Installing a whole-home standby generator is a multi-trade project that involves a licensed electrician, a plumber or gas technician, your utility company, and your local building department. The full process typically takes one to three days of installation work, plus lead time for equipment and permits. Here is a summary of what each phase involves so you know what to expect.

Site Assessment and System Sizing

Before anything is ordered or installed, a technician will assess your home’s electrical load to determine the right generator size. Whole-home generators are rated in kilowatts, and the right size depends on whether you want to power every circuit in the house simultaneously or just the essential ones. In Colorado, typical whole-home applications include the furnace or heat pump, refrigerator, well pump (if applicable), lighting, and some outlets — with larger systems also running central AC, water heaters, and EV chargers.

The site assessment also covers placement: generators must be positioned a specific distance from windows, doors, and gas meters per local codes, and they need to be accessible for annual maintenance. Colorado’s deep freeze winters and heavy wet-spring snow should factor into pad placement and clearance planning.

Permits and Utility Coordination

Whole-home generator installation is permitted work in Colorado. Your contractor pulls permits from the local jurisdiction before work begins, and the installation is inspected after completion. If the generator connects to natural gas, the gas line work is also inspected. Some jurisdictions also require coordination with the utility company, particularly when an automatic transfer switch is involved, to ensure the generator cannot back-feed power onto the utility grid.

The Installation Steps

A standard whole-home standby generator installation involves these major steps:

  • Pouring a concrete pad (or placing a composite pad) where the generator will sit
  • Running a dedicated gas line from your meter to the generator location (or propane tank installation if natural gas is not available)
  • Installing an automatic transfer switch (ATS) at or near your main electrical panel — this is what detects an outage and switches the home to generator power automatically
  • Running electrical conduit and wiring from the panel to the generator
  • Setting and connecting the generator unit
  • Starting up, testing, and commissioning the system
  • Scheduling and passing the required inspections

What the Automatic Transfer Switch Does

The automatic transfer switch is the brain of a whole-home generator system. Within seconds of detecting a grid outage, it disconnects your home from the utility line and connects it to the generator — all without you touching a switch. When utility power is restored, the ATS switches back and the generator shuts itself down. This is what distinguishes a standby generator from a portable generator: standby units work even when you’re not home, which matters enormously during Colorado’s winter storms and wildfire-season power disruptions.

Post-Installation Maintenance

Standby generators run a brief self-test weekly to ensure they’re ready to operate. Beyond that, they need annual maintenance — oil and filter changes, spark plug inspection, battery check, and a load test — similar to a small engine. Skipping maintenance is the most common reason generators fail to start during the actual outage they were purchased to handle. Done’s team can set you up with a maintenance schedule to keep your system reliable year after year.

If you’re considering a whole-home generator for the Denver Front Range, start with a conversation about load sizing and fuel type. Done’s team will walk you through standby vs. portable options, natural gas vs. propane, and what your existing panel can support. Visit our backup power and generator installation page for details, or explore panel and wiring services if your current panel may need upgrading to support the transfer switch. Questions about cost? See our financing options.