There are two primary references that have been used throughout the country in relation to accessibility: ICC/ANSI A117.1, Accessible and Usable Buildings and Facilities and The Americans With Disabilities Act Accessibility Guidelines (ADAAG).
ANSI A117.1 Accessible and Usable Buildings and Facilities.
Originally created and published by the Council of American Building Officials (CABO) – ANSI A117.1 is now overseen by the ICC.
First published in 1986 – predating the ADA – this was considered the standard for use in designing an accessible facility. However, the 1986 publication noted an incorrect dimension for handrail. Handrail was required to be between 1 1/4″ and 1 1/2″ outside diameter with a clearance between the wall and handrail of 1 1/2″.
Problem – these were tube sizes. The railing industry typically uses nominal pipe of 1 1/4″ and 1 1/2″ (actual diameter of 1.66″ and 1.90″, respectively) in railing as it is thicker and stronger than tube. CABO acknowledged their error as the dimensions were meant to apply to a grab bar. A correction was made and when reprinted in 1990, the handrail size was updated to allow for a diameter of between 1 1/4″ and 2″.
Americans With Disabilities Act (ADA)
The ADA became law in July 1990. It requires that all new places of public accommodation and commercial facilities be designed and constructed so as to be readily accessible and usable by persons with disabilities. It is overseen by the United States Access Board.
The ADA is Civil Rights Law – it prohibits discrimination on the basis of disability. Violation could subject a facility owner to a civil suit for discrimination. The ADA applies to facilities in the private sector – places of public accommodation and commercial facilities – and to state and local government facilities. The standards are issued by the Department of Justice (DOJ)
In 1991, the Americans With Disabilities Act Accessibility Guidelines (ADAAG) were prepared by The Access Board and added as an appendix to the ADA.
The Access Board did not create their own standard. They instead relied on the standards that made up ANSI A117.1. However, though ADAAG was published in 1991 – a year after the updated A117.1 – it used the 1986 standard and carried over the incorrect handrail dimensions making them federal law.
When contacted, the Access Board acknowledged the error as well but did not publish a clarification until July 1998 which allowed for 1 1/4″ and 1 1/2″ nominal pipe sizes (1.66″ and 1.90″ diameter – respectively). The Access Board announced the release of a new ADAAG in 2004. However, it was not approved by the Justice Department until July 23, 2010. The new ADA Standards for Accessible Design (ADASAD) went into effect on March 15, 2011 but was not required until March 15, 2012.
As with building codes, it is wise to confirm with your local jurisdiction as some have stricter requirements. Some states have their own accessibility standards. California, most notably, still has a requirement that handrail must have an absolute clearance between the wall and handrail of 1 1/2″ (ADA notes this requirement as 1 1/2″ minimum).
The ABA is similar to the ADA and also uses the ADASAD. The ABA applies to federally funded facilities – e.g., US Postal Services (USPS), Department of Defense (DOD), and Department of Housing and Urban Development (HUD). It is interesting to note that while the ADA was not approved until 2010, the ABA was approved in 2005 – shortly after the completion of the ADA review process in 2004.