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Cost guide

Whole-House Generator Installation Cost

Installing a permanently mounted standby generator with an automatic transfer switch for whole-home backup power.

Typical range
$5,000–$22,000
Most people pay
$12,000
Service life
20–30 years with annual maintenance; exercise and oil changes per manufacturer schedule

National cost range

National range, per installed system

$5,000 – $22,000

Most homeowners pay around $12,000. The spread is real, not hedging — the drivers below determine which end of it you land on.

Low end
$5,000
Simple access, like-for-like
Typical
$12,000
What most jobs come in at
High end
$22,000
Upgrades, difficult access, code work

What you are actually paying for

Find the row that matches your situation. Quotes that differ wildly from each other usually differ in scope, not in price.

ScenarioTypical cost
16–18 kW air-cooled, natural gas, standard installCovers HVAC, refrigerator, lights, and well pump in a typical home.$5,500–$10,000
22–24 kW air-cooled, whole-house switchThe most common full-home backup configuration.$9,000–$15,000
22 kW plus new gas line extensionGas line work is frequently the surprise cost on a first quote.$10,000–$17,000
Liquid-cooled 27–48 kW, large homeRequired when simultaneous HVAC, pool, and kitchen loads exceed air-cooled capacity.$14,000–$25,000
Propane with new 250-gallon tankCommon where natural gas is unavailable.$8,000–$16,000

What moves the price

In descending order of impact. These are also the questions worth asking a contractor whose quote sits outside the range above.

  1. Generator capacity

    A 10 to 14 kW unit covers essentials. A 22 to 24 kW unit runs most of a 2,000 square foot home including HVAC. Each step up in kW adds $1,500 to $3,000 in equipment cost.

  2. Transfer switch type

    A whole-house transfer switch replaces the main panel interface and costs more than a critical-circuits subpanel switch. Generac, Kohler, and Cummins bundle switches with their units; third-party switches vary in compatibility.

  3. Fuel source and line work

    Natural gas units need a plumber to extend the gas line — often $500 to $2,000. Propane requires a tank install or upgrade. Diesel is rare in residential.

  4. Pad, conduit, and distance from the house

    Generators must sit on a level pad, typically 5 feet from windows and doors per code and manufacturer requirements. Long conduit runs from the generator to the transfer switch add labor.

  5. Permit and utility coordination

    Electrical and gas permits are both required. The utility may need to verify gas line capacity before approving a large generator on an existing residential line.

Can you do it yourself?

Not a DIY job

Standby generator installation involves gas piping, high-amperage electrical work, and transfer switch integration with the main service. Manufacturer warranties require authorized installation. This is not a DIY project.

Permits and inspection

Electrical, mechanical, and gas permits are required. The transfer switch installation is inspected to verify it disconnects the utility before energizing the home — a failure here can injure utility lineworkers.
Run the DIY vs. pro decisionCheck a quote you already have

When this cannot wait

  • Medical equipment in the home that cannot tolerate an outage
  • Repeated multi-day outages from storms or grid failures
  • A sump pump or well pump that failed during a recent outage causing flooding or loss of water

Common questions

How much does a Generac whole-house generator cost installed?
A Generac 22 kW air-cooled unit with a whole-house transfer switch typically runs $9,000 to $14,000 installed, including the pad, gas connection, and electrical work. Gas line extension adds $500 to $2,000.
What size generator do I need for a 2,000 square foot house?
A 22 to 24 kW unit handles most 2,000 square foot homes with central HVAC, well pump, and kitchen appliances. A 16 kW unit works if you shed the HVAC compressor during an outage. Run a load calculation — do not guess from square footage.
Is a whole-house generator worth the cost?
It depends on outage frequency and consequences. In areas with regular multi-day outages or where medical equipment, sump pumps, or home-based businesses require continuity, the investment pays for itself in avoided losses. In areas with rare, short outages, a portable generator may suffice.
Does a standby generator increase home value?
In markets with frequent power outages, a permanently installed standby generator can add $3,000 to $6,000 in resale value — roughly half the install cost. In areas with reliable grids, the resale benefit is smaller.
Power out for days — what does fast whole-house generator installation cost?
A 22 kW Generac with transfer switch runs $9,000 to $14,000 installed. Rush scheduling after a major outage adds 2 to 8 weeks to wait time, not usually a price premium. A portable generator with a manual transfer switch is $1,500 to $3,500 as a faster interim solution.
Sump pump stopped during a power outage — what does a generator cost?
A battery backup sump system runs $300 to $600 installed. A portable generator with manual transfer switch runs $1,500 to $3,500. A whole-house automatic standby generator runs $9,000 to $14,000. One flooded basement remediation costs $2,000 to $10,000 — often more than the generator.
Medical equipment needs backup power — what does a home generator cost?
A critical-circuits transfer switch with a 7 to 10 kW portable generator runs $2,000 to $4,500. A whole-house 22 kW standby unit runs $9,000 to $14,000 with automatic transfer. Battery backup (Tesla Powerwall or similar) runs $12,000 to $18,000 for whole-home coverage without fuel.
How much does a Generac generator cost with installation in 2026?
A Generac 22 kW air-cooled unit with whole-house transfer switch runs $9,000 to $14,000 installed, including pad, gas line, and electrical. Gas line extension adds $500 to $2,000. Annual maintenance contracts run $200 to $400 per year.
Neighbor's generator cost less — why does mine cost more because of gas line distance?
Gas line runs cost $15 to $25 per linear foot from the meter. A 50-foot extension adds $750 to $1,250. Propane conversion adds $500 to $1,000 for tank connection. Electrical distance from the panel adds $10 to $20 per foot for conduit. Get each component quoted separately.
Is a portable generator enough, or do I need a standby unit — installed cost comparison?
Portable with manual transfer switch: $1,500 to $3,500. Whole-house automatic standby: $9,000 to $14,000. Portables require you to be home to start them and fuel them every 8 to 12 hours. Standby units start in 10 to 30 seconds automatically — the premium buys unattended operation.

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