Generator Installation Cost (2026): $14,897 to $22,919
What a contractor's cost is in 2026 to install a home standby generator or connect a portable one: price by size, what the site adds, clearances, fuel demand, the electrical rules, and labor hours.
The assumptions
This model assumes
- Natural gas, 200 amp service, pad, 25 ft feeder and 20 ft gas line unless stated
- Job cost before markup: labor, equipment and materials, no tax
- National prices with no regional adjustment
- A $225 permit allowance on each generator job, not in the job cost shown
- Prices from Clamp's catalog on November 11, 2026
The model, step by step
Priced through Clamp's catalog on November 11, 2026 for a natural gas standby generator with an automatic transfer switch, a poured pad, 25 ft of feeder and 20 ft of gas line. Every price in this guide is job cost before markup: what the labor, equipment and materials cost you. These are national prices with no regional adjustment. Each job also carries a $225 permit allowance, except the generator-ready prep (none) and the propane tank job ($475).
Standby, whole house
Drawn for this guide in the style of Quick Clamp's sketch pad: the parts of a whole-house standby job. The pad has no generator tool, so this is an illustration with typed labels. Demo data.
| Size | Job cost | Hours |
|---|---|---|
| 14 kWAir-cooled | $10,015 | 38 |
| 18 kWAir-cooled | $11,459 | 38 |
| 22 kWAir-cooled | $11,459 | 38 |
| 26 kWAir-cooled | $12,641 | 38 |
| 28 kWAir-cooled | $13,232 | 38 |
| 30 kWLiquid-cooled | $19,259 | 38 |
| 38 kWLiquid-cooled | $23,419 | 38 |
| 48 kWLiquid-cooled | $24,459 | 38 |
The size of the unit moves the price less than the site does. Where the generator sits relative to the electric meter, the panel and the gas meter decides the feeder, the gas run and the trench.
| Job | Job cost | Hours |
|---|---|---|
| 22 kW, as abovePad, 25 ft feeder, 20 ft gas | $11,459 | 38 |
| No pad, no gas runBeside the meters | $10,753 | 34 |
| Gas meter upgradeUtility swaps the meter | $12,959 | 38 |
| Set 60 ft away75 ft feeder, 60 ft trench | $13,356 | 50 |
| 14 kW, critical loadsSubpanel, circuits moved | $11,190 | 46 |
| Propane, new tank500 gallon tank set | $15,460 | 40 |
The choices
Gas meterThe utility's meter and regulator swap adds $1,500 in Clamp. Utilities set their own charge, and some take weeks.
DistanceA unit 60 ft out, with the feeder and gas trenched, is $13,356 and 50 hours.
Critical loadsA 14 kW unit with a critical loads panel is $11,190: the smaller unit saves $1,444 and moving the circuits adds $1,175, so it lands only $269 under the 22 kW whole-house job.
PropaneWith a new 500 gallon tank set, $15,460. Clamp carries a second permit allowance of $250 for the tank; whether one is required depends on the state and the tank size. Clamp's tank price runs above the installed prices we found.
Liquid-cooledAir-cooled home units top out at about 26 to 28 kW, depending on the maker. Larger units are liquid-cooled. A 30 kW job is $19,259.
The fire code's general rule is 5 ft from openings and from walls that can burn. Makers fire-test their units to sit closer to a wall, and that reduced clearance belongs to the model that was tested.
Where it can sit
Drawn for this guide in the style of Quick Clamp's sketch pad: Generac's clearances for its 10 to 28 kW units, from its January 2026 manual. Read the manual for the unit you are setting. Demo data.
Before you pour the pad
Wall18 in behind the unit in that manual. The reduction is for the wall, not for openings.
Service space3 ft at the front and at both ends, and 5 ft clear above.
OpeningsDoors, windows and air intakes follow the adopted code. Local rules on intakes, lot lines and noise can ask for more.
Carbon monoxideExhaust can reach an opening that meets the clearance. Check where it will go.
Size the gas pipe and check the meter for the generator at full load, on top of everything else in the house. These are Generac's current air-cooled units.
| Size | Gas/hr | LP/hr |
|---|---|---|
| 14 kW14 kW on natural gas | 243 cu ft | 2.92 gal |
| 18 kW17 kW on natural gas | 235 cu ft | 2.87 gal |
| 22 kW21 kW on natural gas | 311 cu ft | 3.71 gal |
| 26 kW24 kW on natural gas | 316 cu ft | 3.95 gal |
Reading the table
The meterA 22 kW unit can ask for 311 cu ft an hour by itself. Add the furnace, water heater and range, and ask the utility whether the meter passes it.
Rated on propaneThe size on the box is the propane rating. On natural gas the 22 kW makes 21 kW.
Propane tanksTank sizes are water capacity. Under the 2017 propane code a 125 to 500 gallon tank sits 10 ft from the building, and its relief valve and fill connection 10 ft from the generator.
A power inlet on the outside wall, a cable to the panel, and an interlock that keeps the main and the generator breaker from being on together: $778 at 30 amps and $847 at 50, about 4 hours.
Portable hookup
Drawn for this guide in the style of Quick Clamp's sketch pad: a portable generator's connection to the house. The pad has no inlet tool, so this is an illustration with typed labels. Demo data.
| Job | Job cost | Hours |
|---|---|---|
| 30 amp inlet, interlock25 ft of cable | $778 | 4 |
| 50 amp inlet, interlock25 ft of cable | $847 | 4 |
| 50 amp, 60 ft runLonger cable | $1,018 | 4 |
| Generator-ready prepConduit and spaces only | $893 | 5 |
Doing it right
The interlockUse the kit made for that panel, with its breaker and breaker retainer. Write the panel model and kit number on the estimate.
No backfeed cordsA cord with a plug on both ends is never acceptable. The safety commission warned against them again in March 2026.
The neutralA portable with its neutral bonded to the frame can trip its own GFCI on a house connection. Use transfer equipment that switches the neutral, or have the maker's authorized dealer convert the generator to a floating neutral.
SizeA 30 amp inlet is 7,200 W at 240 V and a 50 amp inlet is 12,000 W. The generator's running watts are the real limit.
Where it runsAt least 20 ft from the house, exhaust pointed away. An estimated 93 people died in 2022 from carbon monoxide where a generator was the only product involved.
Checked on November 11, 2026. The electrical code is adopted state by state, and sometimes city by city, so the edition in force depends on where the job is.
What applies
Transfer equipmentEvery standby system needs transfer equipment that keeps the generator and the utility apart.
SizingWith automatic transfer, the generator carries the whole load it picks up, or the load a load-management system allows.
The 200 amp switchA 200 amp transfer switch matches a 200 amp service. A 22 kW generator makes about 92 amps.
Code editionThe 2026 edition is already in force in some states, including Massachusetts and Texas. Most others are on 2023 or 2020, a few are older, and some leave it to the city or county. Ask the inspector.
PermitsExpect an electrical permit and often a gas or plumbing permit; some places add zoning review.
Tax creditA home standby generator gets no federal residential clean energy credit, and that credit ended for spending after December 31, 2025.
Clamp carries 38 person-hours on the standard job: 28 to set, wire and start the generator, 6 for the transfer switch, and about 4 for the gas line and the pad.
Against what installers publish
Site timeOne dealer describes one to two days on site for a standard install, without stating the crew.
What that meansTwo people for two days is 32 person-hours. Two for one day is 16. Clamp's 38 sits above that range.
StartupGenerac's manual calls for 20 to 30 minutes at full rated load, a fuel pressure check and a simulated outage. That time is inside the generator line.
Before the crew arrivesThe permit, the utility and the gas meter set the calendar. Weeks, not days.
A house with a 200 amp service and natural gas loses power a few times a year. Option A connects the owner's portable generator through a 50 amp inlet and an interlock: $847. Option B installs a 14 kW standby unit on a critical loads panel: $11,190 and 46 hours. Option C installs a 22 kW unit on the whole house with a gas meter upgrade: $12,959 and 38 hours.
| Line | Job cost | Hours |
|---|---|---|
| 22 kW unit and switch1 ea | $6,500 | |
| Set and wire the generator1 ea | $3,200 | 28.0 |
| Gas meter upgrade1 ea | $1,500 | |
| Install the transfer switch1 ea | $850 | 6.0 |
| Gas line, labor20 lf | $380 | 3.6 |
| Gas line, pipe20 lf | $170 | |
| Feeder cable28.75 lf | $122 | |
| Pad, concrete16 sf | $84 | |
| Conduit25 lf | $81 | |
| Pad, labor16 sf | $72 | 0.8 |
The job
Every line priced
The job in Clamp, and the estimate it prices: $12,959 at job cost, by trade. Recreations of the Clamp app with demo data.
What it means
Every generator job, line by line
Clamp reads the size, the fuel, the transfer arrangement, the runs, the trench and the meter upgrade from the words, and prices the unit, the switch, the pad, the gas line and the permit, with labor hours on each line.
The generator is a known price. The site is the estimate.
Questions
How much does it cost to install a whole house generator?
In Clamp's catalog a 22 kW natural gas standby generator with a 200 amp automatic transfer switch, a pad, 25 ft of feeder and 20 ft of gas line is $11,459 in job cost before markup, plus a $225 permit. The ballpark price range is $14,897 to $22,919. Generac advertises $8,000 to $16,000 installed.
How much does a generator interlock kit cost to install?
An interlock, a power inlet and 25 ft of cable is $778 at 30 amps and $847 at 50 amps in job cost before markup in Clamp's catalog, about 4 hours. The ballpark price range at 50 amps is $1,101 to $1,694.
How long does it take to install a standby generator?
One dealer describes one to two days on site. Clamp carries 38 person-hours for a standard air-cooled install. The permit, the utility and any gas meter upgrade take weeks before that.
How close to the house can a standby generator be?
It depends on the model. Generac's current manual for its 10 to 28 kW units allows 18 in behind the unit, with 3 ft at the front and both ends and 5 ft above. Doors, windows and air intakes follow the adopted code, which generally means 5 ft.
Is there a tax credit for a home generator in 2026?
No residential clean energy credit applies to a home standby generator, and the IRS says that credit ended for expenditures made after December 31, 2025.
Sources & provenance
- Clamp's catalog, priced by script Clamp (research)
- Articles 702, 705, 706 and 710: optional standby systems North Carolina Office of State Fire Marshal (official source)
- Panelboard application guide UL Solutions (official source)
- CPSC warns consumers to stop using male-to-male extension cords US Consumer Product Safety Commission (official source)
- CPSC warns of generator, carbon monoxide and fire hazards ahead of hurricane season US Consumer Product Safety Commission (official source)
- Non-fire carbon monoxide deaths associated with the use of consumer products: 2022 annual estimates US Consumer Product Safety Commission (official source)
- Why does the generator GFCI breaker trip on some generators when used with a transfer switch? Generac (research)
- Air-cooled home standby generators 10 to 28 kW installation manual (A0004332575, Rev. D) Generac (research)
- 10 to 18 kW air-cooled standby generator specification sheet (A0005151081, Rev. C) Generac (research)
- 22 to 28 kW air-cooled standby generator specification sheet (A0005151077, Rev. B) Generac (research)
- Placing LP-gas containers fact sheet National Fire Protection Association (official source)
- Massachusetts Electrical Code Commonwealth of Massachusetts (official source)
- Commission adopts rules: electricians Texas Department of Licensing and Regulation (official source)
- FAQs for modification of sections 25C, 25D, 25E, 30C, 30D, 45L, 45W and 179D under Public Law 119-21 IRS (official source)
- Generac 7325 home standby generator, product page Ace Hardware (research)
- Backup generator installation Generac (research)
- Whole house generator cost Wolf River Electric (research)