There are two types of accessible guest rooms, one type having “mobility features” and the other “communication features.” The minimum number of accessible guest rooms in newly constructed facilities is provided in Tables 224.2 (mobility features) and 224.4 (communication features) of the 2010 ADA Standards for Accessible Design - http://www.ada.gov/2010ADAstandards_index.htm. Note that for rooms with mobility features, roll-in showers will be required where the total number of guest rooms provided exceeds 50.
In alterations and additions, the minimum required number of accessible guest rooms required is based on the total number of guest rooms being altered or added instead of the total number of guest rooms provided in a facility. Note, that where guest rooms are altered, or added, the technical requirements stated in the 2010 ADA Standards apply only to those guest rooms being altered or added until the total number of accessible guest rooms in the entire hotel complies with the minimum number required for new construction as stated in the tables referred to above.
Accessible guest rooms must be dispersed among the various classes of guest rooms, and provide choices of types of guest rooms, number of beds, and other amenities comparable to the choices provided to other guests. Typically, each alteration of a facility is limited to a particular portion of the facility. As accessible guest rooms are added as a result of subsequent alterations, the required degree of dispersion is more likely to be achieved if all of the accessible guest rooms are not provided in the same portion of the facility.
Source: Section 224.1.1, and accompanying Advisory, of the 2010 ADA Standards for Accessible Design - http://www.ada.gov/2010ADAstandards_index.htm.
For additional information, take a look at the following resources:
FAQ: What are public accommodations?
Fact Sheet: Accessible Lodging