How Much Does Whole-House Generator Installation Cost in 2025?
Installing a whole-house generator costs an average of $5,174
The average cost of a whole-house generator installation is $5,174, ranging between $1,538 and $8,821, on average, for most homeowners.
Generator capacity, brand, and installation complexity are major cost drivers for your installation.
Budgeting for maintenance is crucial to ensure long-term reliability.
Professional generator installation reduces safety risks and ensures proper setup.
This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.
Installing a backup generator costs $5,174 on average, with most homeowners paying between $1,538 and $8,821. Depending on your situation, you can pay as little as $350 or as high as $13,500 on the high end.
Generators come in various sizes, configurations, and fuel types, and each factor can influence your final costs. When you set your budget, remember to plan for routine maintenance and bring in a licensed generator installer. Professional installation protects your investment, extends the generator’s life, and gives you peace of mind.
Whole-House Generator Cost Factors
Your final generator price comes down to a handful of key details—capacity, brand, labor rates, and a few site-specific extras. Here’s how your total cost breaks down.
Capacity
Generator prices range from $500 to $18,000 based on how many kilowatts you need. Models over 30 kilowatts (kW) require liquid cooling, which adds a few thousand dollars to the base unit price compared to air cooling.
Small homes with one or two bedrooms and several appliances may need a low-end generator, costing $2,000 to $3,500. Large homes with high energy demands, like multiple refrigerators or heavy-duty HVAC, may need a 20-kilowatt or larger generator.
| Generator Size in kW | Use | Unit Cost Range |
|---|---|---|
| 1–6 | Portable backup sizes | $500–$1,800 |
| 7.5–10 | Essential and non-essential systems for homes under 1,500 sq. ft. | $2,000–$3,500 |
| 14–18 | Critical systems for homes ranging from 1,500–3,000 sq. ft. | $4,000–$5,500 |
| 20–24 | Main systems for large homes, 3,000–5,000 sq. ft. | $5,000–$6,500 |
| 26–32 | Main systems for large homes, plus additional appliances and devices | $6,500–$15,000 |
| 36–38 | Large homes with numerous high-demand appliances | $14,000–$16,000 |
| 45–48 | Large homes with numerous appliances, systems, and commercial-grade equipment | $16,200–$21,000 |
Brand
The brand you pick affects quality, reliability, available features, and the total price tag. Well-known brands like Generac or Cummins are popular among homeowners for their reliability, warranties, and customer service. They offer an array of generator models to suit various household needs.
| Brand | Starting Cost |
|---|---|
| Champion | $2,000 |
| Briggs & Stratton | $3,150 |
| Generac | $6,000 |
| Cummins | $3,700 |
| Honda | $1,310 |
Concrete Pad
Concrete pads for generators cost $50 to $75 per square foot or $1,000 total for an 18-square-foot pad. Large standby and whole-house generators are permanent installations, so a concrete pad is necessary to protect them from water and other elements that can damage internal components.
Transfer Switch
A transfer switch detects electrical disconnection and switches from the grid power supply to your generator. The National Electric Code requires these devices for safety and backfeeding prevention.
There are several types of power switches. Residential buildings use either standard manual transfer switches, which range from $500 to $2,000, or automatic transfer switches, which range from $2,000 to $30,000.
Labor
Hiring a generator installer in your area to install a permanent home generator costs between $1,500 and $5,000. While not required for portable units, installing a transfer switch and power inlet box also adds to labor costs. Most contractors charge on a per-project basis, but some contractors may add fees based on individual factors, such as:
Energy load assessment
Site preparation
Fuel tank configuration
Gas line connection
Electrical panel upgrade
Transfer switch installation
Wiring and circuits
Permits
Expect to spend $50 to $200 per permit, though local rules and your installation specs set the final number. Most homeowners need one permit for the electrical upgrade and another for the fuel line or tank.
Maintenance
Set aside $80 to $300 per year for a pro to service your generator. Scheduling a tune-up before summer and again before winter helps catch problems early and keeps the unit ready for the next outage.
Electrical Upgrades
Some generator installations require changing or upgrading your electrical panel to accommodate the additional power supply. An electrical subpanel costs $500 to $2,000 and can isolate specific circuits for essential appliances. For large-capacity generators, you may need to replace the main electrical panel to handle increased loads safely.
Enhancements
Generator enhancements can help your unit run more efficiently. Here are a few options to consider:
Wireless monitor ($200–$400): Provides remote generator status monitoring
Smart load manager ($150–$300): Creates different zones to switch the power between them
Whole-House Generator Cost by Type
Depending on the type and size, you’ll spend $500 to $25,000 for most generators.
Standby
A standby generator costs $5,000 to $25,000. These permanent installations are hardwired to your home and can automatically power your home when it doesn’t have access to grid power. Depending on your home’s power demand and the size of the generator, a standby generator can power an entire home or just critical systems, such as HVAC, refrigeration, and lighting.
Portable
Portable generators cost $500 to $2,000. They run on either gasoline or diesel and range in size. Small one-kilowatt units can power critical systems, and larger units of up to 7.5 kilowatts can power most of a home. Portable units are ideal for short-term needs because they require manual operation.
Whole-House Generator Cost by Fuel Type
The fuel type of a generator affects unit costs, installation fees, and ongoing expenses. Each fuel type has different advantages and drawbacks regarding efficiency, availability, and cost.
| Fuel Type | Average Cost Range |
|---|---|
| Natural gas | $2,000–$21,000 |
| Liquid propane | $2,000–$21,000 |
| Diesel | $3,000–$20,000 |
| Gasoline | $500–$3,000 |
| Solar | $2,000–$25,000 |
| Battery backup | $10,000–$25,000 |
Natural Gas
Natural gas generators cost $2,000 to $21,000. They’re only available as standby units because they require a permanent natural gas connection. The higher relative cost for a natural gas generator stems from its more complex fuel delivery system, but it offers superior efficiency and convenience over other types. Installation can be more costly, often requiring gas line pressure testing and generator ventilation checks.
Liquid Propane
Propane generators cost $2,000 to $21,000, and portable options average $600 to $2,600. They’re a popular option for off-the-grid and rural areas without natural gas line infrastructure. Propane generators also require setting up and storing a propane tank, ranging from $300 to $1,500, but liquid propane offers cleaner burning and has an indefinite shelf life.
Diesel
Diesel generators cost $3,000 to $20,000 for standby units. These large units are known for high efficiency and longevity but require manual refilling and sometimes have high fuel costs.
Gasoline
Gasoline generators are the most cost-effective option, at $500 to $3,000. They are mostly small and portable options, and gas is readily available in most regions. However, high gas prices and shorter shelf life can make them less economical.
Solar
Solar generators cost $2,000 to $25,000 for most homes. Most whole-home units cost $10,000 or more and involve installing solar panels. Portable solar generators are compact units with a built-in solar panel array, inverter, and battery to store generated power. They range from $1,500 to $5,000.
Small units can’t store large amounts of energy. Modern solar technology allows most units to produce power even during overcast days, although efficiency depends on the quality of solar equipment and your specific climate.
Battery Backup
A battery backup costs $10,000 to $25,000 for whole-home units. Fuel costs depend on whether you’re pulling from the grid or a solar array, but it’s an economical and sustainable backup option.
Costs depend on the quality of the battery and other features. For example, some backup batteries automatically prioritize charging during off-peak grid rates to save costs.
Does Installing a Whole-House Generator Increase Home Value?
A standby generator often boosts home value—especially in areas that see frequent outages or severe weather. The added convenience, comfort, and security appeal to future buyers, and they’re essential for households that rely on medical equipment.
Budgeting for a Whole-House Generator
Get the most from your investment and streamline your costs with these budgeting tips for whole-house generators:
Collect at least three quotes from local generator installers so you can compare equipment and labor costs.
Match the generator size to your home’s load—buying extra capacity only drives up the bill.
Ask generator installers about off-season deals or limited-time promos to trim expenses.
Look for fuel-saving features that help you cut operating costs over the long haul.
How HomeAdvisor Gets Its Cost Data
No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. We surveyed thousands of real customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Frequently Asked Questions
Plan on professional maintenance once a year. In between visits, follow the owner’s manual for oil changes, air-filter swaps, spark-plug checks, and battery tests. Drain gasoline if the unit will sit for months, and run the generator briefly every few weeks to keep parts lubricated. At the first sign of trouble, book a repair visit so minor issues don’t spiral into major damage.
With regular service, a quality standby generator can run for 30 to 50 years—or roughly 3,000 hours of standby power. Limit any single run to 500 hours or less to avoid excess wear. Pairing the unit with an extended warranty and sticking to yearly maintenance protects performance and keeps your investment working when you need it most.
A whole-house generator delivers reliable power, keeps critical systems online, and can raise resale value. It’s a smart add-on if you work from home, experience frequent outages, store perishables, use medical devices, or rely on a sump pump. During a blackout, the unit switches on automatically so you stay comfortable, productive, and safe.
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