circuit ? regarding addition
 

so i am putting up a 20x40 addition that is 2 rooms and a full bath. i am trying to determine the minimum cicuits out of panel required. i know i need a dedeicated circuit for the bathroom. can i use a circuit for lights and receptacles or is there a formula for number of lights and receptacles for a circiut? outdoor hvac condensor. i think i only need 3 total but maybe not.......

What are the rooms to be used for?
1 circuit for the bathroom receptacles and lights.
1 circuit for each room, and whatever requirmnts the hvac needs.
Thats how I would do it.

living room
sitting (reading)room
bathroom
i was wondering if 1 circuit should be to each room or not.

You could do both rooms on 1 circuit.

in all fairness the reading room will likely turn to a bedroom in future if that matters- not now so no arc fault needed
permit is as listed for living, sitting, bath

Not sure of local codes but shouldnt receptacles be 20A + 12Ga, and lighting be 15A + 14Ga?

So then combine all lights on one circuit, all receptacles on another, and HVAC on 3rd dedicated.

Most of this other than the 20 amp ckt for the bath is personal preference.

Mine:

20 amp-- bath
15 amp -- lights in both rooms
15 amp -- receptacles in both rooms

HVAC as required

Bathroom gfci receptacle(s) 20 amp circuit. Can also be used for bathroom lighting but I prefer not to. The bathroom fan/lights can be on a lighting circuit with other rooms but the other rooms cannot be on the 20 amp bathroom receptacle circuit.
15 amp lighting circuit can be used for all of the lighting in the rooms but I would calculate what the total load will be for all of the lights. 15 or 20 amp circuit for the receptacles in the other rooms. If the load is light as in a bedroom/reading room I prefer to use 15 amps for the receptacles. HVAC condenser will likely be 240 volt and will require a dedicated circuit.