A workshop wants several circuits: tools, a compressor, lighting, maybe a charger. Running each one back to the main panel is the expensive way to get there. One feeder and a subpanel at the building is almost always the cheaper one.
proper burial depth and a disconnect at the building
every circuit labelled at both ends
Why one feeder wins
Garage and shop wiring: one feeder beats four runs
Every circuit taken back to the main panel is a separate run, a separate breaker position and a separate length of cable, which is the same arithmetic outlet and switch installation sets out for a single device.
A subpanel at the building solves both. It runs $400 to $1,800 as a component, and everything the shop needs lands there with short branch runs instead. Figures are example ranges. Subpanel installation covers the grounding arrangement, which differs from the main panel and is one of the most common faults in work done without inspection.
The load calculation still governs. Where the service genuinely cannot carry the addition, an electrical panel upgrade comes into it, but that is a different problem from a panel that is simply full and is priced differently.
Fresh install
How it runs
Garage wiring in Buffalo, four steps
List what goes in
Tools, compressor, lighting, charger, heating. The list sizes the feeder, and it is worth including what is not bought yet.
Load calculation
Whether the service carries the addition. A full panel and an undersized service are different problems at different prices.
Trench and feed
Correct depth, direct burial cable, and a disconnect at the building. Anything else going underground shares the dig.
Land, label, inspect
Short branch runs from the subpanel, labelled at both ends, then inspected with the certificate to you.
Detached buildings
On garage and shop wiring, the trench cannot be redone
A feeder to a detached building needs correct burial depth, the right cable for direct burial, and a disconnect at the far end so the building can be isolated from the building. None of those are optional and all of them are invisible once backfilled.
That is also the moment to combine anything else going underground. A level 2 charger run to the same building, or outdoor lighting along the same route, costs a fraction inside the same dig.
Inside the shop, plan the positions before the walls go up. Outlets at bench height, enough of them, and a circuit that is not shared with the lighting so a tripped tool does not leave you in the dark. Outlet and switch installation covers deciding placement while it is still cheap.
Usually yes, and it is the cheaper answer. Four separate runs back to the main panel cost more in cable and labour and fill four positions you probably do not have.
Correct burial depth, cable rated for direct burial, and a disconnect at the far end so the building can be isolated at the building.
Sized for the shop you will have rather than the one you have. The extra capacity costs a little more cable now; upsizing later means digging again.
Yes. A tripped tool should not leave you standing in the dark holding it, and separating them costs almost nothing at rough-in.
Yes, and it should if one is likely. One dig serving two purposes is a fraction of the cost of two.
Yes, if the feeder was sized for it. Tell us what you intend to run before the feeder is chosen, because upgrading it later means the trench again.
