For some reason I have it in my head that there is a section in the NEC which prevents the use of anything smaller than 20A circuits to supply multiple general purpose receptacles.
While I know for certain that the use 20A circuits to supply residential multiwire circuits is common convention and a requirement for some outlets in kitchens, laundry rooms, and bathrooms (sections from 210.11 of the 2014 NEC quoted below), I cannot seem to find a section in the NEC which prohibits the use of 15A circuits to supply multiple general purpose receptacles in other areas of the house. This is not to say I plan to deviate or am advocating deviating from this convention for circuits which supply multiple receptacles, I would just like to confirm whether I somehow tricked myself into thinking it is actually required by the NEC or if it is really just a good common convention.
From NFPA-70:2014 (2014 NEC)
210.11 Branch Circuits Required.
…
(C) Dwelling Units.
(1) Small-Appliance Branch Circuits. In addition to the
number of branch circuits required by other parts of this
section, two or more 20-ampere small-appliance branch circuits
shall be provided for all receptacle outlets specified by
210.52(B).(2) Laundry Branch Circuits. In addition to the number
of branch circuits required by other parts of this section, at
least one additional 20-ampere branch circuit shall be provided
to supply the laundry receptacle outlet(s) required by
210.52(F). This circuit shall have no other outlets.(3) Bathroom Branch Circuits. In addition to the number
of branch circuits required by other parts of this section, at
least one 120-volt, 20-ampere branch circuit shall be provided
to supply a 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).
Best Answer
In the US under the NEC in a residential setting there is no prohibition for a 15A general use receptacle circuit. You are correct in that some areas; kitchens (and similar/associated rooms), laundry, bathrooms, do require 20A receptacle circuits, but there is nothing that prohibits 15A receptacle circuits in most other places.