"406.3.1 Water closets, lavatories and bidets. A water closet, lavatory or bidet shall not be set closer than 15 inches from its center to any side wall, partition, vanity or other obstruction, or closer than 30 inches center-to-center between toilets or adjacent fixtures. There shall be at least 18 inches clearance in front of the water closet or bidet to any wall, fixture or door. Water closet compartments shall not be less than 30 inches wide and 60 inches deep. There shall be at least 18 inches clearance in front of the lavatory to any wall, fixture or door."
1995 IPC Fixture Clearances