If one wants to add a new receptacle on the second floor in a finished room with no receptacles the easiest method appears to be doing the wiring in the attic.
Drill top plate in the attic.
I want to pass some conduit up into the attic space over the room for speaker and network cable.
One hole hole on the wall above the sub panel to get access to the top plate see where the wires are and get your wire fished into the top or back of the panel depending how its mounted.
However this would require one to drill one hole through the top plate in order to get the wire from the desired receptacle location into the attic.
I ve been reading the irc 2015 and the wording for drilling into top plates isn t clear.
Normally you would cut out an access hole in the plaster below the top plate and drill a hole through the top plate.
Just go up in the attic pull back the insulation and find the top plates.
If you will need to fish wiring through a wall drill a hole through the wood plate in the attic only.
When piping or ductwork is placed in or partly in an exterior wall or interior load bearing wall necessitating cutting drilling or notching of the top plate by more than 50 percent of its width a galvanized metal tie not less than 0 054 inch thick 1 37 mm 16 ga and 1 1 2 inches 38 mm wide shall be fastened across and to the plate at each side of the opening with not less than eight 10d 0 148 inch diameter nails having a minimum length of 1 1 2 inches 38 mm at each side or.
I did this recently to run ethernet cable in an exterior wall.
The photo at left shows a typical one flush drywall on one side and a big gap on the other.
I prefer to stick the drill into the vent and drill up into the attic instead of drilling down from the attic.
Imo cutting a hole in the sheet rock on the wall and lid and drilling your holes up into the top plate would be the easiest solution.
Cutting drywall and drilling from below may be the only option if you have to access the attic there.
Just don t drop the drill.
I ve got a 2nd story home theater room under construction.
An alternative is to drop all the way through the wall cavity from another top plate in the attic and into the basement or crawlspace then run over to the wall you want to end up in.
If this is just a partition wall not load bearing and the wall is well supported on both sides of where you want to drill the holes i don t think there is any limit.
The framing has been done but i m going to be doing the wiring myself.
This will also make it easier to fish the wire.
To fix it you just fill the gap with caulk or spray foam.