Handwashing and Drying Area

Handwashing presents a special challenge for both accessibility and comfort. For example, a lavatory arrangement may meet accessibility requirements and even include low-flow water fixtures. But the reductions in water usage (and associated operations and water utility costs) may be offset by frustrated building occupants experiencing an outsize negative impact due to the specification—such as handwashing in an industrial setting, where low-flow simply may be inappropriate and even lead to wasted water. The same is often true for certain combinations of faucet-operating hardware and low-flow plumbing.

Ultimately, the best design will result first from establishing likely user habits before designing the lavatory. Second and as with all design efforts, thorough planning is essential.

ADA Guidelines

The ADA outlines certain requirements and clearances for lavatories and sinks. These include:

• The highest point of the rim or counter surface 34 inches above the floor

• Knee clearance a minimum of 27 inches between the floor and the bottom of the sink apron

• Knee clearance under the lavatory at least 8 inches deep from the front

• Minimum toe clearance of 9 inches above the floor

• Forward approach requires 30-inch by 48-inch clear floor space, as described earlier.

These and other guidelines address various configurations and possible overlaps in application. As an example, lavatories in commercial and institutional single-occupancy restrooms may not occupy the space above any portion of clear floor space for toilet access. Any exposed plumbing and hardware under the lavatory must be covered and protected, as exposed pipes cause injuries and burns to wheelchair users in some cases.

The ADA places requirements on installation of such items as soap dispensers, mirrors, towel rolls and dispensers, waste bins, and electric hand dryers. These are important minimums to follow, but they are insufficient to creating a high-performing restroom. Consider for instance what ANSI/ICC 117.1 requires for reach with respect to hand dryers and paper towel dispensers:

 

Operable parts on towel dispensers and hand dryers shall comply with Table 606.7.

 

This is crucial information, but it does not mandate the relationship between them, including distances between these elements and the lavatory or waste receptacle. It does not consider the issue of water on the floor, which can cause slip-and-fall accidents, or the experience of water dripping into one's sleeves or a wheelchair user's lap. Although a number of valuable recommendations are included, many other relationships are largely left to the architect's better judgment.

Health and Hygiene

Consider the design of restrooms for a workplace. Casual interaction between employees is responsible for much of the passing of contagions, which is why agencies like the Center for Disease Control (CDC) encourage employers to inform employees of the importance of hand washing. Research reported to the CDC indicates that educating employees on the importance of hand washing can reduce cases of diarrhea by 31 percent (58 percent for those with weakened immune systems) and respiratory illnesses like colds by 21 percent.³ This is due in part to the fact that, as some research indicates, as few as 31 percent of men and 65 percent of women wash their hands after using public bathrooms.⁴ In addition, research by Leeds University and Bradford University has shown that a person with dry hands is about 1,000 times less likely to cross-contaminate other people. Clearly, getting hands clean—and dry—is very important.

If illnesses can be avoided, not to mention injuries from accidents that could arise from slips on wet floors, this translates into safer work environments for employees and more productive workforces, which would certainly benefit the employer. This provides yet another reason to consider likely user habits, best practices, and technological advances in bathroom furnishings before finalizing a restroom design.

Again, it is always advantageous to reduce the space between sinks and drying options to reduce the amount of water on the floor and the associated mold, bacteria, slip hazards, and the like. As for which drying option to choose, at least one recent study in the U.K. suggests that paper towels are more hygienic than dryers,⁵ but this ignores the problem of paper towel waste cluttering the restroom, which is itself unhygienic. It also ignores the practical matter of user habits: A restroom user would have to ring each finger to achieve the same level of dryness as achieved by today's air-knife-type hand dryers, which achieve the NSF standard of 0.1 grams of water.

Also, the U.K. study fails to distinguish between warm-air and high-speed dryers, according to experts. Warm-air dryers can harbor microbes, offering an environment in which they can thrive and multiply. High-speed dryers using HEPA filtration are shown to capture at least 99.97 percent of bacteria from the air being used to dry hands, which the National Sanitation Foundation protocol NSF P335 (“Hygienic Commercial Hand Dryers”) establishes as a working definition of “hygienic” for dryers. There are other reasons to consider the new hand dryer technologies. For example the novel air-knife designs eliminate the “catchbasin” element of some trough-style hand dryers and moves a stream of air that is powerful enough to atomize water into vapor. Hand dryers with a drain cartridge do not share the issue of trapping water, as with a trough-style device.

Sustainability

A number of issues factor into making sustainable design choices in restroom design, most of which fall into one of two major categories: whether they contribute to healthy indoor environmental quality (IEQ), positively impacting occupants and visitors, and whether the choices sufficiently reduce their potential for negative impact on the planet.

Improving the IEQ of restroom environments can come through detailed research into specified elements. For instance, not only should finish materials be low- or zero-VOC-emitting, but the same should be true of cleaning supplies regularly used by maintenance staff. Restroom design that eliminate or reduce opportunities for microbes to thrive or be transmitted are crucial to positive IEQ. Around the lavatory these strategies include eliminating paper towel waste, specifying dryers without heating elements, and removing requirements for touching operable elements. This latter option is especially important: The American Journal of Infection Control has reported that microbes can survive on many surfaces for up to 72 hours.⁶ Eliminating the need for touching surfaces makes the relative success of each instance of washing more likely to successfully sanitize hands.

Of course, specification of automatic, touchless fixtures and accessories—such as faucets, soap dispensers, hand dryers, and towel dispensers—must include some research into operations failure rates. Fixture or accessory failure will encourage users to touch the elements in hopes of activating them, and potentially will discourage the washing hands in the first place. In general, however, touchless bathroom elements are not only the most hygienic option, but also frequently the most conducive to universal, accessible design and ADA compliance as well as sustainable design. In fact, new LEED versions include credits awarded for universal design, such as the recently piloted Credit 34, Design for Adaptability.

Making sustainable choices in bathroom elements also requires consideration of such issues as embodied energy, atmospheric carbon, output to landfill, and so forth. On a global level, the impact of drying option selection could have a significant environmental impact in aggregate.