we just did a large home. the drawing said half of the receptacles per room, half of the lights per room were to be on the genset. This required twice the work, twice the labor and twice the switchgear. we upped the 80kv to a 120kw and did the whole house. was cheaper in the long run and completely eliminated, "Oh can we now have that too on the genset?"
Diplomacy is the art of saying hire a pro without actually saying hire a pro