--- title: Detached Structure Electrical: How to Run a Proper Service to a Workshop, Garage, or Barn description: Planning a shed, workshop, or barn electrical hookup in [sa_city]? Learn what a proper detached structure electrical service really takes — and why it matters. url: https://fhrelectric.com/detached-structure-electrical-how-to-run-a-proper-service-to-a-workshop-garage-or-barn date_modified: 2026-07-12 author: language: en_US --- So you’ve got a detached garage, a workshop behind the main house, or maybe a barn out past the pool — and you want real power out there. Not a 50-foot extension cord snaked through the grass. Actual that’s permitted, inspected, and built to last. Here in , we see this project come up constantly, and almost every time a homeowner calls us, they’ve already gotten one bad quote from someone who skipped half the steps. Let’s walk through what this actually involves so you know exactly what you’re buying. ## Why a Detached Structure Isn’t Just a Long Extension of Your Panel A detached structure — even a modest workshop — is treated by the NEC as a *separate building*. That means it needs its own disconnect means at the structure, its own grounding electrode system, and in most cases its own subpanel. This isn’t bureaucratic red tape; it’s the reason the lights in your house stay on if something trips in the shop. The separation also protects you during a ground fault, which matters a lot in where monsoon moisture can find its way into outbuildings that nobody waterproofed carefully. If your panel is already loaded — and a lot of homes in are running 20-year-old 200-amp panels that are genuinely maxed out with EVs, new HVAC, and kitchen upgrades — you may need a [panel upgrade](https://fhrelectric.com/services/electrical-panels-power-upgrades/electrical-panel-upgrades/) before we even start pulling wire to the outbuilding. We check that first so there are no surprises mid-project. ## Underground or Overhead? Choosing the Right Feed Method ![A licensed electrician installing a subpanel for a detached structure electrical service inside a timber-framed workshop in a Scottsdale backyard](https://fhrelectric.com/wp-content/uploads/2026/07/avathan-6a53c3e7814bc.jpg "Detached Structure Electrical: How to Run a Proper Service to a Workshop, Garage, or Barn") The two methods for getting power from your main house to a detached structure are aerial (overhead) and underground (direct-burial or conduit). In and throughout Maricopa County, underground is almost always the better choice — aesthetically and practically. Here’s how they compare: - **Underground in conduit:** Cleanest look, best protection, required by most municipalities for runs longer than a few feet. Minimum burial depth is 24 inches for rigid metal or Schedule 80 PVC under NEC 300.5. This is what we recommend the vast majority of the time. - **Direct-burial cable (UF-B):** Lower material cost, but still requires 24 inches of cover in most cases and offers less protection from accidental dig-through. Acceptable for shorter, simpler runs. - **Overhead service:** Permitted where clearance requirements can be met (typically 10–18 feet depending on what passes beneath). Rarely the right call in a finished yard, but occasionally practical for agricultural parcels in the East Valley or Fountain Hills. > The permit and inspection step isn’t optional — it’s what stands between a clean certificate of occupancy and a problem that surfaces at resale. Every detached structure electrical service we install in gets pulled with a proper permit. ## Sizing the Service: Don’t Guess, Calculate ![A licensed electrician installing a subpanel for a detached structure electrical service inside a timber-framed workshop in a Scottsdale backyard](https://fhrelectric.com/wp-content/uploads/2026/07/avathan-6a53c3ef8ec9d.jpg "Detached Structure Electrical: How to Run a Proper Service to a Workshop, Garage, or Barn") This is where most DIY plans fall apart. People think a 30-amp feed is fine until they plug in a table saw, a compressor, and a shop vac at the same time and pop a breaker 40 feet away from the panel. Size your detached structure electrical service for what you’ll actually run, not just what you run today. Common starting points: - **60-amp subpanel:** Light workshop use — power tools, lighting, a single mini-split. Good entry point for a basic shed electrical hookup. - **100-amp subpanel:** The sweet spot for most serious workshops and detached garages. Handles a welder, compressor, EV charger, and HVAC simultaneously without straining the feed. - **200-amp subpanel:** Barn conversions, accessory dwelling units, or any structure that functions like a second home. Also right for a detached garage that needs a [Tesla charger installation](https://fhrelectric.com/services/ev-chargers-smart-home-low-voltage/tesla-charger-installation-services/) plus heavy tools and climate control. We size the wire gauge to match the breaker and the distance — voltage drop over long runs is real, and undersized wire to a 100-amp panel 150 feet from your house is a problem that shows up as heat, not as a tripped breaker. If you want to read the underlying NEC guidance, the [NFPA 70 (National Electrical Code)](https://www.nfpa.org/codes-and-standards/nfpa-70-standard-development/70) is the governing document — it’s worth knowing exists even if you’re not reading it yourself. ## What a Proper Workshop Electrical Service Looks Like Inside the Structure Once the feed is in and the subpanel is mounted, the interior rough-in is where you future-proof the space. For most workshop and detached garage wiring projects in , we recommend: - GFCI protection on all receptacles (required by NEC in garages and outbuildings) - [Dedicated circuits](https://fhrelectric.com/services/electrical-panels-power-upgrades/dedicated-circuits/) for any fixed equipment — compressors, welders, dust collectors - At least one 240V circuit roughed in even if you don’t need it yet - Exterior-rated weatherproof outlets on the outside walls - LED shop lighting on its own circuit so a tool load doesn’t dim your workspace If you’re thinking about running Cat6 for a camera system or Wi-Fi access point in the shop, our [network cabling installation](https://fhrelectric.com/services/ev-chargers-smart-home-low-voltage/network-cabling-cat6-cat7-installation/) team can handle that in the same visit — one trench, one project. Homeowners near McCormick Ranch or up in North Scottsdale with larger properties often ask about adding a whole-home generator connection at the same time. That’s a conversation worth having before we backfill the trench — retrofitting is always more expensive than planning ahead. Take a look at our [whole-home generator backup power](https://fhrelectric.com/services/backup-power-generators/whole-home-generator-backup-power/) options if that’s on your radar. The cost for a detached structure electrical service in the area typically runs $1,800–$6,500+ depending on distance from the main panel, service size, conduit type, and interior finish-out. That’s a real range, not a lowball to get you on the phone. Every project is scoped individually after we see the site. If you want it done once and done right — permitted, inspected, and backed by a licensed Arizona contractor with over 20 years in the Phoenix metro — call at . We’ll come out, look at the site, and give you a straight number before any work starts. [Call at](tel:(602) 492-9999)