If you are trying to modify an apartment lot when it is not in use (from neighborhood, no one living in it), it is much easier to revert the lot back to residential only (ChangeLotZoning residential), make your modifications, then make it to apartment again (changeLotZoning apartmentbase). You know that everything is alright when you get the different mailbox.
To correct apartments using cheats will have one drawback - when you move the sims out and move in again the apartment will revert to the previous condition (before your modifications). Anyway I do not play apartments much but I noticed that you have constantly to move sims from their apartments once apartments have a tendence to accumulate errors with the playing time. Maybe this was the reason it was defined the way it is.
To say the truth Apartment Life is 100% dependent on a mod from Pescado (FFS debugger). If you do not have it, go there and download it. It seems that EA works for Pescado.
