The size of the job depends on what the building will do. A few lights and outlets is a modest project. A woodshop with table saws, dust collection and a heater calls for a subpanel and a properly sized feeder.
Feeders, Subpanels and Detached Buildings
For light use, a single branch circuit from the house may be enough. For heavier use, an electrician typically installs a feeder to a subpanel in the shop, which then supplies several circuits inside. Detached buildings also need their own grounding arrangement, and the rules for separating neutral and ground at a subpanel are different from the main panel.
Getting power across the yard is usually done underground. The required burial depth depends on the wiring method (direct-burial cable, PVC conduit or rigid metal conduit) and on whether the circuit has GFCI protection. Driveways, roots, rocks and other buried utilities all affect the route, so the trench plan is worked out before digging begins. Call 811 before any digging so buried lines can be marked.
Projects That Need Power at an Outbuilding
A new shed needs lights and a couple of outlets.
You are turning a backyard building into a woodworking or hobby shop.
A detached studio or office needs heating, cooling and outlets.
A barn or equipment building needs lighting and power for tools.
An old overhead line to a shed is sagging or damaged.
Signs the Existing Shed Power Is a Problem
- An extension cord runs across the yard as permanent power.
- Shop tools trip the breaker or lights dim when saws start.
- The shed has no GFCI protection or disconnect.
- An overhead wire to the building rubs against tree limbs.
- Outlets or boxes in the shed show rust, moisture or pest damage.
What a Shed or Shop Project Involves
The electrician plans the load, chooses the feeder size and wiring method, maps the trench route and decides whether a subpanel is warranted. Permits are typical, and inspectors often want to see the trench before it is backfilled.
- Expected tool, lighting and heating or cooling load
- Main panel capacity and breaker space for the feeder
- Burial depth and wiring method for the run
- Subpanel, disconnect and grounding at the building
- GFCI protection for outlets in the shed
- Route around driveways, roots and marked utilities
How it usually works
Call about your outbuilding
Describe the building, distance from the house and how you plan to use it. The call connects you with an independent local electrician.
Load and route planning
The electrician sizes the feeder, chooses a wiring method and maps the trench or overhead route.
Trenching and installation
The feeder is installed, inspected if required, and the subpanel or disconnect and inside wiring are completed.
Final testing
Circuits, GFCI protection and grounding are tested before the building is put to use.
For homes around Chattanooga
Rural homes around Chattanooga often have wells, barns and detached shops, and hillside lots with mature trees can make both trenching and overhead runs tricky. Homes on the plateau and in the Sequatchie Valley tend to have longer runs between buildings. For attached spaces, see garage electrical work instead.
