Table 6.18 – Accessible Routes in Dwelling Units with Mobility Features
Current Guidelines:  
4.34.1  General.  The requirements of 4.34 apply to dwelling units required to be accessible by 4.1.

4.34.2  Minimum Requirements.  An accessible dwelling unit shall be on an accessible route.  An accessible dwelling unit shall have the following accessible elements and spaces as a minimum: . . .

(3)  At least one accessible route complying with 4.3 shall connect the accessible entrances with all accessible spaces and elements within the dwelling units. . . .

(12)  At least one full bathroom shall comply with 4.34.5. . . .

(13)  The kitchen shall comply with 4.34.6.

(14)  If laundry facilities are provided, they shall comply with 4.34.7.

(15)  The following spaces shall be accessible and shall be on an accessible route:  

(a)  The living area.

(b)  The dining area.

(c)  The sleeping area, or the bedroom in one bedroom dwelling areas, or at least two bedrooms or sleeping spaces in dwelling units with two or more bedrooms.

Final Revised Guidelines:  
233.3.5 Dispersion.  Residential dwelling units required to provide mobility features complying with 809.2 through 809.4 . . . shall be dispersed among the various types of residential dwelling units in the facility and shall provide choices of residential dwelling units comparable to, and integrated with, those available to other residents.
Exception:  Where multi-story residential dwelling units are one of the types of residential dwelling units provided, one-story residential dwelling units shall be permitted as a substitute for multi-story residential dwelling units where equivalent spaces and amenities are provided in the one-story residential dwelling unit.

809.1 General. . . . Residential dwelling units required to provide mobility features shall comply with 809.2 through 809.4 . . . .

809.2 Accessible Routes.  Accessible routes complying with Chapter 4 shall be provided within residential dwelling units in accordance with 809.2.
Exception:  Accessible routes shall not be required to or within unfinished attics or unfinished basements.
 
809.2.1 Location.  At least one accessible route shall connect all spaces and elements which are a part of the residential dwelling unit.  Where only one accessible route is provided, it shall not pass through bathrooms, closets, or similar spaces.  

809.4 Toilet Facilities and Bathing Facilities.  At least one toilet facility and bathing facility shall comply with 603 through 610.  At least one of each type of fixture provided shall comply with applicable requirements of 603 through 610.  Toilet and bathing fixtures required to comply with 603 through 610 shall be located in the same toilet and bathing area, such that travel between fixtures does not require travel between other parts of the residential dwelling unit.

Model Codes & Standards
ICC/ANSI A117.1-1998:  Section 1002.3 has an equivalent requirement for accessible routes in Type A dwelling units.