New addition to house is 576 square feet total - master bedroom, bathroom, walk in closet, house entry foyer, and porch. Here's my plan.

  • 15amp dedicated circuit for fire alarm
  • 20amp dedicated circuit for bathroom receptacles
  • 20amp circuit for rest of outlets in addition
  • 20amp circuit for 2 outdoor outlets on porch. I will be plugging my camper into these sometimes
  • 15amp circuit for all lights. will include: 2 recessed lights on porch, ceiling fan on porch, 2 wall sconces on porch, ceiling fan in bedroom, 5 recessed lights in bedroom, 2 light fixtures in closet, light fixture in foyer, exhuast fan in bath, 6 horizontal lights in bath over mirrors, 1 main light fixture in bath.
  • 1
    Don't you want to go ahead and wire up a 30A circuit or even a subpanel for the camper? Future upgrades... I'd probably put the outdoor lights on a different breaker.
    – JPhi1618
    Jun 11, 2019 at 19:14
  • How far away is the water heater? Point of use tankless for the master would be nice, and require a large circuit.
    – JPhi1618
    Jun 11, 2019 at 19:16

4 Answers 4


I have also been advised to include some lights on the smoke & fire detector circuit, in order to give you some indication if the smoke & fire has gone offline. I believe Ed Beal's comment about 760.41.b refers to dedicated fire alarm panels, and that residential detectors are considered receptacles.

I found this https://www.electriciantalk.com/f5/smoke-detector-circuit-72368/ which addresses the question.

Of course it's always best to check with your local building department for the final say.



With that many lights, I would split them into two circuits. That way if there is a problem with a light fixture tripping a breaker, or even just to be able to work on a fixture safely by turning off a breaker, you are not totally in the dark.

Bathroom Fan

I recommend a separate 20A circuit for the bath fan. That will allow you to upgrade to a heater/fan combination later without running new wires. You can combine that with some of the bathroom lights, though I would not combine it with "all" the bathroom lights so that you don't lose all the lights if there is a problem with that circuit.


Bathroom circuits. Make it two per bathroom. That way you can use more than one hair appliance at once. The ladies of the house will thank you!


Move some of the lights to the fire alarm circuit. It lightens the load of the other lighting circuit and you then have an incentive to keep it on rather than just turning it off at the breaker and or possibly not noticing that the breaker tripped without you knowing.

Whether you can do this depends on local code though.

  • 1
    See 760.41.b branch circuits for fire alarm equipment shall supply no other loads. So this advice would be a code violation.
    – Ed Beal
    Jun 19, 2019 at 13:43
  • 1
    @EdBeal there are jurisdictions where fire alarms are allowed to share a circuit with other stuff. OP didn't specify his location on the globe. Jun 19, 2019 at 20:31
  • @EdBeal -- that only applies to NFPA 72 protected premises systems; multiple station smoke detectors are not "fire alarms" for the purposes of Art. 760 Jul 16, 2019 at 22:39

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