How to Install a New Electrical Outlet in a Garage

Garages are notoriously short on power, leaving most homeowners balancing the needs of power tools, shop vacs, and vehicle chargers on a single overloaded circuit. Adding a new outlet is the single most effective way to reclaim your workspace, provided you follow the electrical codes specifically designed for unfinished, high-impact environments. Working in a garage often means you are dealing with open stud bays or concrete walls. Because code typically requires exposed electrical wiring in garages to be protected from physical damage, you will use metal conduit or armored cable rather than standard plastic-sheathed wire. Done well, this installation is permanent, safe, and keeps your cables organized and clear of snag-prone tools.

  1. Kill the Power First. Go to your main electrical panel and switch off the breaker controlling the area where you intend to work. Use a non-contact voltage tester on existing outlets to confirm the power is dead before touching any wiring.
  2. Level and Secure the Box. Secure a surface-mount metal utility box directly to a wall stud using wood screws. Position the box at a comfortable working height, typically 48 inches above the floor for garage workbenches.
  3. Run Protected Conduit. Measure and cut your metal conduit to run from the power source box to your new junction box. Secure the conduit to the wall studs using metal pipe straps every 3 feet.
  4. Thread the Wires Through. Feed THHN wire (black, white, and green) through the conduit from the source box to your new outlet box. Leave 8 inches of excess wire at both ends for making your connections.
  5. Wire the GFCI Outlet. Strip the ends of the wires and attach them to the GFCI outlet: black to the brass screw, white to the silver screw, and green to the green ground screw. Ensure all connections are tight and no stray wire strands are touching other terminals.
  6. Verify It Works. Fold the wires neatly into the box, screw the GFCI outlet into place, and attach the faceplate. Turn the power back on and test the receptacle with a plug-in circuit tester to confirm proper wiring.