Can I wire my guest bathroom on one circuit?

Question

I am remodeling a small bathroom attached to a guest bedroom and I am wondering if I can wire the whole thing on one branch circuit.

The bathroom is divided into two parts:

a 5x5 room, behind a door, with just a toilet and a shower. This part has an overhead LED light and a wall-mounted fan.

just outside the 5x5 room, a sink with a mirror. This part has two wall-mounted lamps, one on each side of the mirror, and a GFCI receptacle.

Can all of this be wired safely and code-compliant on one circuit? Would I use 12 AWG wire throughout, and a GFCI breaker at the panel?

Thanks!

Answer 1

Yes, in the US under the NEC you can wire a single bathroom on a 20A circuit, provided that circuit feeds ONLY loads within that one bathroom. This circuit cannot be shared with other rooms or other bathrooms.

This is not to say this is best practice, but it can be done.

210.11 Branch Circuits Required

(C) Dwelling Units.

(3) Bathroom Branch Circuits.

In addition to the number of branch circuits required by other parts of this section, at least one 20-ampere branch circuit shall be provided to supply bathroom receptacle outlet(s). Such circuits shall have no other outlets.

Exception: Where the 20-ampere circuit supplies a single bathroom, outlets for other equipment within the same bathroom shall be permitted to be supplied in accordance with 210.23(A)(1) and (A)(2).