ADA design considerations in non-residential showers

By Caleb Kline, Mazzetti

Since its passage in 1990, the Americans with Disabilities Act (ADA) has increased the accessibility of the nation’s buildings and improved the lives of those living with disabilities and the general population as a whole. While most ADA standards are primarily the responsibility of the architect, plumbing fixtures require coordination between the plumbing engineer and the architect to ensure compliance. 

ADA showers in nonresidential buildings have several standards that are commonly overlooked by both parties. These noncompliance issues may not be noticed by code reviewers or inspectors, but will be noticed by the first person with limited mobility who attempts to use the shower. 

Better awareness of the ADA standards and coordination between plumbing engineers and architects can prevent building owners and designers from facing noncompliance lawsuits. More importantly, it can prevent discrimination against individuals with disabilities.

Since the ADA is a civil rights law and not an official building code or organization, the enforcement of ADA compliance is managed differently than many other building code requirements. Noncompliance legal matters are filed against building owners by the Department of Justice (DOJ) or private citizens. Another issue that designers may not be aware of is that there is no organization that certifies ADA listed products. 

Products labeled ‘ADA Approved’ may or may not actually be compliant. The International Building Code (section 1101.2) does specify baseline criteria for accessibility based on ICC A117.1, Accessible and Usable Buildings and Facilities (previously known as ANSI A117). The 2010 ADA standards were based on the 2003 ANSI A117. The two have nearly identical structure and content, though the current version of ICC A117.1 is more stringent in some places.

Chapter six of both documents governs accessible plumbing elements and facilities. Like other plumbing codes, the ICC A117.1 / ADA was established to improve building safety and functionality for its occupants.   

The 2010 ADA Standards, Chapter Six defines several types of accessible bathtubs and showers. Transfer showers are most commonly used in nonresidential buildings because they have the smallest footprint. A person in a wheelchair would access a transfer shower by transferring sideways from the wheelchair to a built-in shower seat. Section 608.2.1 requires that a transfer shower compartment have 36 by 36 inches inner dimensions. 

While transfer shower compartments with larger dimensions may be sold with a seat and grab bars, they are not technically ADA compliant and should not be listed as such by the manufacturer. More space in the shower may seem like a benefit but can actually hinder the seated user from safely reaching the shower controls. Figure 1 shows the dimensions of a transfer shower compartment and the required immediate outer clearance. Even though the architect usually provides the clearance in front of ADA showers, the plumbing engineer should habitually double-check them. 

Another common design oversight is shower head location. As shown in Figure 1, the 48 inches of clearance is measured from the control wall (i.e. the wall with the shower head). A properly positioned wheelchair requires 12 inches of clearance behind the seat wall. If a stall divider was installed in line with the control wall in Fig. 1, the total clearance would then be 48 inches. If the shower head was installed in Fig. 1 on the wall labeled “seat wall,” and the seat was installed on the wall labeled “control wall,” the seat would be located opposite the clearance, preventing wheel chair access. The architect or drafter placing the showers in the project backgrounds may not be attentive to this requirement. 

Coordinate with the architect which shower stalls they are designating as ADA compliant and ensure that the shower seats are oriented correctly in the backgrounds. You may even wish to specify the shower head locations on the drawings. If you are using a pre-manufactured shower assembly, be sure to note during the submittal review that the contractor shall order right or left handed models to meet ADA requirement as shown on the drawings.

The shower threshold on ADA showers must also be coordinated between the architect and the plumbing engineer. Section 608.7 requires that thresholds on transfer type showers be a maximum of 1/2 inch high and be beveled, rounded, or vertical. (Refer to the standards for an exception for existing facilities.) Prefabricated, ADA labeled shower basins should have compliant-sized thresholds, although as mentioned above it is up to the designer to double-check. 
The installation of compliant, prefabricated basins often requires that they be recessed into the floor, or that the shower room floor be built up to them.

Again, this requires early coordination with the architect and possibly the structural engineer. Since a ½-inch threshold will not retain a large quantity of water, a wise design practice is to slope the outer floor to a drain. This can be done by sloping the floor away from the shower threshold towards a floor drain or, for a more seamless design, sloping the outer floor toward the shower and providing a shower pan with no threshold. This design allows any splashed water to flow back to the shower drain (see figure 2). Be sure to limit floor slope to ¼ inch per foot at most.

One of the most overlooked ADA shower requirement is the location of the shower controls and hand-held spray unit. ADA standards’ section 608.4.1 requires that controls, faucets, and shower spray units be installed between 38 and 48 inches above the shower floor and 15 inches maximum from the centerline of the control wall toward the shower opening. This height range places all the controls above the grab bar required on the control wall but within reach of the average seated person. Despite the standard’s clear language, many installation manuals for ADA listed shower systems do not adhere to this critical mounting height. 

One such installation guide required the temperature control knob to be located 48 to 54 inches above the shower floor, with the diverter valve 12 inches above the knob. If installed following these instructions, the diverter valve handle and possibly the control knob would be out of reach of a seated user. Most “ADA” shower systems have the spray unit mounted so that it slides along a 24- or 36-inch grab bar. As long as the bottom of this bar is no higher than 48 inches, the installation is technically compliant. However, as soon as someone slides the hand-held unit up the bar, it becomes out of reach for a seated person. A better design would be to specify that the spray unit be held on a wall-mounted bracket located 38 to 48 inches above the shower floor. See figure 3 for an example of a compliant shower control wall. Plumbing engineers should carefully detail or specify the locations of shower controls in their designs.
Early coordination of the access, shower head and controls locations, and thresholds for transfer showers is key to ensuring ADA compliance. The ADA standards contain additional items pertaining to showers and other plumbing fixtures. These standards are written in plain language with descriptive figures.

They are more accessible than most standard codes. The ADA National Network is another resource for technical assistance regarding ADA building construction. I highly encourage all plumbing engineers to reference the ADA standards early and frequently, coupled with early project team coordination to avoid preventable noncompliance issues.

Caleb Kline is a Plumbing Designer for Mazzetti, a global MEP design and consulting firm, primarily in the Healthcare sector. Kline is based in Denver, Coloradoand can be reached via phone 720.644.5043 or email

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