and with all the varied turns and curves a run of romex takes in wending its way though a structure.. are you supposed to cut it @ 75 feet and just see where the wire runs out? I am still of two minds on this one.. yes houses have worked well for 100 years, but uses for electricity (as well as electricity usage) in homes has also changed in that time. Might be overkill, but why not build them to the best standards that the times allow? At the turn of the century a single 20A circuit was deemed adequate to supply an entire household, back in the days when consumer appliances consisted of: 1.incandescent lights, 2. incandescent lights, 3. incandescent.. there were no plasma tv's, kitchenaid mixers, conair blowdryers, garbage disposals or garage arcwelders (there weren't even cars to park inside.. garages were for horse carriages..) I think it is a lot cheaper to build in the capacity before the drywall goes on. Whatever it costs it is still cheaper than adding it years after or even hours after the drywall goes up.
As an aside, I am wondering if in 100 years our present power usage in homes won't be looked upon as just as quaint, not for how little we built into the building but for how much we built in. With more efficient and lower power consuming products coming out every day, as well as all the essentially DC stuff like computers & PV Cells.. who knows, maybe they will say in 100 more years that Edison was right with his DC power (!?!?!)
But to get back to the original point.. I don't think you can ever go wrong building it good and building it right, and keeping voltage drop under control is part of "building it right". What has me scratching my head a little is how this will be enforced by inspectors- seems a bit time consuming and opens a can of worms for determining what work on whose side of the line is at fault..I mean how does one accurately measure the lenght of a run once it is on the frame of the house? And if the VD is over the limit, you could also argue it a few ways to keep the issue going round-and-round, to no resolution. Sounds like a good idea on paper and also a goal worth striving for as the electrician, but I also see lots of gray area.
