Yes — running electricity to a detached shed or garage almost always requires an electrical permit in Denver and across Colorado. This is true whether you’re adding a simple 20-amp circuit for a few outlets or installing a full subpanel with multiple circuits, 240-volt service, and lighting. The permit triggers an inspection by your local jurisdiction’s building department, and that inspection confirms the work is safe — correct wire sizing, proper grounding, weatherproof connections where required, and appropriate protection from physical damage.

Why This Work Requires a Licensed Electrician

In Colorado, electrical work that requires a permit must be performed by a licensed electrical contractor. This isn’t red tape — it’s recognition that running power to a detached structure involves real hazards: buried underground feeder cable, weatherproof outdoor connections, proper load calculations, and a subpanel that’s correctly bonded and grounded. A mistake in any of these areas can result in a shock hazard, a fire, or equipment damage. An unlicensed DIY installation that later causes a fire or injury can also affect your homeowner’s insurance coverage.

What the Project Typically Involves

Most detached garage and shed electrical projects follow a similar path. A circuit originates at your main panel, runs through underground feeder cable (typically in conduit, depending on depth and local code), and terminates at either a subpanel in the structure or at a dedicated circuit if the power needs are modest. The subpanel approach gives you flexibility — you can add circuits inside the garage for lighting, a compressor outlet, a welder receptacle, EV charging, or a mini-split — without having to run multiple separate underground runs from the house.

  • Underground feeder cable must be buried at the correct depth — typically 24 inches for direct burial or 6 inches in rigid conduit, though local amendments may vary
  • The feeder size depends on how much load you plan to run — a 60-amp subpanel handles most garages; larger shops may need 100 amps
  • The subpanel must have its own ground rod (or rods) at the structure — it cannot share the ground from the main panel
  • GFCI protection is required for outdoor and garage receptacles under current NEC code
  • If you’re adding EV charging, a 240-volt Level 2 charger circuit needs to be sized and positioned correctly from the start

Planning Ahead Saves Money

The most common mistake homeowners make with garage electrical is under-planning. Running a single 20-amp circuit to a shed seems adequate until you want to add a second outlet, a ceiling light, a heater for Colorado winters, or an EV charger. The trenching and underground work is the most labor-intensive part of the job — doing it once and installing a subpanel with room to grow is almost always more cost-effective than coming back to do it again later.

Tell your electrician what you plan to do in the space — now and in the future. A woodworking shop, a home gym, EV charging, a 240-volt welder, a mini-split for heat and cooling — each of these has different electrical requirements, and knowing upfront allows us to size the feeder and subpanel correctly on the first trip.

What Done Handles for You

Done’s licensed electricians pull the permit, handle the trench work coordination, install the underground feeder, set the subpanel, wire the circuits, and schedule and pass the final inspection. You don’t need to manage the permit office or be present for the inspection — we handle it. When the job is done, you have a completed permit card and documented, code-compliant electrical in your outbuilding.

To discuss your shed or garage electrical project, contact Done or explore our panel and wiring services. If EV charging is part of the plan, see our EV charger installation page. Our full electrical services cover everything from the subpanel to the individual outlets and fixtures inside the structure.