I've attached a rough sketch of our house layout. My question is about the room labeled with a "?". Would the NEC consider this a "dining room", even if there isn't any typical dining room furniture - that is, no dining room table/chairs, no buffet/sideboard, no dish/china storage, etc? (We have a couch, a piano, and a desk in there.) It's largely open to what we call the "living room", with an open doorway to the kitchen. All walls are full ceiling height. The kitchen has a small table (like a breakfast nook) in it where we usually eat, when we're not eating in the living room in front of the TV, or outside on the back patio. We don't have any room in particular that we use as a "dining room", but if a future owner were to have a dining room, this "?" room would most likely be it.
The question arises because the NEC requires 20 amp circuitry in a "dining room", per 210.52(B) below. The house is currently wired such that that entire "?" room is served by one (dedicated) 15 amp circuit, with 14/2 wiring and a 15 amp breaker, for all the receptacles and lighting in that room.
(The kitchen does have the 2 required 20amp small appliance circuits.)
EDIT to clarify: the house is about 100 years old; the 15amp circuitry is already in place (an has been for decades). There are some wiring updates happening - addition of a couple of receptacles. I know I can just ask the inspector, but... I'm afraid to even raise the issue, in case he never raises it either. :)
I believe the 2014 NEC says the following:
210.52 Dwelling Unit Receptacle Outlets.
(B) Small Appliances.
(1) Receptacle Outlets Served. In the kitchen, pantry, breakfast room, dining room, or similar area of a dwelling unit, the two or more 20-ampere small-appliance branch circuits required by 210.11(C)(1) shall serve all wall and floor receptacle outlets covered by 210.52(A), all countertop outlets covered by 210.52(C), and receptacle outlets for refrigeration equipment.
EDIT to add: After reading the answers below... I still don't know if the room is even required to be classified as a "dining room" (which was my original question), but if it is, then I guess that if I want to add 2 wall receptacles to that room, code would require hooking them up to one of the existing 20-amp kitchen circuits, rather than hooking them up to the existing 15-amp circuitry in that room.
Or just keep everything as is and continue using extension cords as we have been. (Safe? No. Compliant? Yes.)
It's funny that the reason we want to add receptacles of course has nothing to do with "dining room" purposes; we just want a convenient outlet for an audio system and a computer. Tying those in to the kitchen circuitry seems absurd, as does installing a new 20-amp circuit just for those outlets. But oh well. Maybe somebody someday will want to put a hot plate in that room, and boy will they thank me for having put in a couple of 20-amp outlets! (Even though they're not required to be labeled as such. Go figure. Here's hoping they don't plug the hot plate into the wrong outlet, or the breaker will trip. Heavens! I can see why the NEC can't allow that!)