Generator Checklist
Per 2023 NEC (National Electrical Code), Effective March 31, 2025
Generator Checklist Submittal Requirements
All construction drawings must be submitted in PDF format at the time of your online building permit application:
Site Plan – Equipment Outside a Building
- Show the location of the generator and distance to adjoining property lines and buildings.
- Show the location of the fuel tank or gas hookup at the house. If a new fuel tank is proposed, provide the tank size and dimension the distances to the parcel boundaries. Note: Fuel tanks must be placed out of the setbacks.
- Show the location of all electrical service equipment and transfer switch.
- Show clearances of the equipment.
- If a new propane tank is necessary and not included as part of the generator application, then the new propane tank will require a separate permit.
- If a new propane tank is needed, a separate building permit is required.
Wiring Requirements
Load calculations as per Article 220 for automatic transfer systems. If calculated loads exceed the listing of the generator, load shedding provisions will be required.
Provide a one-line diagram for generator and electrical service that includes the following information:
- Conductor sizes
- Conductor insulation types (i.e., THHN, THWN, direct burial cable, etc.)
- Conductor material (i.e., copper/aluminum)
- Conduit sizes
- Conduit material (i.e., non-metallic, EMT, etc.)
- Overcurrent device ratings
Provide product information:
- Include the proposed generator size in KW, type of fuel source, and whether system is an automatic transfer switch or manual transfer switch, portable of fixed.
- Product listing sheet for the generator, transfer switch, load shedding devices, and, if applicable, diesel fuel tanks.
Note: The manufacturer’s installation instructions must be on-site for inspections.
If you have any questions, please email: building@bouldercounty.gov
Mechanical Equipment and Electric Generator Installations shall not exceed noise limitations as regulated in the Colorado Revised Statutes or the Boulder County Ordinances regulating noise limitations including, but not limited to, Noise Ordinance 1992-28. Installations shall comply with the most restrictive requirement.
Note: Boulder County Noise Ordinance #1992-28 section 1.01.050, C. Sound from a non-vehicular source located in a residential area, shall not exceed the following limits:
7 a.m. – 7 p.m. of the same day: 55 dB(A)
7 p.m. – 7 a.m. of the following day: 50 dB(A)
Definitions, exemptions, and additional requirements are outlined in #1992-28.