Adding a Subpanel to a Garage or Workshop in DFW: Cost, Amps & What You Actually Need

If you're powering a woodshop, welder, EV charger, or detached ADU, a subpanel is almost always the answer. Individual circuits are a code and budget disaster past 3–4 loads.

Which Size Subpanel Do You Need?

| Load Profile | Recommended Subpanel |

| --- | --- |

| Light workshop (lights, outlets, small tools) | 60A |

| Woodshop or car garage (dust collector, compressor, EV charger) | 100A |

| Detached shop or ADU (HVAC + all above) | 125A |

| Full ADU (kitchen, HVAC, W/D, mini split) | 125A – 200A |

Real DFW Install Cost (2026)

| Scope | Typical Cost |

| --- | --- |

| 60A subpanel, attached garage, short run | $1,650 – $2,400 |

| 100A subpanel, attached garage | $2,200 – $3,200 |

| 100A subpanel, detached (30–60' underground) | $3,500 – $5,500 |

| 125A subpanel, detached w/ trench | $5,000 – $7,500 |

| 200A subpanel to ADU (underground w/ conduit) | $7,500 – $12,000 |

What Drives Cost

4. Grounding electrode system at detached buildings (needs its own ground rod)

The 4-Wire Rule for Detached Buildings

Since the 2008 NEC, detached structures require a 4-wire feeder (2 hot, 1 neutral, 1 ground) with grounds and neutrals isolated at the subpanel. This is the #1 code violation we see when re-inspecting DIY jobs.

Permits in North Texas

We handle all permits and inspections.

What Gets Under-Bid

Get a Real Subpanel Quote

We do a load calc, measure the feeder run, and give a fixed price with the permit included. Call (817) 447-7141 or [request a subpanel quote](/get-a-quote).