Table 7.10.1 – Water Closet Clearance in Toilet Rooms
Current Guidelines:  
4.16.2  Clear Floor Space.  Clear floor space for water closets not in stalls shall comply with Fig. 28. . . .

[Note:  Figure 28 shows three configurations for the clearance around a water closet depending on the type of approach:

(a) Where only a forward approach to the water closet is provided, the clearance is 48 inches minimum measured perpendicular from the side wall and 66 inches minimum measured perpendicular from the rear wall.  A lavatory with knee and toe clearance and 18 inches minimum from the water closet centerline is permitted on the wall behind the water closet. 

(b)  Where only a parallel approach to the water closet is provided, the clearance is 48 inches minimum measured perpendicular from the side wall and 56 inches minimum measured perpendicular from the rear wall.  A lavatory with knee and toe clearance and 18 inches minimum from the water closet centerline is permitted on the wall behind the water closet.

(c)  Where both a forward approach and a parallel approach to the water closet are provided, the clearance is 60 inches minimum measured perpendicular from the side wall and 56 inches minimum measured perpendicular from the rear wall.  No other fixture is permitted to overlap the water closet clearance.]

Final Revised Guidelines:  
604.3  Clearance.  Clearances around water closets and in toilet compartments shall comply with 604.3.

604.3.1  Size.  Clearance around a water closet shall be 60 inches (1525 mm) minimum measured perpendicular from the side wall and 56 inches (1420 mm) minimum measured perpendicular from the rear wall.

604.3.2  Overlap.  The required clearance around the water closet shall be permitted to overlap the water closet, associated grab bars, dispensers, sanitary napkin disposal units, coat hooks, shelves, accessible routes, clear floor space and clearances required at other fixtures, and the turning space.  No other fixtures or obstructions shall be located within the required water closet clearance.
Exception:  In residential dwelling units, a lavatory complying with 606 shall be permitted on the rear wall 18 inches (455 mm) minimum from the water closet centerline where the clearance at the water closet is 66 inches (1675 mm) minimum measured perpendicular from the rear wall.

Model Codes & Standards
ICC/ANSI A117.1-1998:  Section 604.3 has an equivalent requirement for water closet clearance in toilet rooms.  Section 1002.5.2 specifies three configurations for the clearance around a water closet in toilet rooms in Type A dwelling units depending on the type of approach.