You've gotta install <b>three</b> dedicated circuits, strictly from the standpoint of the way these outlets are used today:
Most hair dryers today are roughly 1850W or so. So if three people are drying their hair, that's 46.24A which mean trip. If two people are drying their hair, that's 30.83A which also means trip. With three seperate 20A runs, everyone can dry their hair in harmony.
I say to heck with the plans, you're the electrician and the one they'll blame when the circuits don't work as expected. So tell them it will be necessary for you to deviate from plans, and additional charges will result. Any HO or GC will understand, and probably appreciate you're "correcting" the architects "error" so to speak. A good architect (without an easily bruised ego) will even appreciate this.
I say better to address the likely problem now, than having to fish later on. Changes often have to be made from plans. Besides, how would it look if you just kept your mouth shut, and then the HO or GC blasts you for not being "competent" for just following plans blidnly.
Joe
