Whole Home Generator Installation: What Every Homeowner Needs to Know Before They Buy

A whole home generator is a desirable piece of home equipment. Who doesn’t want the luxury of regaining power moments after an outage in a heavy storm? But this investment can be as expensive as it is enticing, with current whole house generator cost estimates ranging from $8,000 to $15,000 or more. Let’s run through everything you need to know before you commit.

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Whole Home Generator vs. Portable Generator: What’s Actually Different

Whole home generators and portable generators both provide power during local outages, but they are otherwise very different machines. A portable generator is a smaller piece of equipment with a more limited power output. When your home loses power, you can manually start the generator and use some extension cords to connect it to a few essential appliances, such as the refrigerator, space heater, and a couple of lamps. Most portable generators are fueled by gasoline and need to be operated outdoors because they emit carbon monoxide.

A whole home generator, or standby generator, is a larger machine that sits permanently on a concrete pad behind or to the side of the house. Unlike a portable generator, it is hardwired to the home’s electrical panel with an automatic transfer switch, which enables the generator to switch on as soon as there’s an interruption in utility power. There’s no wrangling of extension cords or manual intervention needed. Just wait 15 seconds or so for the generator to power up, and it’s as if the outage never occurred.

Whole home generators are usually fueled by either natural gas or propane. A natural gas generator requires a dedicated gas line. This eliminates the need to manually refuel, but it’s not an option for every home. Propane generators don’t rely on local infrastructure and can be installed virtually anywhere, but they require an on-site tank that you need to refuel periodically.

What to Think About Before Buying a Whole Home Generator

Installing a standby generator is a substantial financial investment, and asking a few questions ahead of making a purchase can help you avoid costly rework or buyer’s remorse. Here’s what to consider:

• How much power do you need?

Whole home generators range in capacity, with smaller models delivering an output of 10 to 14 kW and larger models delivering 26 kW or more. The greater the capacity, the more expensive the generator. Before committing to a particular model, you’ll need to consider both your home size and what you want to supply with power during an outage.

• What fuel will you use?

A natural gas generator is most convenient if you already have a gas line running to your property. If you don’t, a propane generator is the most common alternative. This will require a fuel tank in addition to the generator itself, and a 250- or 500-gallon tank takes up additional space in the yard. Some generators use diesel or solar batteries, but these are less common.

• Where will you place the generator?

Manufacturers and local governments may have minimum clearance requirements to keep a generator some distance away from the house, windows, doors, and property lines. Proximity to gas lines and the electrical panel are also considerations.

• Are there any municipal or HOA regulations?

Due diligence when exploring whether to install a standby generator also entails checking your town or HOA rules. Some locations and organizations restrict where a generator can be placed or how loud it can be.

• Is your electrical panel compatible with a standby generator?

Your electrical panel’s compatibility with a standby generator isn’t a given. Older panels or small panels may need to be upgraded before they can accommodate an automatic transfer switch.

What a Whole Home Generator Installation Entails

Installing a whole home generator is a multistep process that will take several days to weeks. Here is what to expect:

• Load calculation. A licensed installer will measure your home’s electrical demand based on the size of your house and personal preferences. This figure will determine how much power you need from your generator and its fuel demands.
• Property survey. The next step is to assess your home and property to determine placement options for the generator. There may also be an electrical inspection to confirm your home’s electrical panel and system are compatible with a standby generator.
• Permitting. Before work begins, your installer or contractor will pull any permits that your jurisdiction requires.
• Foundation preparation. A generator needs some kind of foundation, which is typically a concrete pad that is prefabricated or poured on site.
• Gas line or fuel tank installation. If you’re installing a generator fueled by natural gas, a plumber or gas fitter will need to run a gas line. If you’re going with a propane generator, you’ll need to install a fuel tank beside the machine.
• Electrical wiring. With all of the planning and infrastructural work taken care of, an electrician can connect the generator to your home’s electrical system via the automatic transfer switch.
• Testing and inspection. Finally, your installer can simulate an outage to test the generator. Most places also require a final inspection to confirm the installation is up to code.

How Much a Whole Home Generator Installation Actually Costs

Doing a quick search online for generator prices won’t give you the full picture of installation costs. Other factors push the overall cost for most homeowners to between $8,000 and $15,000 or more. Let’s break it down.

• Generator: The cost of the actual generator is dependent on its size, but most residential units range from around $3,000 to $6,000+.
• Automatic transfer switch: Depending on the model and amperage, an ATS can range from $500 to nearly $2,000. 
• Electrical labor: Wiring the ATS to the home’s electrical panel and performing any necessary electrical updates could add an additional $600 to $1,500.
• Fuel infrastructure: If a natural gas line is required, expect to pay $10 to $25 per linear foot. This cost can inflate if the line has to cross a paved driveway. For a propane generator, the tank and install could range from $700 to $2,500.
• Concrete pad: A prefabricated concrete pad will cost $200 to $800.
• Permits and inspection fees: $50 to $500, depending on your municipality.

How to Maintain a Whole Home Generator So It’s Ready When You Need It

Part of the draw of a standby generator is its automatic operation, but it still requires maintenance and upkeep to ensure it’s functional when you need it. Here are some essential generator maintenance tasks to fold into your home maintenance checklist:

• Test the generator on a biweekly schedule to circulate the oil and confirm overall functionality.
• Test the battery annually and consider replacing the battery every 3–5 years.
• Keep the generator clean of leaves, twigs, and other debris. Trim back branches and shrubs, and promptly clear off snow.
• Change the oil and filters every year or after you exceed around 200 hours of use.
• Schedule annual service checkups so that a qualified tech can inspect the transfer switch, fuel pressure, and battery.

Also be sure to check on your generator if it’s been running for more than a few days due to a prolonged outage. You may need to change the oil or schedule an inspection earlier than anticipated.