"I was for the war before I was against it..."

In the ADAAG there are rules that might appear to be inconsistent.  Sometimes there are rules for the same space or fixture that have different requirements depending on where they are found.  Here are a few examples:

Grab Bars

Grab bars at water closets that are not in a stall follow fig. 29, which specifies a minimum of 54" from the back wall to the edge of the grab bar

But for the same grab bar that is found in a stall or toilet compartment, the length required is 52" minimum per figure 30d.

Sinks and lavatories

A sink is a plumbing fixture not found in a restroom or used for other things than washing hands, whereas a lavatory is typically found in a restroom and is only used to wash hands.  The knee space requirements for each is slightly different.  For a "sink" the knee space requirement is 30" wide and 27" tall to the underside of the apron. 

At a lavatory, though, the knee space requirement changes to 29" below the apron per Fig. 31

Counters

Depending on where you find a "counter" there is a different height requirement.  If the counter has a sink, then the height is 34" high maximum. 

There are also knee space requirements that are not provided in the picture above, but the height of the counter was acceptable.

A transaction counter at a retail store, or a beverage counter at a restaurant or a counter at an eating establishment or bar, can be placed at 36" maximum above the finished floor.

Counters located at employee work areas are not required to adhere to the guidelines.  These are exempted except for the ability to approach the work area, enter it, turn around and exit.  The elements within the work area are not required to comply.

It's sometimes difficult to be cognisant of all the nuances of the Guidelines, but when designing, it is important to note, that not all requirements are created equal and it does depend on how the elements are used on whether or not they have dfferent rules and standards.

Why argue? This sink is not accessible!!!!

Sometimes in the accessibility guidelines and standards there might be figures that are vague and could be interpreted in different ways.  Then there are very clear rules where there is no question what the requirments are.

Figure 31 of the ADAAG shows the clearances that are required under a lavatory or sink

There are several dimensions that let you know how much space there should be provided so that the wheelchair user can fit under the sink.  Notice the 8" min horizontal dimension from the front of the sink back towards the bowl.  There is no question that this 8" is a requirement.

I performed an inspection where this 8" was ommitted.  The photo below is of the sink in question.

The architect had drawn the correct drawing which showed the 8" horizontal for the knees.  Lucky for me, I brought the drawings with me to show the Owner.  The contractor argued.  He said that this was sufficient for a knee space.  Of course this is not acceptable and they will have to fix it (and hopefully the Owner will not have to pay for the fix since it was the contractor's mistake).

Why argue?  It is clearly not built per Fig. 31 and there is no question that the 8" was not provided.  This profile will not be able to be accessed by a wheelchair.  So just fix it!!!!