.
- Service after the sale: ask who answers when the generator won’t start during a storm, and how fast.
Questions to ask before you sign
- What size do you recommend, and can I see the load calculation?
- What does the generator make on natural gas versus propane? (Ratings on natural gas are lower: Generac’s 22 kW Guardian makes 19.5 kW on natural gas.)
- Whole-house or essential-circuits transfer switch, and does it include load management for the air conditioner?
- Does the quote include permits, the pad, the gas line, any gas meter upgrade and start-up?
- Who does the electrical and gas work, and what are their license numbers?
- What does the warranty cover, who registers it, and what maintenance keeps it valid?
- What is the payment schedule, and when is the final payment due (ideally after inspection)?
Red flags
- A price given over the phone without a site visit or load calculation.
- “We don’t need a permit” or “the inspection is optional.”
- No license number on the quote, or a license that doesn’t match the company name.
- A dealer you can’t find in the maker’s own dealer locator, or who can’t tell you who will do warranty work.
- A spot right under a window or next to a door “because it’s closer to the meter.”
- A large cash deposit, or pressure to sign today because “storm prices go up tomorrow.”
- A plan to connect the generator without a transfer switch or listed interlock.
- No mention of your right to cancel. Under the Federal Trade Commission’s Cooling-Off Rule, if you buy in your home (sales of $25 or more), the seller must tell you that you can cancel within three business days. Some states add their own rights. Read the cancellation section before you sign.
Can you install a standby generator yourself?
For most homeowners, no, and not because the bolts are hard. The job is gas piping, a transfer switch at your main panel, a load calculation and permits, and most areas require that work to be done or signed off by licensed trades. Generac says it is “strongly advisable to work with a certified professional,” and its installation manual warns that incorrect installation “may also result in the warranty being suspended or voided.” Generac’s warranty also excludes damage caused by improper installation and covers repairs only by its authorized dealers. Kohler’s warranty applies when the unit is found to be properly installed according to its manuals. Other makers set their own terms, so read the warranty before you buy. A mistake can backfeed the utility lines or leak gas.
Ways to save without doing it yourself: compare itemized quotes, pick a spot close to the meter and panel, and consider essential circuits instead of whole-house.
The lower-cost option: a portable generator and transfer switch
If a standby system is more than you need, a portable generator connected through a manual transfer switch or a listed panel interlock with an outdoor power inlet can run your essential circuits for much less. HomeAdvisor puts manual transfer switches at $500 to $2,000 (June 2026), and portable generators at $500 to $2,000. The trade-offs: you start, fuel and roll it out yourself, and it usually powers only a few circuits. A licensed electrician still installs the connection, usually with a permit; never plug a generator into a wall outlet. Our transfer switch guide compares switches, interlocks and inlets.
Portable generators are the bigger carbon monoxide risk. The CPSC says to run them outdoors only, at least 20 feet from the home, with the exhaust pointed away from windows, doors and vents, and never in a garage, even with the door open. Read how to run a generator safely and, to compare models, the best generators for a power outage.
What happens when you send us a request
You tell us about your home, your fuel and what you want to keep running. We read it and reply ourselves, usually with questions, a plain explanation of your options and what to ask installers. If you want, we can suggest an independent, licensed installer, and only then, and only the one you choose, sees your details. We never sell or negotiate installation contracts. Read more in how it works.
Get help with your project
Tell us about your project and we will connect you with a licensed, independent installer who serves your area. It is free, there is no obligation, and only the installer you choose gets your details. See how it works.
Standby generator installation questions
How long does it take to install a whole-house generator?
The work on site usually takes hours, about one long day. The full process takes several weeks: a home visit, the quote, permits, any gas meter work, the install, the inspection and start-up. Generac says timing depends on dealer availability, site preparation, gas line work and permits. After big storms, waits get longer, so plan ahead of your storm season.
How much does it cost to install a whole-house generator?
Generac puts a typical installed system at $8,000 to $16,000, generator included. By our estimate, an air-cooled 18 to 26 kW unit lands around $8,800 to $16,400 installed and a liquid-cooled 30 kW unit $17,000 or more. A propane tank, panel upgrade or long gas run adds to that.
Can I install a standby generator myself?
Generac says it is “strongly advisable to work with a certified professional,” and only its authorized dealers can do warranty work. The job includes gas piping, a transfer switch at your main panel and permits, which most areas require to be done or signed off by licensed trades. A mistake can backfeed the utility lines or leak gas. Leave it to licensed pros.
Do I need a Generac dealer to install a Generac generator?
Generac’s warranty says warranty repairs must be done by an authorized or certified Generac service dealer, and it excludes damage caused by improper installation. In practice most people buy and install through a dealer, who also activates the unit and registers the warranty. Find one in Generac’s dealer locator, then check their electrical and gas licenses with your state.
Do I need a permit for a home standby generator?
Almost always. Expect an electrical permit for the transfer switch and wiring and a fuel permit for the gas or propane connection, plus an inspection before the system goes into service. HomeAdvisor’s 2026 data puts permits at roughly $50 to $200 each, with some areas higher. Your installer should pull the permits; your city or county sets the fees.
How close to the house can a standby generator be?
Generac’s guidance, based on NFPA 37, is at least 5 feet from windows, doors and other openings, with space above and in front for service; some tested units may sit 18 inches from a wall. Local codes take precedence, and your inspector decides. Keep CO alarms with battery backup on every level of the home.
Does a standby generator need a concrete pad?
Not always. Generac’s air-cooled units come on a factory pre-mounted base pad and are usually set on a concrete slab or pea gravel in a stable, well-drained spot. Bigger units or local rules may call for concrete (about $1,000 for 18 square feet, HomeAdvisor).
Do I need a transfer switch for a whole-house generator?
Yes. The electrical code requires transfer equipment that keeps generator and utility power from ever meeting, so the generator can’t backfeed the power lines. Standby systems normally use an automatic transfer switch, sometimes sold with the generator. See our transfer switch guide.
What size standby generator do I need?
It depends on what runs at once, especially central air, electric heat, a well pump and an electric range. Ask for the installer’s load calculation, and try our generator sizing calculator or what size generator do I need.
Natural gas or propane for a standby generator?
If you have natural gas service, it is usually simpler: no refueling, as long as the gas keeps flowing. Without it, you need a propane tank of at least 250 gallons (Generac) and deliveries. Generators make a bit less power on natural gas than on propane, so size for the fuel you will use, and ask the utility whether your meter is big enough.
Keep exploring
Start at our generators hub, price your project with whole house generator cost, keep it running with generator maintenance and repair, and compare it with a battery in home battery vs generator or our backup power guide. For businesses, see commercial backup generators.
Sources
Generac: “Backup Generator Installation,” support pages, Guardian spec sheet, Installation Guidelines, 60 Hz Air-Cooled Generators 10 kW to 24 kW (Rev. A, October 2020), 5-year limited warranty for air-cooled standby generators, list prices and dealer count (2025 10-K). Kohler warranty policy TP-7219 (July 2022). HomeAdvisor whole-house generator, natural gas generator and electrical panel cost guides (June 2026). NFPA 37 Section 4.1.4 as quoted in Generac’s guidelines; NFPA 70 Articles 702 and 445 (2020 edition) via EC&M and UpCodes. U.S. EIA outage hours (December 2025). Dealer locators: Generac, Kohler (Rehlko), Briggs & Stratton. FTC Cooling-Off Rule (16 CFR 429). CPSC carbon monoxide guidance (2026). call811.com. State licensing boards. IRS on federal credits. Checked October 3, 2026. Any estimate on this page is ours and labelled.