Effective March 15, 2012, the applicable standards for new construction and alterations for either a public entity under Title II or a place of public accommodation under Title III are the 2010 ADA Standards for Accessible Design. The 2010 ADA Standards can be found at: http://www.ada.gov/2010ADAstandards_index.htm [2].
For additional information, take a look at the following resources:
FAQ: Where can I find a complete set of ADA standards for accessible design? [3]