Kohler Standby Generator Permit Requirements
Same requirements as any standby generator. Kohler brand generators require the same building, electrical, and mechanical permits as Generac, Cummins, or any other brand. The permit requirement is triggered by the type of installation — not the manufacturer.
Kohler is the second-largest residential standby generator brand in the U.S., known for their quieter liquid-cooled models and their industrial-heritage reliability. This guide covers Kohler-specific permit considerations, noise data by model, and what makes Kohler installations different from Generac installs from a permitting standpoint.
Kohler Residential Models and Permit Requirements
| Model Series | kW Range | Type | Noise (dBA @ 7m) | Permits Needed |
|---|---|---|---|---|
| RES Series (air-cooled) | 8–20 kW | Air-cooled | 65–67 dBA | Building + Electrical + Gas |
| RESAL Series (air-cooled) | 20 kW | Air-cooled | 67 dBA | Building + Electrical + Gas |
| RESCL Series (liquid-cooled) | 20 kW | Liquid-cooled | 65 dBA | Building + Electrical + Gas |
| RCL Series (liquid-cooled) | 30–60 kW | Liquid-cooled | 64–66 dBA | Building + Electrical + Gas; may need structural review |
Kohler vs. Generac: Key Permit Differences
From a pure permitting perspective, Kohler and Generac installations are nearly identical — same three permits, same NEC requirements, same inspection process. The practical differences:
- Kohler transfer switches: Kohler uses their own RXT series automatic transfer switches, which are separately listed and separately submitted as part of the electrical permit. Some Kohler models include the ATS; others require it to be specified and quoted separately.
- Kohler pad requirements: The RES/RESAL series are similar in footprint to comparable Generac units. The liquid-cooled RCL series are longer — up to 103 inches for larger units — which affects concrete pad dimensions and setback calculations.
- Kohler's quieter liquid-cooled advantage: In noise-sensitive jurisdictions (Connecticut, Massachusetts, Northern Virginia, Seattle), Kohler's 20RESCL at 65 dBA is often preferred over comparable air-cooled units specifically for noise ordinance compliance.
- Dealer network: Kohler sells through an authorized dealer network similar to Generac. Kohler dealers are required to pull permits as part of the installation — same as Generac's program.
Kohler Noise Data for Permit Applications
Many building departments and HOA applications require manufacturer noise documentation. Here are Kohler's published ratings:
| Model | kW | dBA @ 7m | Type | 60 dBA Compliant? | 65 dBA Compliant? |
|---|---|---|---|---|---|
| 8RESVL | 8 | 65 | Air | ⚠️ Marginal | ✅ Yes |
| 12RESVL | 12 | 65 | Air | ⚠️ Marginal | ✅ Yes |
| 20RESAL | 20 | 67 | Air | ❌ No | ⚠️ Marginal |
| 20RESCL | 20 | 65 | Liquid | ⚠️ Marginal | ✅ Yes |
| 30RCL | 30 | 65 | Liquid | ⚠️ Marginal | ✅ Yes |
| 48RCL | 48 | 64 | Liquid | ⚠️ Depends on lot | ✅ Yes |
Kohler Concrete Pad Dimensions
| Model | Unit Dimensions (L×W×H) | Recommended Pad Size | Weight |
|---|---|---|---|
| 8–12 RESVL | 48" × 27" × 29" | 54" × 36" | ~370 lbs |
| 20RESAL / 20RESCL | 60" × 29" × 37" | 72" × 42" | ~500 lbs |
| 30RCL | 82" × 33" × 44" | 90" × 42" | ~840 lbs |
| 48RCL | 103" × 35" × 53" | 114" × 48" | ~1,400 lbs |
FAQ
Does a Kohler generator require a permit?▼
Yes — every Kohler standby generator installation requires permits. Typically: a building permit for the pad and placement, an electrical permit for the transfer switch and panel connections, and a mechanical permit for the gas line. Kohler's authorized installers are required to pull all necessary permits as part of the installation program.
Is the Kohler 20RESCL quieter than the Generac 22 kW?▼
Yes — the Kohler 20RESCL (liquid-cooled) rates at 65 dBA vs. the Generac 22 kW air-cooled at 68 dBA. That 3 dB difference is meaningful in noise-sensitive jurisdictions. If your local ordinance caps at 65 dBA, the liquid-cooled Kohler may be compliant where the air-cooled Generac requires mitigation.
Use our Permit Checker for a custom permit list, or Size Calculator to pick the right generator first.
Disclaimer: Requirements vary by jurisdiction. Always verify with your local building department before beginning any installation work.