Kohler Generator Permit Requirements Guide (2025)

Kohler is one of the three major residential standby generator manufacturers — alongside Generac and Cummins — and holds significant market share in the premium segment. This guide covers what permits Kohler generator owners need, what Kohler-specific specifications matter for permit applications, and how Kohler's product line affects your local AHJ review.

Does the Brand Affect Permit Requirements?

No — permit requirements are set by your local Authority Having Jurisdiction (AHJ) and are the same regardless of whether you install a Kohler, Generac, or Cummins generator. What the brand does affect is the specific specifications your inspector will use to evaluate compliance:

• Sound rating — Kohler's residential units publish dBA ratings at specified load percentages and distances. Your inspector will compare this against local noise ordinances.
• Fuel consumption rate — Required for gas line sizing calculations on the gas/mechanical permit
• Physical dimensions — Required for setback compliance documentation (distance from structure walls, windows, property lines)
• BTU input rating — Used by the gas permit reviewer to verify adequate gas supply pressure and line sizing
• Electrical output specs — Used to size conductors and verify ATS compatibility

Popular Kohler Residential Models and Key Permit Specs

Verify all specifications on Kohler's official spec sheets before submitting permit applications — specs are updated with model revisions.

Permits Required for Kohler Generator Installations

The same three-permit structure applies to Kohler installations as to any other brand:

• Building Permit — Concrete pad dimensions, setback compliance. Kohler units require a pad sized per the installation manual (typically 2–4 inches larger than unit footprint on all sides).
• Electrical Permit — ATS installation, conductor sizing, grounding. Kohler's RXT automatic transfer switches are UL 1008 listed. Provide the ATS spec sheet with your electrical permit application.
• Gas/Mechanical Permit — Fuel line sizing, BTU load calculations. Kohler publishes BTU input ratings in each unit's installation manual.

Kohler-Specific Noise Compliance Notes

Kohler's residential units are competitive but not the quietest in the market at equivalent output levels. The 20REGAL at ~67 dBA at 23 feet can be a concern in jurisdictions with 55–65 dBA property-line noise limits (common in parts of Maryland, Connecticut, California, and the Pacific Northwest). If your local noise limit is under 65 dBA, verify that the Kohler model you're considering meets the limit at your planned setback distance before purchasing.

Noise attenuates roughly 6 dBA for every doubling of distance. A unit producing 67 dBA at 23 feet produces approximately 61 dBA at 46 feet. If your property allows greater setback, a noise-borderline unit may still comply.

Kohler's RXT Transfer Switch and Permit Documentation

Kohler's RXT series automatic transfer switches are purpose-designed for Kohler generator integration and are UL 1008 listed — which satisfies most AHJ requirements for ATS equipment. When submitting your electrical permit application, include:

• RXT spec sheet showing UL listing and amperage rating
• Installation diagram showing transfer switch location relative to main panel
• One-line diagram showing generator → ATS → panel connections
• Grounding electrode system documentation (NEC Article 250)

Is Kohler CARB-Certified for California?

Some Kohler residential generator models are CARB-certified for California — but not all. CARB certification status changes with model year revisions. Before purchasing any Kohler generator for a California installation, verify the specific model number against the California Air Resources Board's certified stationary engine list. Your Kohler dealer can provide a California-compliant model recommendation.

Recommended Transfer Switch

Submitting Your Permit Application: Kohler Documentation Checklist

When your contractor submits permit applications for a Kohler generator installation, the following Kohler-specific documents are typically needed:

• Generator installation manual — Contains pad dimensions, setback requirements, exhaust outlet location, and BTU input rating needed for all three permit applications
• Spec sheet / data sheet — One-page summary of electrical output, physical dimensions, weight, noise rating, and fuel consumption
• RXT ATS installation manual — Shows UL listing, amperage rating, and installation requirements for the electrical permit
• Site plan — Scale drawing showing generator location relative to home, property lines, windows, and doors with all setback dimensions labeled
• One-line diagram — Electrical schematic showing generator → ATS → panel connections with wire sizing

All Kohler documentation is available at kohlerpower.com or through your Kohler authorized dealer.

Kohler vs. Generac: Permit Process Comparison

Where to Find a Kohler Authorized Installer

Kohler's authorized dealer/installer network handles permit applications as part of their installation service. Find a dealer at kohlerpower.com/dealer-locator. When selecting a dealer, confirm that:

• The dealer handles all permit applications (building, electrical, gas)
• The dealer's electrical contractor is licensed in your state and municipality
• The quote is all-in including permits, labor, pad, and transfer switch
• The dealer provides a warranty on labor as well as passing Kohler's manufacturer warranty