Whole House Generator Cost: What You'll Actually Pay in 2026
Last updated: July 5, 2026
Quick Answer: A whole house generator cost typically falls between $7,000 and $20,000+ fully installed, depending on the generator's size, your home's fuel setup, and local labor rates. Most homeowners with a mid-size home (2,000 to 3,500 sq ft) spend between $10,000 and $15,000 for a complete standby system from a brand like Cummins or Briggs & Stratton, including the unit, transfer switch, concrete pad, permits, and labor.
Key Takeaways
- Whole house standby generator costs range from roughly $7,000 to $20,000+ installed, depending on size and site conditions
- Generator size (measured in kilowatts) is the single biggest driver of unit price, most homes need between 13kW and 22kW
- Installation costs include labor, a transfer switch, a concrete pad, permits, and fuel line work, these add $3,000 to $7,000 on top of the unit price
- Standby generators run on natural gas or propane and start automatically during an outage, no manual setup required
- Annual maintenance typically runs $200 to $400, and fuel costs vary by runtime and fuel type
- Cummins and Briggs & Stratton are two of the most reliable standby generator brands available today
- Permits are almost always required and should be factored into your budget from the start
- Financing options are available through dealers and third-party lenders, making upfront cost more manageable
Table of Contents
- How Much Does a Whole House Generator Cost?
- Whole House Generator Cost Installed: The Full Breakdown
- What Size Generator Do You Need for Your House?
- Whole House Generator Installation Cost: What's Actually Included
- Portable vs. Standby Generator: Which One Is Right for You?
- Do You Need a Permit for a Whole House Generator?
- How Long Do Whole House Generators Last?
- Whole House Generator Maintenance Costs
- Whole House Generator Fuel Costs Per Year
- How Much Does It Cost to Run a Generator for a Week?
- Best Whole House Generator Brands
- Whole House Generator Financing Options
- FAQ
- Conclusion
How Much Does a Whole House Generator Cost?
The honest answer is that whole house generator cost depends on three things: how much power your home needs, what your site requires for installation, and where you live. For most homeowners, the total investment lands between $7,000 and $20,000, with the sweet spot for a properly sized standby system sitting around $10,000 to $15,000 fully installed.
That range sounds wide, but it narrows quickly once you know your home's square footage, your existing fuel source, and whether you need a new transfer switch. The unit itself is only part of the picture.
Here is a general cost overview by generator size:
| Generator Size | Unit Price (Estimate) | Typical Home Size |
|---|---|---|
| 13kW | $3,500 - $5,000 | Up to 1,500 sq ft |
| 16kW | $4,500 - $6,500 | 1,500 - 2,500 sq ft |
| 20kW | $5,500 - $8,000 | 2,500 - 3,500 sq ft |
| 22kW+ | $7,000 - $11,000+ | 3,500+ sq ft or high loads |
These are unit prices only. Add installation costs on top of these figures [4].
Whole House Generator Cost Installed: The Full Breakdown
When people search for "whole house generator cost installed," they want the real number, not just the sticker price on the box. The installed cost is what matters, and it includes several components beyond the generator itself.
Here is a realistic cost breakdown for a standard residential standby installation:
| Cost Component | Typical Range |
|---|---|
| Generator unit (13kW - 22kW+) | $3,500 - $11,000 |
| Automatic transfer switch | $700 - $1,500 |
| Concrete pad | $300 - $800 |
| Installation labor | $1,500 - $3,500 |
| Electrical work | $500 - $1,500 |
| Gas line extension or propane setup | $300 - $1,500 |
| Permits and inspections | $100 - $500 |
| Total installed estimate | $7,000 - $20,000+ |
A few things push costs higher: long gas line runs, older electrical panels that need upgrades, difficult terrain around the installation site, or high local labor rates. A few things keep costs lower: existing natural gas service close to the installation point, a newer electrical panel, and straightforward site access.
The takeaway here is simple. Budget for the full installed cost from day one. The unit price alone will not tell you what you will actually spend.
What Size Generator Do You Need for Your House?
Most homes between 1,500 and 3,500 square feet need a generator in the 16kW to 22kW range to power essential systems and major appliances simultaneously. Smaller homes with modest electrical loads can work with a 13kW unit. Larger homes, homes with electric HVAC, or homes with well pumps and multiple large appliances should look at 20kW or higher.
To size your generator accurately, an installer will typically look at:
- Your home's total square footage
- Whether you have central air conditioning (one of the biggest loads)
- Electric vs. gas appliances (stove, water heater, dryer)
- Whether you have a well pump or sump pump
- Any medical equipment or home office equipment with continuous power needs
A common mistake is undersizing to save money upfront. A generator that cannot carry your full load will either trip or force you to manually shed loads during an outage. That defeats the purpose of having a standby system.
Choose a 13kW unit if: You have a smaller home, gas appliances, and want to cover essentials only.
Choose a 16kW to 20kW unit if: You have a mid-size home with central air and a mix of gas and electric appliances.
Choose 22kW+ if: You have a large home, all-electric appliances, a pool pump, or high continuous loads.
For a more detailed walkthrough, use our home standby generator sizing guide to match your exact load to the right kW size.
Whole House Generator Installation Cost: What's Actually Included
The whole house generator installation cost covers more than just dropping a unit in your yard and flipping a switch. A proper installation is a multi-trade job that typically involves an electrician, a plumber or gas technician, and sometimes a concrete contractor.
Here is what a complete installation typically includes:
- Site preparation: Clearing and leveling the area, pouring a concrete pad for the generator to sit on
- Transfer switch installation: The automatic transfer switch connects to your main electrical panel and switches your home to generator power within seconds of an outage
- Electrical connections: Running wiring from the transfer switch to the generator
- Fuel line connection: Tapping into your natural gas line or setting up a propane tank and regulator
- Load testing: Running the system under load to confirm everything operates correctly
- Permit filing and inspection: The installer pulls the permits and coordinates the inspection
A full installation from a licensed contractor typically takes one to two days for a standard residential job. More complex installs with panel upgrades or long gas line runs may take longer.
Portable vs. Standby Generator: Which One Is Right for You?
A standby generator starts automatically, runs on natural gas or propane, and requires no action from you during an outage [1]. A portable generator must be manually started, runs on gasoline, and requires you to be home and physically set it up. For whole-house coverage, standby is the clear choice.
Here is a direct comparison:
| Feature | Standby Generator | Portable Generator |
|---|---|---|
| Startup | Automatic | Manual |
| Fuel | Natural gas or propane | Gasoline |
| Power output | 13kW to 22kW+ | Typically 3kW to 10kW |
| Whole-home coverage | Yes | Partial, with limitations |
| Installation required | Yes | No |
| Upfront cost | $7,000 - $20,000+ installed | $500 - $3,000 |
| Long-term convenience | High | Low |
Portable generators make sense for occasional, short-term use or for powering a few circuits. If you want power that shows up when it counts, without you having to do anything, a standby system is the right investment.
Do You Need a Permit for a Whole House Generator?
Yes, in almost every jurisdiction, you need a permit to install a standby generator. Permits cover the electrical work, the gas line connection, and the generator placement itself. The National Electrical Code requires listed transfer equipment specifically to prevent backfeeding power onto utility lines, a hazard to line workers restoring service [2]. Skipping permits is not just illegal in most areas, it can also void your homeowner's insurance coverage and create problems when you sell your home.
Your installing contractor should handle the permit process as part of the job. If a contractor tells you permits are not necessary or offers to skip them to save money, that is a red flag.
Permit costs typically range from $100 to $500 depending on your municipality. Factor this into your total budget from the start.
How Long Do Whole House Generators Last?
A well-maintained standby generator from a quality brand like Cummins or Briggs & Stratton will typically last 20 to 30 years with regular service. These units are built for long-term residential use, not occasional weekend duty.
The key to longevity is consistent maintenance. Generators that are serviced annually, have their oil and filters changed on schedule, and are exercised regularly (most modern units do this automatically) will reach the top of that range. Neglected units fail sooner.
Whole House Generator Maintenance Costs
Annual maintenance for a standby generator typically costs between $200 and $400 per service visit from a qualified technician. This covers an oil change, filter replacement, spark plug inspection, battery check, and a full system test.
Some homeowners handle basic maintenance themselves, but an annual professional inspection is worth the cost. It catches small issues before they become expensive failures, and it keeps your warranty valid.
Over a 20-year lifespan, you might spend $4,000 to $8,000 on maintenance, which works out to a modest ongoing cost for a system that protects your home year-round.
Whole House Generator Fuel Costs Per Year
Fuel costs depend heavily on how often the grid fails in your area. Standby generators run a brief weekly self-test (usually 10 to 20 minutes), which consumes minimal fuel. Actual outage runtime is what drives annual fuel costs.
Estimates for natural gas consumption on a 20kW generator run roughly 150 to 200 cubic feet per hour at full load. For most homeowners in areas with occasional outages, annual fuel costs for the self-test cycles and a few real outages might total $50 to $150 per year on natural gas.
Propane costs more per unit of energy than natural gas, so propane-fueled systems will see higher fuel bills, especially in areas with frequent or extended outages.
How Much Does It Cost to Run a Generator for a Week?
Running a 20kW natural gas generator continuously for a full week at moderate load (roughly 50 to 75% capacity) would consume an estimated $150 to $300 in natural gas, based on average residential gas rates. Propane costs would be higher, potentially $400 to $700 for the same period, depending on local propane pricing.
These are estimates based on typical consumption rates and average fuel costs. Your actual cost will vary based on your generator's size, your load, and your local fuel rates.
For most homeowners, even a week-long outage represents a manageable fuel cost compared to the alternative of spoiled food, hotel stays, or business disruption.
Best Whole House Generator Brands
Two brands consistently stand out for residential standby generators: Cummins and Briggs & Stratton.
Cummins has built its reputation on commercial and industrial power systems for over a century. Their residential standby line brings that same engineering discipline to home backup power. Cummins units are known for quiet operation, durable engines, and strong dealer support networks.
Briggs & Stratton has a long history in small engine manufacturing and has applied that expertise to a solid line of residential standby generators. Their units offer competitive pricing, reliable performance, and good parts availability.
Both brands offer units in the 13kW to 22kW+ range that cover the full spectrum of residential needs. Both are built for real situations, not best-case assumptions. Browse the full standby generator lineup to compare models side by side.
Whole House Generator Financing Options
Most generator dealers, including certified Cummins and Briggs & Stratton dealers, offer financing options that spread the cost over 12 to 60 months. Some manufacturers offer promotional financing through their dealer networks, including low-interest or deferred-interest plans for qualified buyers.
Beyond dealer financing, you can also explore:
- Home improvement loans through your bank or credit union
- Home equity lines of credit (HELOC) if you have available equity
- Personal loans for borrowers who prefer not to use home equity
- Utility rebate programs in some states that offset installation costs for backup power systems
Financing makes standby generator ownership accessible without a large upfront payment. A $12,000 installed system financed over 48 months at a reasonable rate might cost $250 to $300 per month, which many homeowners find manageable compared to the cost of a single serious outage.
FAQ
Q: What is the average whole house generator cost for a 2,000 square foot home?
A: For a 2,000 square foot home with central air and typical appliances, expect to spend $10,000 to $14,000 fully installed for a 16kW to 20kW standby generator. This includes the unit, transfer switch, concrete pad, labor, and permits.
Q: Can I install a whole house generator myself?
A: Not practically, no. Standby generator installation involves licensed electrical work, gas line connections, and permit-required inspections. Most jurisdictions require a licensed electrician and a licensed plumber or gas technician. Attempting a DIY install can void your warranty, fail inspection, and create serious safety risks.
Q: How long does a whole house generator installation take?
A: A standard residential installation typically takes one to two days. More complex jobs involving panel upgrades, long gas line runs, or difficult site conditions may take three to four days.
Q: Does a whole house generator add value to my home?
A: Yes. A permanently installed standby generator typically adds 2 to 3% to a home's resale value, with returns on the original cost ranging from 50 to 150% depending on your market [3]. Buyers in storm-prone areas often view it as a significant selling point.
Q: What fuel type is better for a whole house generator, natural gas or propane?
A: Natural gas is generally preferred where it is available because it is delivered continuously through a utility line, so you never run out during a long outage. Propane is a good alternative where natural gas is not available, but you need to maintain an adequate tank supply and monitor fuel levels.
Q: How often does a standby generator need to be serviced?
A: Once per year is the standard recommendation for most residential standby generators. Service includes an oil and filter change, spark plug inspection, battery check, and a full operational test. Some manufacturers recommend more frequent service if the unit sees heavy use.
Conclusion
Whole house generator cost is a real investment, and it deserves a clear-eyed look before you commit. The numbers are straightforward once you understand what drives them: generator size, site conditions, fuel setup, and local labor rates. For most homeowners, a fully installed standby system from a quality brand lands between $10,000 and $15,000. That covers a unit sized for your home, a proper transfer switch, a concrete pad, permits, and professional installation.
The more important question is not what it costs. It is what it costs you not to have one. A week without power means spoiled food, potential pipe damage in cold climates, lost remote work productivity, and in some cases, genuine safety risks for people who depend on medical equipment or climate control.
A standby generator from Cummins or Briggs & Stratton is power you can rely on. It starts automatically. It runs on a continuous fuel supply. And it keeps your home running whether you are there or not.
If you are ready to get a real number for your home, request a quote from Mighty Generators. We carry Cummins and Briggs & Stratton standby generators and can connect you with a certified installer in your area. Tell us your home size, your fuel type, and what you want to protect, and we will help you find the right system at the right price. Browse our full standby generator collection to get started.
Request your free generator quote today and get power that shows up when it counts.
References
- Briggs & Stratton. "PowerProtect Standby Generators." energy.briggsandstratton.com
- Reliance Controls. "Transfer Switch Kits and NEC Article 702 Requirements." reliancecontrols.com
- Angi. "Is a Whole House Generator Worth It?" angi.com
- HomeGuide. "How Much Does a Whole House Generator Cost?" homeguide.com
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