How Much Does It Cost to Install a Generator Transfer Switch in St. Louis, MO? [2026 Data]

Generator transfer switch installation costs in St. Louis, MO, range from $1,141 to $1,522. The average homeowner pays around $1,379 on this project. The risk of thunderstorms and ice storms in the city, where power outages are likely, makes a generator with a transfer switch a good option. As you prepare for this project, include these costs in your budget.

Generator Transfer Switch Installation Cost Factors

Generator transfer switch installation costs in St. Louis, MO, are determined by the generator's size. The type of transfer switch installed will also affect the price. Automatic switches have a higher installation cost than manual switches.

Size of Generator Transfer Switch

Depending on the size of your generator, you’ll need a transfer switch of the same capacity and ampacity to keep your St. Louis, MO home running during an emergency. Here’s how the cost is impacted by generator size in watts:

Type of Generator Transfer Switch

An automatic generator switch is more expensive than a manual switch. Here’s how the two compare:

Amp Requirements

As the amp requirement increases, the cost of the generator transfer switch will also rise. That’s because higher-amperage switches use stronger parts and better materials to safely handle the extra electricity, which makes them more expensive to manufacture.

Number of Circuits

Multi-circuit transfer switches get more expensive as the number of circuits increases. That’s because more circuits mean more hardware and wiring inside the box, and they can also make installation more labor-intensive. For example, a six-circuit switch might start around $200, while a 16-circuit unit often costs $1,000 or more.

Existing Electrical

To ensure your electrical panel is up to code, your electrician may need to upgrade your electrical panel or subpanel, or install new circuit breakers, before installing a generator transfer switch. Here’s what you might pay for each task:

Permits

The average cost for a generator transfer switch permit is between $47 and $333. While obtaining a permit for a portable generator isn’t usually necessary, installing a whole-home generator requires a permit for electrical upgrades.

Generator Transfer Switch Installation Pro Costs

Generator installation pros in St. Louis, MO, charge an average of $75 to $108 per hour. Mechanical permits are required for generator transfer switch installations in the city at a cost of $77, which covers inspection and plan review. Your St. Louis, MO, generator pro will handle obtaining your project permits.

Does Installing a Generator Transfer Switch Increase Home Value?

Yes, homeowners will see an increase in home value after installing a whole-home generator with a transfer switch. The average increase is between 3% and 5%. Severe storms, including thunderstorms and ice, in the area can cause frequent power outages, and potential buyers will view a transfer switch as a source of peace of mind.

How Angi Gets Its Local Cost Data 

To help homeowners plan their next project, Angi provides readers with carefully researched cost data and upholds strict editorial standards. We start with national average project costs, which we collect by analyzing competitor information, retailer material costs, and input from professional contractors. We then apply local price index data to calculate location-specific estimates that reflect what homeowners typically pay in their local area. To do that, we use data from the U.S. Bureau of Economic Analysis (BEA), including its Regional Price Parities (RPPs), which measure price differences across cities. This helps us account for differences in labor, materials, and overall cost of living, so estimates in higher- or lower-cost areas better reflect real-world local pricing.

Every estimate undergoes a thorough editorial review to verify accuracy, consistency, and alignment with observed market conditions.

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