Cost to Install a Generator – 2021

| Last Updated: August 24, 2021

National Average Improvement and Repair Cost







$ 7700

$ 5400

Would you do this project? According to our survey, 48% of respondents preferred DIY compared to hiring a pro.

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The average price to Install a Generator noted above is cost data to compare a contractor’s estimate with doing it yourself.

How much does it cost for a generator? The cost of having a home backup generator installed is $7,700. Don’t think about doing this job yourself. 

A standby generator is designed to keep the appliances and systems of a house working when there’s a power outage. When the power goes, the lights go out, the food in the refrigerator and freezer begins to spoil, and there’s no way to charge electronic devices. You can’t even access your car if it’s parked in a garage with an electric garage door opener.

A standby generator is located outside and wired directly to the house through a transfer switch. Loss of power starts the generator and connects it to the house wiring. The most economical units to purchase and run are in the 20 kilowatt (kW) range and fueled with natural gas or propane. This size will power specific circuits you choose like the refrigerator, heating unit, and lights, but will not be a substitute for the power company.

A professional will install a 20 kW Generac Synergy unit with a variable speed motor for $7,700. This includes wiring the transfer switch and hooking up a propane or natural gas line. You can purchase the generator and transfer switch for $5,400 and save $2,300 or 29 percent.

While the cost difference is significant, don’t be tempted by the potential savings. In most areas, you are required to get a building permit, which usually comes with some sort of inspection. Most of the work requires a licensed electrician and a plumber to hook up the gas line. To honor the warranty, most manufacturers require a trained tech do the initial startup and checkout. Most of these costs are included in the professional installation.

Welcome! We hope you’ll find the job costs of home improvement projects useful when you’re deciding whether to do a job yourself vs. hire a contractor. We’re the authors of 20 home improvement books, most notably Home Improvement for Dummies©, Bathroom Remodeling for Dummies©, Carpentry for Dummies©, Plumbing for Dummies©, and Painting and Wallpapering for Dummies©. Our most recent book Fix It and Flip It is in its second edition. We’ve appeared as home improvement experts on television programs such as CNN, Dateline, the Today Show, HGTV and many others.