Key insights
Generator size is the most important cost factor to consider, with 7 to 10 kW units starting around $4,500, while 22 to 30-plus kW systems can exceed $25,000.
Jump to insightInstallation costs include the generator unit, automatic transfer switch, electrical work, fuel line connections, permits, site preparation and professional labor.
Jump to insightConsider other cost factors for the most accurate price, including unit brand, fuel type, property layout and optional features for convenience.
Jump to insightWhole-house generator cost by size
One of the most influential cost factors to consider when installing a whole-house generator is the size of the generator you need. Generator size is measured in watts, and it refers to the electricity output it can handle at any given time. You should choose a generator that can provide the necessary electricity for the items you need to power during an outage.
When choosing a generator size, don’t estimate — have a professional evaluate your energy needs.
The average home needs a generator rated for 12,000 to 20,000 watts, or 12 to 20 kilowatts (kW). Usually, this standby generator size works for the average home’s square footage with standard appliances and HVAC equipment. If you have a smaller home, a large estate or special equipment, like pool pumps and heaters, you’ll need a customized fit.
» LEARN MORE: How a standby generator works
Generator size, usage and cost comparison
The table below breaks down typical generator sizes, appropriate uses and installation cost ranges to help you compare your options.
| Output (kW) | Appropriate for | Typical cost |
|---|---|---|
| 7 to 10 | Essentials only, like lighting, fridge and medical equipment | $3,650 to $10,600 |
| 12 to 20 | Whole-home coverage for an average-sized home, including HVAC equipment | $5,000 to $16,200 |
| 22 to 30 | Oversized homes, homes with multiple HVAC units or homes with electric pool heaters | $7,600 to $25,400 |
| 30 to 80-plus | Luxury estates with very high energy demands | $15,800 to $56,900 |
Whole-home generator installation cost breakdown
When you get an estimate for your whole-home generator installation, it should include everything from the materials and labor to the permit fees and site preparation. Most professionals will provide an all-in cost that may or may not include the line items below.
| Item | Typical cost |
| Generator | $3,600 to $56,900 |
| Installation labor | $1,500 to $5,000 |
| Permit fees | $80 to $500 |
| Fuel line installation | $500 to $2,000-plus |
| Site prep | $150 to $600-plus |
| Electrical panel upgrades (if necessary) | $1,000 to $2,200 |
| Automatic transfer switch installation | $500 to $2,000 |
Generator unit price
The generator itself can cost between $3,000 and $51,900, but an average-size unit will cost closer to $3,500 and $14,700. The actual price will vary depending on several factors. For example:
- Larger generators will almost always bring your total up.
- Some brands come at a higher cost than others.
- You may pay more for smart features or those with wireless control.
Installation labor cost
The labor cost to install your whole-house generator will total between $1,500 and $5,000, on average, according to Matt Kovalik, licensed Journeyworker electrician in Minnesota. Labor typically includes the following:
- Preparing and clearing the installation site
- Pouring the concrete foundation
- Mounting the generator
- Connecting the generator to your home’s electrical system
- Testing the unit
Anything that complicates the work or makes it take longer, like tree removal or breaking up existing concrete, can drive labor costs higher.
According to Kovalik, between $150 and $600 of this total will go toward pouring the concrete pad for the foundation. The remainder will go toward anchoring the unit, connecting to the electrical system and fuel source and testing.
Electrical and fuel components
A professional will need to install an automatic transfer switch (ATS), which allows for a seamless transition to backup power in the event of a blackout. They’ll also need to wire your generator to your home, install a safety ground and connect your generator to your main breaker.
Additionally, your installer will have to install a gas line to supply your generator with fuel. If you invest in a natural gas generator, they’ll need to tap into an existing gas line and route a new line to your unit. For propane, they’ll need to install a line running from your tanks to your generator.
Anything that complicates this work, such as patios, walkways or landscaping features that exist where you need to run underground gas or electrical lines, can drive costs much higher.
Permits and inspections
Anything that requires a permanent foundation or establishing a new electrical connection to your home also requires a permit. So you’ll need a permit for your standby generator. Permit fees vary based on where you live, but in most cases, permits for whole-house generators cost between $80 and $500, according to Kovalik.
You can ask your professional to determine your permit costs, or you can get the permit fee schedule from your local building department to see what the total will be.
» RELATED: Cost to replace electrical panels and wiring
Whole-house generator cost factors
There are some additional standby generator cost factors you should consider to get the most accurate estimate possible for your installation.
Generator capacity
The most influential cost factor you should consider is the capacity you need. Small generators for emergency power only can cost just a few thousand dollars, while larger generators for total coverage in a large, luxury estate can push above $50,000.
Generator brand
The brand of generator you choose can play a role in pricing, too. Major generator companies like Kohler, Champion Power Systems and Generac are usually comparable, but compare units before deciding. Consider the warranty coverage, too; a longer warranty might make a higher upfront cost worthwhile.
Fuel type
Natural gas and propane standby generators will usually have similar pricing, but the connections can vary widely. “Fuel line (installation costs) $500 to $2,000 for a gas line run, and more for a long run or a new propane tank,” said Kovalik. “This is the biggest wild card in the whole quote.”
Distance from generator to utilities
You will need electrical lines run from your unit to the main electrical panel, as well as gas lines from the unit to propane tanks or an existing natural gas line. The farther your site is from utilities, the higher your costs will be. Expect to pay more if you need trenches dug to run underground wiring or gas lines.
Electrical system upgrades
Some older homes with 100-amp electrical service may need an upgrade to 200-amp service to support a modern generator’s load. Upgrading your panel can add between $1,000 and $2,200 to your total.
Site accessibility
Anything that makes accessing your yard and installing your unit take more time will push labor costs higher. This includes heavily sloped land, nearby trees, shrubs or landscaping features and walkways, patios and other hardscaping.
Local regulations
Areas prone to flooding or seismic activity may require extra work during the installation to ensure the unit stays safe. The installer should know local requirements and abide by them, but securing and strapping a unit to resist movement during natural disasters can make the job take longer and push your labor fees higher.
Optional features
Finally, the features your generator has can play a role in your material costs. Noise reduction capabilities, smart features (e.g., remote monitoring) and maintenance alerts tend to push unit costs higher, but they can be worthwhile for the convenience and peace of mind they provide.
Also, generators usually increase your home value, and smart features can drive up that value even further.
Whole-house generator maintenance and lifetime costs
Unlike portable generators, standby generators automatically turn on for self-testing and self-maintenance at least once per week, usually for 10 to 15 minutes. This helps extend their lifespan, and it reduces the amount of hands-on maintenance you have to tackle.
However, you should schedule routine tune-ups to keep things running smoothly. This service costs between $200 and $500 per year, according to Kovalik, and it usually includes the following:
- Full inspection and load testing
- Replacement of worn components
- Replacement of spark plugs, if applicable
- Oil and filter replacements
- Battery servicing
Maintenance might seem like an unnecessary expense, but it can mean the difference between fully losing power and having the backup you need during an outage. “The number one reason a standby generator won't start during an outage is a dead battery, and it's the thing nobody checks until the power's already out,” said Kovalik.
The most common reason generators fail is a dead battery. Don’t neglect regular maintenance.
Your maintenance costs could climb higher if your unit sustains any damage or if major components break down over time. The average lifespan of a standby generator is 15 to 25 years, provided you maintain the unit properly.
An important thing to think about when estimating long-term costs is the warranty your unit comes with. A longer warranty period could save you from early repair costs. You may also want to consider purchasing a service plan for your generator, which is often available from installers and provides ongoing maintenance and inspections at a discounted price.
FAQ
What are the disadvantages of a whole-house generator?
The biggest drawback to a whole-home generator is the cost, which averages between $10,000 and $25,000 upfront, and $200 and $600 in annual maintenance. Also, whole-home generators take up yard space and can be unsightly, especially if visible from outdoor gathering areas. Finally, standby generators run for maintenance at least once a week, which can be noisy.
What size generator do I need for my home?
To size your whole-home generator, consider the appliances and systems you want to run during a blackout and calculate the power they need. You can estimate based on the wattage of your essential appliances and systems, but it’s best to have a professional come in to size your generator. This ensures you get what you need without overpaying.
Is natural gas or propane better for a whole-house generator?
It’s usually best to go with the fuel you already have on your property since this will keep costs down. If you have an HVAC system or appliances that run on natural gas, installing a natural gas generator will be more affordable, while the opposite is true if you have a propane tank on the property.
If you have neither, natural gas is usually best if you have a gas line in the street, and propane is ideal in remote areas or where natural gas isn’t available.
Is a whole-house generator worth it?
Yes, a whole-house generator can be worth it, as it can help maintain comfortable living conditions and even prevent food spoilage during power outages. A standby generator is especially worthwhile if you experience frequent outages in your area or if you or someone in your home relies on electricity for medical or life-saving equipment.
Beyond immediate comfort, a generator can also protect your home from potential damage caused by frozen pipes during winter power losses or help maintain sump pumps during storms. While the upfront investment is significant, you may find the added security and peace of mind to be invaluable, especially in regions with unpredictable weather or unreliable power grids.
Article sources
ConsumerAffairs writers primarily rely on government data, industry experts and original research from other reputable publications to inform their work. Specific sources for this article include:
- Discovery Energy, LLC dba Rehlko, "KOHLER Home Generators | Shop All Products." Accessed July 10, 2026.
- Champion Power Equipment, "Home Standby Generators." Accessed July 10, 2026.
- Generac Power Systems, Inc., "Standby Generators." Accessed July 10, 2026.