How Much Does a Whole-House Generator Cost in Denver?

A whole-house generator for a Denver home typically costs between $5,000 and $20,000 fully installed, depending on the size of the unit, the brand, and how much electrical work your home needs before the generator can go in. Most Denver homeowners land somewhere in the middle of that range for a system sized to keep a typical single-family home running through a Colorado power outage.

At Top Shelf Electric, Heating, & Plumbing, we install whole-house generators throughout Denver Metro and Colorado Springs, and we know the first question every homeowner asks is some version of “what’s this actually going to cost me?” Here’s a real breakdown of what drives the price — and what you can do to keep it reasonable.

What Determines the Cost of a Whole-House Generator?

Four factors do most of the work in determining your final price:

• Generator size (kW rating). A 22kW system — the most common size for a 2,000–3,000 square foot home — sits in the middle of the price range. Smaller homes can often get by with less; larger homes or those wanting to run central air conditioning during an outage need more.
• Brand and equipment tier. Generac is the most widely installed home standby generator brand in the country, but Kohler, Cummins, and Briggs & Stratton are all common alternatives with their own price points and warranty structures.
• Electrical panel condition. If your existing panel can’t support a transfer switch without an upgrade, that adds to the project — and it’s one of the most common surprises homeowners run into partway through a quote.
• Fuel type and site work. Natural gas hookups, propane tank placement, concrete pad requirements, and how far the unit sits from your panel all affect labor time.

Typical Price Ranges by Scenario

Based on typical installations across the Denver market:

• Installation labor alone (not including the generator unit): roughly $5,000–$10,000
• A common 22kW system, fully installed with permits: approximately $10,000–$13,000
• Larger systems or homes needing panel upgrades: can run $15,000–$20,000 or more

These are market-wide ranges, not a quote — the only way to get an exact number for your home is an in-person assessment, since panel condition and site layout vary house to house.

Ways to Manage the Cost

A few things genuinely move the needle on price:

• Right-size the system. Bigger isn’t always better — an oversized generator costs more upfront and to maintain without adding real protection for most homes.
• Ask about financing. Top Shelf partners with Wells Fargo Home Projects and Greensky to offer 0% interest financing on approved credit, which spreads the cost out without adding to it.
• Time it outside storm season. Installers are busiest right before winter storms and summer heat waves — scheduling in the off-season can mean more flexibility on timing, if not always on price.

Frequently Asked Questions

How long does generator installation take?

Most residential installations take one to two days once the equipment is on-site, though permitting timelines can add a week or more before work begins.

Do I need a permit to install a generator in Denver?

Yes. Generator installations typically require both electrical and building permits. Top Shelf handles all permitting and inspection scheduling as part of every installation.

What size generator do I actually need?

Sizing depends on your home’s square footage, your electrical panel’s capacity, and which circuits you want to keep running during an outage — everything from just the essentials (fridge, sump pump, furnace) up to whole-house coverage including central air.

Get a Real Number for Your Home

Ranges are a starting point, not a quote. Top Shelf Electric, Heating, & Plumbing provides free in-home assessments for generator installation throughout Denver Metro and Colorado Springs, with upfront pricing and no surprises once the work begins. Request a quote or call (720) 899-2633 to get started.