dave wrote:

Building more capacity than is required is a waste of resources. Same
mentality as driving a vehicle with bad mileage for no compelling
reason. There is so little conservation in most houses. With
fluoresant lighting, 10 amp breakers would be overkill. When people
start paying 25 cents and up a KWH maybe there will be some forced
common sense.

Not at all. It is all a matter of your time horizon. Most houses will
last at least 100 years if properly maintained. The electrical wiring
will likely last at least 50 years before needing replacement. You have
no way to know what the load requirements will be in 10 years, let alone
50 years. Kitchens built 50 years ago had plenty of ampacity for the
needs then, but their wiring is now woefully inadequate for a modern
suite of appliances. It is almost certain that electrical needs will
increase rather than decrease, even with more efficient appliances and
lighting. Providing more than just the bare minimum capacity for
today's needs is not at all wasteful as it costs a lot more resources to
retrofit later. And, as another poster already pointed out, the lower
IsquaredR loss in the heavier wire actually saves energy and money over
the long haul.


Matt