ANSI A117 – Everything Old is New Again: Codes

Erick Mikiten, AIA, LEED-AP

Change is on the horizon for accessibility requirements.

The ADA and the CBC (California Building Code) are both based on 1970’s studies that determined things like turning radius, clear space, and reach. It was good work, but the sample sizes were small, and some mobility devices—like scooters—didn’t exist.

This column previously explored the history of the1959 standard “ICC/ANSI A117.1 Accessible and Usable Buildings and Facilities.” The authors of that first version of A117 had impressive foresight in thinking about what people with disabilities needed to navigate the built environment.

A few years ago the US Access Board (the federal agency that issues the ADA) sponsored a new research project to collect data on 500 people with disabilities, mainly focusing on wheeled mobility devices. It was done by the IDeA Center (Center for Inclusive Design and Environmental Access) at the University of Buffalo. For this article, I contacted the center’s director, Edward Steinfeld, AIA, Arch.D and Jonathan White, who worked on the new study. That study informed the new 2017 version of ANSI A117, which – over time – will precipitate changes to the ADA guidelines and the CBC.

The new standards make many adjustments to maneuvering spaces, reach ranges, and other clearances that are more realistic today. Some seem broad and others dramatic, but it’s notable that in many areas, Australian and UK code have space requirements that are larger than in the new A117.

The Changes

A117 updated and added interesting technical requirements such as classroom acoustics, sign language interpreter stations and video relay service booths. But I’ll focus here on a few spatial changes.

Clear Space

A117 makes a fundamental change to the length of a wheelchair clear space. This grew from 48 inches to 52 inches. Those four inches don’t sound like much, but the effect ripples through other requirements, such as restroom stalls, auditorium seating, platform lifts, etc.

The larger clear space increases the required turning space from 60 to 67 inches. This odd number is a little awkward to work with, but is an example of the push and pull that happens in the public negotiation process.

We have a lot of existing buildings that don’t meet this and many  of the other new standards, so A117 splits many requirements into two categories: New Buildings and Existing Buildings.

In the example of turning space, a wheelchair was previously allowed to turn underneath a countertop, sink, or other obstruction that provided knee and toe clearance. That overlap was limited to the 25 inches of toe clearance defined elsewhere.

Now A117 has two standards: for existing buildings we retain the 60-inch circle and 25-inch maximum overlap with knee and toe space. But new buildings have the 67-inch circle with a maximum overlap of ten inches. This is an improvement for access. Even with a compact manual wheelchair, I’ve encountered many restrooms where I’m barely threading myself through these overlapping clearances that would be impossible with an electric chair or a scooter. This change will enlarge restrooms, changing rooms, and many other spaces, giving people with larger devices a chance for equal use.These are just a few examples of the many changes in A117. Other big ones are 90-degree and 180-degree turns in accessible routes, changes to the T-shaped turning space and new clear space requirements for front-approach doors.


Here’s an interesting diagram from the IDeA Center’s anthropometric study. It shows reach ranges for people in manual wheelchairs, with numbers on a grid indicating the percentage of people able to reach certain distances. Similar analyses were done for people in electric wheelchairs and people using scooters.

This graphic shows that for the standard 48-inch-high element, 99 percent of people can reach it if it’s close to their torso, but that percentages drops quickly down to 69 percent if it’s at the same height above their toes. For scooter users, it’s only 46 percent.

Even with this new data, the committee did not make any changes to reach standards in the new A117, but you can use the information to inform your own work and we should all expect changes in the next update.

The Future

Changes to the ADA are slow, and with Washington in a quagmire, don’t expect any of the A117 requirements to show up in the ADA soon.

Changes to the CBC are also slow. But since it’s based on the IBC, and the IBC creators (ICC – the International Code Council) may incorporate the new A117 sooner, my guess is that it will trickle down from ICC to CBC before we see it in the ADA.

So what’s an architect to do now? Get a copy of the new standard, and use the design principles to make your architecture better serve your community. Architects are innovators, not followers, and if we can get some experience with these new standards in the next few years, we will be in a position to influence changes to Title 24. Not only will you be doing a great service to people with disabilities, but you can tell your clients that you’re looking ahead, and doing what you can to help them future-proof their building, both for their legal protection and in service of our aging population.

I will be interested to see what you design! And as the Accessibility Representative on California’s Building Standards Commission, I’ll be eager to share your experiences in Sacramento.

Comments from Kerwin Lee, AIA, CASp:

It needs to be understood that the authors of the A-117.1 Standards are part of the ICC code process. ICC is a private organization not directly tied to the Government. Supposedly, it is an open public process and anyone can write a code change. These new standard are controversial and were debated at great lengths in committee and at the open ICC code development hearings. It did not make it into the 2016 edition of the IBC and some say that it may or may not make it into a future edition. Because it is not codified in the American with Disabilities Act (ADA) Standards, it is not required for compliance with the ADA, at least at this time.

Remember that California does not adopt or use ANSI A-117.1 as a standard for their building code; we have our own Chapter 11B, which is unique and different from the IBC, which does reference the A-117.1 Standard. California is just beginning their code development cycle for the next edition of the codes. It will be interesting to see what of the new standards makes its way into the CBC and in what form. The biggest issue I see is the proposed separation of “New” and “Existing” buildings. The application and use of the “Path of Travel” requirements in the CBC will need to be addressed in detail on how this works. There are many questions that need to be addressed if any of these are added to the CBC.


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