sandyman720

Hello,

I am adding an addition to the back of my house with a half bath. I plan to have a couple of receptacles, overhead lights, and fan in the room. On the outside I plan to have 2 lights on each side of the door. Then in the bath i plan to have a receptacle, light and exhaust fan.

By code, how many circuits does this have to be on? Can I get away with one circuit? What size breaker?

I think I have to use 12/2 romex for the bath? If so and it is all on one circuit, does all the other wiring have to be 12/2?

Thanks!

redline

At least one circuit for the bath and one or two for the other items depending on the use.

Stubbie

Code requires 20 amps for bathroom receptacles and they must be gfci protected. You have two options you can supply just the receptacles in the bathroom with twenty amps or you can supply both the receptacles and the other utilization items (fan and lights) in that bathroom, but that circuit can serve no other rooms just the one bathroom. If you choose to supply just the bathroom receptacles with 20 amps then you cannot by code supply anything outside the bathroom with that 20 amp circuit other than another bathrooms receptacles. You need to take into account what is going to be operated at one time in that bathroom. One hair dryer or two at the same time. If two 1500 watt hair dryers or a 1500 watt curling iron and 1500 watt hair dryer then you should look at bringing two 20 amp circuits to the bathroom receptacles. Put the bathroom exhaust fan and light one a 15 amp circuit with the other rooms lights.
If only one of these at a time then one 20 amp will suffice. Place the bathroom lights and exhaust fan on the 20 amp circuit with the bathroom receptacles. There may be some dimming of the lights with this configuration when the hair dryer is turned on. At the gfci box connect the lights and fan to the line side of the gfci. It is not required to supply gfci protection to those items. In this screnario the load terminals of the gfci should not be used unless you are going to have another receptacle in the bathroom in which case supply it from the load terminals of the gfci. It does not have to be the gfci type in order to have gfci protection. Just install a regular grounding type duplex receptacle and use the gfci upstream by wiring to its load terminals to protect it.
In the room if you plan on using a vacuum sweeper supply the receptacles with 20 amps. If not a few receptacles on a 15 amp circuit is just fine. My advice is to put the receptacles on a 20 amp circuit. As for the lights I ,generally, ...if panel space allows... use 15 amp circuits. I would catch the lights and exhaust fan in the bathroom on this circuit also if I elected to just run a 20 amp to the bathroom receptacles only. I dont like lights on the same circuit with receptacles whenever I have a reasonaable choice not to do so. This eliminates the dimming effect on lights when you start up a 15 amp vacuum cleaner or high amp hair dryer. So to condense..... assuming the new room is not a bedroom,

OPTION 1 ... (bathroom receptacles on a 20 amp circuit by themselves)

Bathroom light and exhaust fan on 15 amp circuit along with lights in other room.
Room receptacles along with the ceiling fan on a 20 amp circuit. I'm assuming here that the fan is a ceiling fan. If it has a light dome but you have other lights in the room any dimming of the ceiling fan lights shouldnt be bothersome.
Total new circuits 3...one 20 amp for bathroom receptacles, one 15 amp for lights in both rooms and exhaust fan and one 20 amp for room receptacles and ceiling fan. Maybe only 2 new if you can tap an existing circuit for the receptacles and ceiling fan.

OPTION 2... (One 20 amp circuit supplying everything in the one bathroom)... as long as loads on the 20 amp circuit are reasonable.

One 15 amp circuit for ceiling fan and lights in other room. One 20 amp circuit for receptacles either tapped from existing or new circuit.

Total new circuits 3 or possibly 2 new if you can tap another circuit for the receptacles and ceiling fan.

I'm not a fan of combing too many room lights on one breaker in the event of a tripped breaker or partial power loss in the circuit. You need to be able to see so you dont want to lose too many lights if a problem occurs.

Stubbie

tribe_fan

Always check the local building dept - sometimes there are codes you may want to be aware of -sometime they are nice and will give you some tips that are common mistakes that a DIYer would make.

- minimum distance between receptacles
- a light switch at each entrance ( in my case two - controlled by three way switches
- a hard wired smoke detector (that one surprised me)

If this is going to be a family room - you wont regret having enough receptacles. Also consider running cable for TV's. You never know where the wife will want to put the TV.