Where I am, no permitting is required, and no inspection will take place, for anything done inside a residence.  Yes, you can gut a condo and place $500K worth of new work inside, and not need the permit, nor submit plans, nor ever see an inspector. 

But that doesn’t mean we can ignore codes.

I looked at some kitchen work today in a condo, the purpose being to see what was done to a neighboring unit, one in which the owner of the one I am refiguring, sees a lot of ideas he would like to incorporate in a remodel.

These units are middle flats, with neighbors under the floors, and above the ceilings.  One wall of the condos, both identical in plan, will have a run of the kitchen work against it, and the walls are party walls, meaning common with the neighboring unit.

In the very-well-done kitchen I saw today, it looked as if both walls and ceilings were boosted in and down respectively, in order to do things like can lights, new electrical runs, and vent piping.

My guess is that there are two layers of 5/8 firecode gyprock on these walls and ceilings, and that code would say they cannot be penetrated.

What say you?