ADAS / 11B 104.1.1 construction tolerance

[Yikes]

A CASp recently reminded be that both ADA and CBC 11B 104.1.1state: "All dimensions are subject to conventional industry tolerances EXCEPT where the requirement is STATED as a RANGE with specific MINIMUM AND MAXIMUM end points. "
So tolerances ARE allowed when there is no stated range with specific minimum AND maximum end points. Note the importance of the word "stated".

For example, 804.2.2 states that U-shaped kitchens need a minimum of 60 inches between opposing cabinets, countertops, appliances or walls. If the plans state minimum 60" but it gets built at something less than 60", that may still be acceptable under ADA and 11B, assuming the difference is within "conventional industry tolerances".

Neither ADA nor 11B attempt to definitively answer the question: whose tolerances represent "conventional industry tolerances"? Is it a construction trade association? Is it a widely recognized book published by an individual author, such as David Kent Ballast's "Handbook Of Construction Tolerances"?
It gets even more complicated in this kitchen example. Say the space between a refrigerator and the tile countertop on a cabinet on the opposite wall is 59.5". What tolerance do you reference? Did the rough framer build the wall within industry standard framing tolerances for framing? Did the tile installer follow Tile Council of North America tolerances? The refrigerator manufacturer might say they need min. 1" clearance to the back coils, but did the refrigerator installer put the fridge too far away from the wall? What about the device used to measure the finished clearance - - what is its tolerance? And are all the tolerances cumulative amongst all trades' own tolerances?

The CASp I talked to believes that in that example it is ultimately up to the design professional of record to determine what is considered acceptable tolerances. Of course, in the example above, any installed dimension that is less than the 60" min. is begging for litigation, and even if the DPOR ultimately prevails in court, was it worth the hassle?
Thant's why the USDOJ has issued an advisory stating that:
(1) DPORs should avoid stating a construction tolerance on plan that is noncompliant with the stated minimum or maximum.
(2) DPOR should consider baking in the tolerance on the stated dimension:

Example, if the DPOR has somehow determined that 1/4" construction tolerance at the kitchen width is a "conventional industry tolerance":

• ACCEPTABLE PRACTICE is to state on the plans: minimum 60" clear
• NOT GOOD PRACTICE is to state on the plans: minimum 60" clear +/- 1/4" construction tolerance
• GOOD PRACTICE is to state: minimum 60 1/4" clear.

IMO, BEST practice would be to add some tolerance to the tolerance, for example: "min. 61" clear".

Lastly, in 104.1.1 notice the importance of the word "stated" in describing both the minimum and maximum end points. Implied zero or infinity does not count as a stated range. If a regulation says "maximum 5 lbs. force" but does not state it as "0 - 5 lbs. force", then it is not a "stated range" and therefore conventional industry tolerances are allowed to apply to the max. 5 lbs. force.

*******************************************************


Excerpt from DOJ advisory:

Conventional industry tolerances recognized by this provision include those for field conditions and those that may be a necessary consequence of a particular manufacturing process. Recognized tolerances are not intended to apply to design work.

It is good practice when specifying dimensions to avoid specifying a tolerance where dimensions are absolute. For example, if this document requires “1 inches,” avoid specifying “1 inches plus or minus X inches.”

Where the requirement states a specified range, such as in Section 609.4 where grab bars must be installed between 33 inches and 36 inches above the floor, the range provides an adequate tolerance and therefore no tolerance outside of the range at either end point is permitted.

Where a requirement is a minimum or a maximum dimension that does not have two specific minimum and maximum end points, tolerances may apply. Where an element is to be installed at the minimum or maximum permitted dimension, such as “15 inches minimum” or “5 pounds maximum”, it would not be good practice to specify “5 pounds (plus X pounds) or 15 inches (minus X inches).” Rather, it would be good practice to specify a dimension less than the required maximum (or more than the required minimum) by the amount of the expected field or manufacturing tolerance and not to state any tolerance in conjunction with the specified dimension.

Specifying dimensions in design in the manner described above will better ensure that facilities and elements accomplish the level of accessibility intended by these requirements. It will also more often produce an end result of strict and literal compliance with the stated requirements and eliminate enforcement difficulties and issues that might otherwise arise. Information on specific tolerances may be available from industry or trade organizations, code groups and building officials, and published references.

 

[Joe.B]

U.S. Access Board - Final Report

The U.S. Access Board is a federal agency that promotes equality for people with disabilities through leadership in accessible design and the development of accessibility guidelines and standards for the built environment, transportation, communication, medical diagnostic equipment, and...

www.access-board.gov

 

[arwat23]

A CASp recently reminded be that both ADA and CBC 11B 104.1.1state: "All dimensions are subject to conventional industry tolerances EXCEPT where the requirement is STATED as a RANGE with specific MINIMUM AND MAXIMUM end points. "
So tolerances ARE allowed when there is no stated range with specific minimum AND maximum end points. Note the importance of the word "stated".
...
Lastly, in 104.1.1 notice the importance of the word "stated" in describing both the minimum and maximum end points. Implied zero or infinity does not count as a stated range. If a regulation says "maximum 5 lbs. force" but does not state it as "0 - 5 lbs. force", then it is not a "stated range" and therefore conventional industry tolerances are allowed to apply to the max. 5 lbs. force.

I disagree. A minimum OR maximum OR minimum and maximum (range) remove allowances for tolerances, not just having a minimum and maximum.

For example, a mirror in a bathroom is required to comply with 11B-603.3. That section has a stated maximum height to the bottom of the reflecting surface, but there's no minimum specified. A mirror can be installed as low as you want, but cannot exceed the specified maximum.

A "maximum 5 lbs of force" states a maximum, a "not to exceed". You cannot go above 5 lbs if that's the "maximum" allowed.



If there's no "minimum" or "maximum" or range specified, then yes, construction tolerances can apply.

Edit: A kitchen with a code-required 60" minimum width cannot be less than 60" wide. It can be more than 60", but cannot be less.

 

[Yikes]

I disagree to an extent. A minimum OR maximum OR minimum and maximum (range) remove allowances for tolerances, not just having a minimum and maximum.

For example, a mirror in a bathroom is required to comply with 11B-603.3. That section has a stated maximum height to the bottom of the reflecting surface, but there's no minimum specified. A mirror can be installed as low as you want, but cannot exceed the specified maximum.

A "maximum 5 lbs of force" states a maximum, a "not to exceed". You cannot go above 5 lbs if that's the maximum allowed.

View attachment 16691

In 104.1 note the phrase "for design purposes". I totally agree that my plans cannot state a design higher than 5 lbs.
But 104.1.1 and this thread is not about design tolerances. It is about construction and manufacturing tolerances.


The DOJ advisory quoted in post #1 says: "Where a requirement is a minimum or a maximum dimension that does not have two specific minimum and maximum end points, tolerances may apply."
https://www.ada.gov/law-and-regs/design-standards/2010-stds/#104-conventions#section23

 

[arwat23]

In 104.1 note the phrase "for design purposes". I totally agree that my plans cannot state a design higher than 5 lbs.
But 104.1.1 and this thread is not about design tolerances. It is about construction and manufacturing tolerances.

View attachment 16692
The DOJ advisory quoted in post #1 says: "Where a requirement is a minimum or a maximum dimension that does not have two specific minimum and maximum end points, tolerances may apply."
https://www.ada.gov/law-and-regs/design-standards/2010-stds/#104-conventions#section23

Pretty sure DSA has mentioned in their CASp Code Discussion Groups that a maximum or minimum is considered a hard limit when it comes to CASp inspections, which would mean it applies to construction and manufacturing tolerances since that's what I'm inspecting. Or I'm misremembering... Always a possibility.



The way I'm reading this advisory, the maximum or minimums are meant to be taken as absolute limits of construction and manufacturing, at least for 11B. Why else would they advise us to specify something lower than the maximum or higher than the minimum on design documents? If maximum or minimums aren't hard limits, why advise this?

 

[Yikes]

Pretty sure DSA has stated that a maximum or minimum is considered a hard limit when it comes to CASp inspections (which would mean it applies to construction and manufacturing tolerances if that's what I'm inspecting), at least in their CASp Code Discussion Groups. Or I'm misremembering... Always a possibility.

View attachment 16699

The way I'm reading this advisory, the maximum or minimums are meant to be taken as absolute limits of construction and manufacturing. Why else would they advise us to specify something lower than the maximum or higher than the minimum on design documents? If those aren't hard limits, why advise this?

Ignoring that, why would code specify a "maximum" if that's not truly a "maximum"? Why not just say something like "a mirror shall be 40" a.f.f."? No max or min, and allows for construction tolerances per 104.1.1.

Going with your mirror example, which has a stated maximum for reflective surface at 40" AFF, and has no stated minimum:
For design purposes, what is shown in the construction documents cannot exceed 40". The plans cannot say "maximum 40.01". That would not comply with the DSA advisory above. But note the recurring phrases in the advisory such as "for design work" and "dimensions for design".

The discussion of tolerances in the DSA advisory in 104.1.1 is not intended for design, but it IS intended for construction and manufacturing.
So if the design (plans) say max. 40", and the as-constructed dimension is 40.01", then ADA / 11B-104.1.1 says that may be within conventional building industry tolerances and therefore allowable under ADA and 11B.

That doesn't mean that some enterprising litigant won't challenge it in court. But if it lands in court, then 104.1.1 provides the mechanism and context under which it may ultimately be deemed by the court to be in compliance with ADAS and/or 11B, even with an installed condition of 40.01" while the plans still say maximum 40".

OF course if you are the DPOR, you likely have the contractual right to reject a mirror at 40.01", even if the courts say it complies with the tolerances described in ADA.

 

[Yankee Chronicler]

Pretty sure DSA has mentioned in their CASp Code Discussion Groups that a maximum or minimum is considered a hard limit when it comes to CASp inspections, which would mean it applies to construction and manufacturing tolerances since that's what I'm inspecting. Or I'm misremembering... Always a possibility.

View attachment 16699

The way I'm reading this advisory, the maximum or minimums are meant to be taken as absolute limits of construction and manufacturing, at least for 11B. Why else would they advise us to specify something lower than the maximum or higher than the minimum on design documents? If maximum or minimums aren't hard limits, why advise this?

This is the way I have always understood it. Minimum means minimum, not minimum plus-or-minus x.

 

[arwat23]

Going with your mirror example, which has a stated maximum for reflective surface at 40" AFF, and has no stated minimum:
For design purposes, what is shown in the construction documents cannot exceed 40". The plans cannot say "maximum 40.01". That would not comply with the DSA advisory above. But note the recurring phrases in the advisory such as "for design work" and "dimensions for design".

The discussion of tolerances in the DSA advisory in 104.1.1 is not intended for design, but it IS intended for construction and manufacturing.
So if the design (plans) say max. 40", and the as-constructed dimension is 40.01", then ADA / 11B-104.1.1 says that may be within conventional building industry tolerances and therefore allowable under ADA and 11B.

That doesn't mean that some enterprising litigant won't challenge it in court. But if it lands in court, then 104.1.1 provides the mechanism and context under which it may ultimately be deemed by the court to be in compliance with ADAS and/or 11B, even with an installed condition of 40.01" while the plans still say maximum 40".

OF course if you are the DPOR, you likely have the contractual right to reject a mirror at 40.01", even if the courts say it complies with the tolerances described in ADA.

Well hot damn, I was super wrong. I just spent an unhealthy amount of time going through a bunch of old federal cases and, yeah, judges have allowed what I would consider to be large amount of tolerance for what code considers "maximum" or "minimum". Up to 1 inch difference for most elements, even elements that are relatively easy to adjust like mirrors. Seems lenient to me since you should be able to construct what code calls for, but I'm not a lawyer.

Glad you posted this, because I would have taken the word "maximum" and "minimum" extremely literally until they changed the wording in code. Tbh, I probably still will because I'm a prick, but I won't be so anal about it lol.

 

[Yikes]

Well hot damn, I was super wrong. I just spent an unhealthy amount of time going through a bunch of old federal cases and, yeah, judges have allowed what I would consider to be large amount of tolerance for what code considers "maximum" or "minimum". Up to 1 inch difference for most elements, even elements that are relatively easy to adjust like mirrors. Seems lenient to me since you should be able to construct what code calls for, but I'm not a lawyer.

Glad you posted this, because I would have taken the word "maximum" and "minimum" extremely literally until they changed the wording in code. Tbh, I probably still will because I'm a prick, but I won't be so anal about it lol.

I posted it because I was also as shocked as you were!

Even with the availability of these construction tolerances, we all still have to decide on behalf of ours;eves and the property owners: Is our goal merely to prevail in court if/when it comes to trial?
Or is the better goal to design conservatively and avoid getting dragged into court in the first place, especially if you live in a litigious climate where everybody is looking for any excuse to shake you down for a settlement? That’s when it’s just better to move the mirror.

The court-appointed Neutral Accessibility Consultant (NAC) in the City of Los Angeles’s settlement on thousands of noncompliant city-funded public housing units has said that they will consider construction tolerances on a case-by-case basis. For the most part they will not pre-publish what they believe are conventional industry tolerances. Instead the will first note the measured noncompliance; then they will check the record drawings to see if the design was code compliant (no “design tolerance”); then the require the owner or contractor to submit a narrative on why they were unable to achieve the design tolerance.

Their goal is to make the process of accepting construction tolerances just onerous enough that we start getting complacent. I can appreciate that.

 

[arwat23]

This is the way I have always understood it. Minimum means minimum, not minimum plus-or-minus x.

That makes logical sense to me and that's how I will probably continue to operate, but apparently the DOJ disagrees.

From Access Now, Inc. v. Ambulatory Surgery Ctr. Group, Ltd. (S.D. Fla. 2001):
... "The evidence shows that mirror framing which is usually of an approximate 3/4" thickness results in a variation in the resulting measurement. Yet, the evidence also suggests that placement of mirrors at 40" above the finished floor to the reflective surface is based on the standard eye level range of adults seated in wheelchairs (43 to 51 inches). To allow a tolerance of two inches above the required height could preclude use of the mirror for a number of wheelchair users.

The Court finds that the Parties have agreed tat a variation of up to 3/4" for the placement of framed minors over accessible lavatories is acceptable. Otherwise, there is no conventional building industry tolerance for the placement of a lavatory mirror."


From Khan v. Kir Tampa (M.C. Fla. 2015):
"... The Plaintiff contends that the industry tolerances described in Section 104.1.1 do not apply to Sections 502.4 and Section 404.2.4.4 because the maximum slopes allowed under those rules are expressed in terms of a range. The Defendant, on the other hand, contends that the slopes allowed under Section 502.4 and Section 404.2.4.4 are expressed in terms of a maximum or minimum dimension, such that industry tolerances under 104.1.1 can apply. The Plaintiffs argument is based on the flawed premise that Sections 502.4 and 404.2.4.4 express their requirements in terms of a range between 0 and 1 :48. This is simply not the case. Sections 502.4 and 404.2.4.4 both state that "slopes not steeper than 1 :48 shall be permitted." Unlike Section 609.4, which requires grab bars to be installed between 33 and 36 inches above the floor, the requirements of Sections 502.4 and 404.2.4.4 refer to a single, maximum allowable slope; thus implicating the industry tolerances set forth in Section 104.1.1. As a result, the Plaintiff is not entitled to summary judgment as to Barrier Nos. 1, 12, and 27"


The above are from cases involving the ADA, not state code. I will probably stick with what's written in code because there's no specified standard tolerance and I refuse to be the one to tell someone something's within tolerance only to have them be sued.

 

[Yikes]

That makes logical sense to me and that's how I will probably continue to operate, but apparently the DOJ disagrees.

From Access Now, Inc. v. Ambulatory Surgery Ctr. Group, Ltd. (S.D. Fla. 2001):

From Khan v. Kir Tampa (M.C. Fla. 2015):

OK, I'm going slightly off-topic, but may I ask: how do you research and find these court decisions? Do you have access to a law library? Is their some online resource that has aggregated the court cases and their tolerance discussions for you? Do you use AI?

I Googled Kahn v. Kir Tampa and found this paragraph right after your quote above:

"The Defendant, on the other hand, is not entitled to summary judgment on Barrier Nos. 1, 12, and 27; albeit for different reasons. For starters, the Defendant's expert has not provided any detail regarding the range of appropriate industry tolerances applicable to Barrier Nos. 1, 12, and 27. Rather, the Defendant's expert has simply opined that the amount by which the slopes identified in Barrier Nos. 1, 12, and 27 exceeded the amounts allowed under Sections 502.4 and 404.2.4.4 are "minimal." Given the dearth of record evidence regarding the appropriate industry tolerances, the Defendant is not entitled to summary judgment as to Barrier Nos. 1, 12, and 27."​

So the expert witness failed to cite any "appropriate industry tolerance" during their testimony. This reinforces our discussion that although construction tolerances are available as a defense, it won't necessarily stop you from getting dragging into a trial to determine what is "appropriate".

 

[arwat23]

OK, I'm going slightly off-topic, but may I ask: how do you research and find these court decisions? Do you have access to a law library? Is their some online resource that has aggregated the court cases and their tolerance discussions for you? Do you use AI?

I use AI to give me a list of cases that might have something I'm looking for, then I Google search those cases or click on the links the AI provides and verify that the information I'm looking for actually exists. That's the only way I've been able to relatively easily find stuff like this. If I were to go just by Google search, I'd only ever find the bigger, more noteworthy cases, which often don't have the specific decisions I'm looking for.

AI has been maybe 75% accurate so far.

 

[arwat23]

So the expert witness failed to cite any "appropriate industry tolerance" during their testimony. This reinforces our discussion that although construction tolerances are available as a defense, it won't necessarily stop you from getting dragging into a trial to determine what is "appropriate".

Yes, that seems to be the case. Almost every document I looked at boiled down to "did the defendant prove construction tolerances could allow this variation?" So there's no recognized standard for these tolerances other than what courts have already ruled on. Even then, it's never a guarantee.

A mirror 40.25" off the ground might land you in court, but you probably won't be found liable.

 

[Yikes]

Yes, that seems to be the case. Almost every document I looked at boiled down to "did the defendant prove construction tolerances could allow this variation?" So there's no recognized standard for these tolerances other than what courts have already ruled on. Even then, it's never a guarantee.

A mirror 40.25" off the ground might land you in court, but you probably won't be found liable.

The reason I mentioned the Los Angeles NAC is that they are appointed by the court as part of the settlement with the city. When they make a determination on construction tolerance, it is essentially considered endorsed by the court for any project within LA city limits.
so far, they have been very reticent to publish their findings regarding construction tolerance, out of concern that it will be perceived as a license to be sloppy during construction.
The did publish a very lengthy study of the (in)accuracy of Smart Levels, and they determined that any reading of 2.4% or less will be ignored for surfaces required to be max. 1:48 slope; 5.3% or less will be ignored for main slope on walkways; and 8.7% or less will be ignored on ramps.

 

[arwat23]

The did publish a very lengthy study of the (in)accuracy of Smart Levels, and they determined that any reading of 2.4% or less will be ignored for surfaces required to be max. 1:48 slope; 5.3% or less will be ignored for main slope on walkways; and 8.7% or less will be ignored on ramps.

Any chance you could share that? I can't seem to find any mention of it when I Google search.

 

[ICE]

Accessibility code is an animal unto it's own. Ninety-nine percent of the dimensions that are found in all codes are the result of a committee consensus. Why they would be given immutable importance in the world of accessibility escapes me. The example of the 60" clearance suits how many disabled people? 58" is a deal breaker because? If anything there should be a buffer built in. If 60" is a hard and fast, absolutely got to have it, the dimension should be 65" with some wiggle room.

 

[arwat23]

Accessibility code is an animal unto it's own. Ninety-nine percent of the dimensions that are found in all codes are the result of a committee consensus. Why they would be given immutable importance in the world of accessibility escapes me. The example of the 60" clearance suits how many disabled people? 58" is a deal breaker because? If anything there should be a buffer built in. If 60" is a hard and fast, absolutely got to have it, the dimension should be 65" with some wiggle room.

In an ideal world, yeah. In terms of what I personally allow, yes.

 

[Yikes]

Any chance you could share that? I can't seem to find any mention of it when I Google search.

It was part of an annual 2-day seminar they give in the spring. I will see if I can find a copy of the PowerPoint.

 

[Jean Tessmer-HI]

Tolerances as applied to the actual execution of construction and specifications is complex, because you not only have the clear floor spaces and reach ranges, but you also have each feature and component, plus the the flooring smoothness and slip resistance, the slopes that need to be build-able by any contractor, and the operability of all of them working seamlessly together. You need to build in the buffers into all the designs and specifications so they all yield 100% accessibility according to the ADA and FHA. At the same time you don't want for instance, such low slope ramps that they end up consuming a lot of real-estate. I have scuffled with lawsuits by the DOJ over 1/16". Main streaming is the tough part. God bless you all for working on this.