T-Shaped Turn using clearance under a counter

[Michael.L]

I am planning the floor layout for our small shop. The service counter has a section of limited space in front due to the presence of an HVAC return air plenum for the shopping mall common area; this plenum protrudes into our leased space, rising 25" up from the floor. To comply with accessibility requirements, I plan to create a T-shaped turning space where the base of the T extends into a clear space under the counter. I intend to allow 37" (36" required + 1" extra) of floor space between the face of the plenum and the service counter. The clear space under my counter is at least 27-3/4" continuous from the front to the back. Refer to the following illustration:

However, an architect advised me that the base of the T can only extend 17" (6" toe + 11" knee) under the counter, and thus I must allow a minimum of 43" between the plenum and the counter. He sent me this diagram, taken from some code reference (I have yet to hear back from him on the source), to illustrate:



But my reading of the ADA code requirements does not agree with the interpretation depicted in the diagram. As I read it, the 6" of toe space and 11" of knee space are listed in the ADA Standards as minimums, not maximums. I'll quoting below the relevant sections extracted from the DOJ's "2010 ADA Standards for Accessible Design" with the applicable requirements highlighted. My comments follow the quoted material.

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304 Turning Space

304.1 General. Turning space shall comply with 304.

304.3 Size. Turning space shall comply with 304.3.1 or 304.3.2.

304.3.2 T-Shaped Space. The turning space shall be a T-shaped space within a 60 inch (1525 mm) square minimum with arms and base 36 inches (915 mm) wide minimum. Each arm of the T shall be clear of obstructions 12 inches (305 mm) minimum in each direction and the base shall be clear of obstructions 24 inches (610 mm) minimum. The space shall be permitted to include knee and toe clearance complying with 306 only at the end of either the base or one arm.

Figure 304.3.2 T-Shaped Turning Space​

305.4 Knee and Toe Clearance. Unless otherwise specified, clear floor or ground space shall be permitted to include knee and toe clearance complying with 306.

306 Knee and Toe Clearance

306.1 General. Where space beneath an element is included as part of clear floor or ground space or turning space, the space shall comply with 306. Additional space shall not be prohibited beneath an element but shall not be considered as part of the clear floor or ground space or turning space.

306.2 Toe Clearance.

306.2.1 General. Space under an element between the finish floor or ground and 9 inches (230 mm) above the finish floor or ground shall be considered toe clearance and shall comply with 306.2.

306.2.2 Maximum Depth. Toe clearance shall extend 25 inches (635 mm) maximum under an element.

306.2.3 Minimum Required Depth. Where toe clearance is required at an element as part of a clear floor space, the toe clearance shall extend 17 inches (430 mm) minimum under the element.

306.2.4 Additional Clearance. Space extending greater than 6 inches (150 mm) beyond the available knee clearance at 9 inches (230 mm) above the finish floor or ground shall not be considered toe clearance.

306.2.5 Width. Toe clearance shall be 30 inches (760 mm) wide minimum.

Figure 306.2 Toe Clearance​

306.3 Knee Clearance.

306.3.1 General. Space under an element between 9 inches (230 mm) and 27 inches (685 mm) above the finish floor or ground shall be considered knee clearance and shall comply with 306.3.

306.3.2 Maximum Depth. Knee clearance shall extend 25 inches (635 mm) maximum under an element at 9 inches (230 mm) above the finish floor or ground.

306.3.3 Minimum Required Depth. Where knee clearance is required under an element as part of a clear floor space, the knee clearance shall be 11 inches (280 mm) deep minimum at 9 inches (230 mm) above the finish floor or ground, and 8 inches (205 mm) deep minimum at 27 inches (685 mm) above the finish floor or ground.

306.3.4 Clearance Reduction. Between 9 inches (230 mm) and 27 inches (685 mm) above the finish floor or ground, the knee clearance shall be permitted to reduce at a rate of 1 inch (25 mm) in depth for each 6 inches (150 mm) in height.

306.3.5 Width. Knee clearance shall be 30 inches (760 mm) wide minimum.

Figure 306.3 Knee Clearance​

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My comments:

Note that the 11" of knee space under the counter in the diagram provided by the architect appears to come from section 306.3.3. But that is a minimum dimension (to ensure the knees can fit fully under the counter). The only maximum depth dimensions I can find are 25" for toe clearance (306.2.2) and 25" for knee clearance (306.3.2). It's my understanding that these maximums are intended to prevent the person in the wheelchair from being too far away from whatever he/she may be trying to reach above the obstruction. In any case, the base of the T-shaped turning space is 24" so it should fit entirely within the 25" maximum depth requirements.

I'd appreciate feedback on this as I want to make sure my interpretation of the code is not in error.

 

[RLGA]

17 inches is the minimum and 25 inches is the maximum. What you've shown should be acceptable.

 

[classicT]

I agree with Ron, you are on the right track.

 

[ADAguy]

And you "need" to go through this analysis why? Space available limited?

That plenum will really get beat up, you leave no "oops" room at all. Especially by electric WC's.

May meet minimums but not a best practice.

 

[JPohling]

I agree that what you are proposing is code minimum and per your analysis is "compliant". I would make sure the building official in your jurisdiction agrees with your interpretation. That is who you will need to satisfy.

 

[Michael.L]

And you "need" to go through this analysis why? Space available limited?

That plenum will really get beat up, you leave no "oops" room at all. Especially by electric WC's.

May meet minimums but not a best practice.

Trust me, we wouldn't be jumping through these hoops if we didn't "need" to. The space available is VERY limited. We tried to lease a space that was over twice the size, but a larger tenant (who was combining that space with an adjacent one) got it. This small space was all that remained and, while we were grateful to get it, it has proven to be challenging and requires compromises on our original concept.

This space is very narrow and has an offset jog in the wall (not pictured in my diagram for simplicity) which forces us to place the service counter behind that plenum. And moving the counter farther back from the plenum will have a domino effect on all the other fixtures and work areas inside the shop. Getting everything to fit has been quite a challenge so I really do not have extra inches to work with, especially for code requirements that will likely get minimal usage. Our shop is in a fairly small city and I've yet to see a single wheelchair user in the mall where we are locating our shop. Of course, that could change during our five-year lease. But given our circumstances, meeting ADA minimums are the best practice. If that means having to cosmetically touch-up the plenum from time-to-time, so be it.

 

[Michael.L]

I would make sure the building official in your jurisdiction agrees with your interpretation. That is who you will need to satisfy.

I absolutely agree. It's unfortunate that the DOJ's Accessibility Standards document does not make more of these scenarios clear so there is less confusion and not be subject to varying interpretations at the local level.

I politely reached out to our city's commercial building official requesting a preliminary meeting to discuss this and a couple of other concerns. But he turned me down, saying that his department is too small to schedule meetings in advance of TI plans submittal.

 

[ADAguy]

You mention a mall location, is the RR for employees only?

 

[Michael.L]

You mention a mall location, is the RR for employees only?

I'm not sure what RR refers to. But this is for a retail establishment, open to the general public.

 

[ADAguy]

RR: restroom,
you indicate it is to be for public use; being in Colorado you may be less likely to have to deal with drive-by access suits.

 

[Michael.L]

RR: restroom,
you indicate it is to be for public use; being in Colorado you may be less likely to have to deal with drive-by access suits.

Thanks for the clarification. Sorry, I was thinking just about the service counter so I couldn't imagine what RR meant.

Last year I had a lot of questions about building an ADA restroom because we were looking at a different shop location that did not have restroom access. But we ultimately rejected that location. The space we have recently leased is part of a shopping mall and has public restrooms in the mall common area so (thankfully!!) we don't have to deal with that at all. There is also an employee-only restroom off the service corridor behind our space; our back door opens into that service corridor.

Having lived in California up until a year ago, I'm well-aware of the cottage industry of "drive-by" ADA compliance lawsuits. I haven't heard of that here in Colorado yet, but I don't want to take any chances. It's one of the reasons I've been doing so much ADA research up-front.