Bath Ergonomics

Planning the simplest 5'x7' bathroom so that it reflects the client’s lifestyle can be a challenge. Despite the limited space, the prospective client hopes for a great bath packed with convenience, safety and grace. Likewise, clients planning a master suite have visions of a spa retreat that may not fit either their available square footage or their budget.

As we planners work with the “dream bath” wish list, we need to be ever vigilant about making the bath a good fit for the user while being thoughtful regarding the space and storage requirements.

So let’s talk about the basics of bathroom design before we focus on the special details the clients hope you can fit in – all while staying within the available space and investment figure reserved for the project.

Successful bathroom designers begin planning any bathroom space with a careful information gathering program. That means finding out who will use the space, how it will be used, what fixtures are required, what look pleases the client, what construction constraints exist…and what budget or investment figure is available.

In small spaces, designers sometimes make the mistake of seeing the space as an impossible design challenge. They simply suggest retaining the three fixtures in their existing locations and adding a little “pizzazz” along the vanity wall.

Another mistake designers make is assuming that their prospective client uses the bathroom just as they do. By mistake, the bathroom planner transfers his/her preferences and value systems to the prospective client as they sit at the drafting board or in front of the computer and begin the conceptual space-planning process.

For NKBA members, there is a great tool: an information gathering form that is part of the Business Management Form System. Accessible at, this “member only service” is available for download at no charge.

Another great resource for designers who are attempting to really personalize the space for the intended user is Human Figure Ergonomic information based on the American Form published by Architectural Graphics Standards.

We have included this dynamic dimensional information for review.

Clearly, as a designer begins the planning process, focusing on “average” is not the best approach. However, being familiar with this information is a good starting point, allowing the design professional to note the client’s human form dimensional considerations.

Available information covers everything from the appropriate depth for a shower bench to typical users’ eye levels calculated when locating wall-mounted light fixtures – and even how much clear space is needed for one to “towel off.”

Knowing the user’s physical form dimensions is just a beginning. Knowing who will use the space you are designing and how it will be used is next.

Who's Using the Space?

Identifying who will use the space is the planner’s first job. It may be a family bathroom, a child’s bathroom, an adult retreat/master suite or a guest bathroom.

If the space is used by the entire family or exclusively by children, find out what the schedule is. Does the family use the bathroom individually, following a staggered schedule, or is the space shared by several people as they prepare for the day each morning? For adults, do the owners prefer privacy or company while grooming? Would they like the bathroom open to the bedroom or set apart and private?

In addition to such comfort questions, the planner should keenly observe any physical limitations of the user. A whole other topic: Special attention must be given to a space planned for an aging or physically handicapped individual.

How the space will be used is a good question to ask. Planning an “adequate” bathroom is just not enough for today’s consumer. Just as the chef’s personal cooking style affects the kitchen cabinet plan, the intended plan – or dream – for the new bathroom guides the planning process. To create a personalized space: Identify how the bathroom will be used. Prospective clients seem to fall into several lifestyle categories:

  • One group sees the bathroom as a “quick in and out” bathing space. Users then return to their bedrooms to complete the grooming process. This is the typical approach when one bathroom is shared by several family members.
  • Another group dreams of a bathroom that is both a bathing and a grooming center. Users stumble into the bathroom in the morning and do not emerge until they are ready to face the day – hair, face and nails in perfect order.

Wise designers also try to determine the grooming philosophy shared by the family. Do the prospective clients appear to be naturalists who are satisfied with a quick brush of their hair and a swipe of lip gloss? Or, do they appear to be people who purchase every conceivable beauty aid for sale? Do they tend to collect a variety of grooming aids or concentrate on a favorite few? Do family members share equipment or maintain private sets? Are the bathroom staples, such as toothpaste or toilet paper, purchased in large quantities or just as needed? Using the NKBA information gathering questionnaire will help obtain this important information.

Human Anatomy Considerations

Historically, bathroom design has focused solely on the space required for the three basic fixtures: the lavatory (sink), toilet (water closet) and bathtub (bathing pool) and/or shower enclosure.

Clients today clamor for a bathroom that is designed with people in mind – not fixtures. For example, when working with a small space, always consider whether your client is right- or left-handed. Provide the majority of countertop space on the right side if the client is right handed and on the left side if the client is left handed. When limited to a 36" to 48" vanity top, this information is crucial. Two small landing areas on each side of a centered sink are not nearly as useful as one larger space positioned to suit the user’s handiness.

The National Kitchen and Bath Association also has an excellent set of guidelines published for bathroom planning that includes minimum and maximum recommendations based on nationally accepted codes, as well as industry experience. Make sure you are familiar with them so that you have industry information when considering: standing space in front of a lavatory, tub or shower; wall space or knee space for using a toilet or a bidet; proper placement for bathroom accessories such as the toilet paper holder, grooming recesses in showers/tubs and grab bar installations.

Following are some key points.

In the Toilet Area: The toilet paper holder should be installed slightly in front of the edge of the toilet bowl. Smart designers specify a recessed toilet holder in a narrow space. When using surface-mounted toilet paper holders, the overall dimension of the accessory’s protrusion from the wall must be determined – to make sure it does not become an “accident waiting to happen.”

For the Bathing Pool Area: Although these guidelines have been long-standing, these are the areas I see continually overlooked.

  • Realize the user needs to access the tub’s filler controls from outside the tub, and exit the tub with wet feet.
  • The primary concern for ergonomically safe planning is the height of the platform, the distance from the edge of the platform to the interior tub and the left and right space for the user to be seated first, before swinging his or her legs into the tub.
  • Ideally, tubs should never be recessed in the floor, should never have steps leading up to them and should be carefully positioned regarding the overall finished height based on the client’s stature. Wherever possible, tubs should be under-mounted, allowing for naked bathers to sit on an even-surfaced deck and swing their feet in. Non-skid floor surfaces outside of the tub area are a must. Keeping the controls to the front of the tub – but positioned left/right – as opposed to at the back of the tub provides safe accessibility.

In the Shower Enclosure: Many manufacturers can provide excellent details about how to create a shower that features a variety of water experiences. When we consider the human form in the shower, here are some key points.

  • When using an overhead rain showerhead, do not position the drain immediately below the rain head: The user will stand on the drain and flood the shower.
  • When considering a trough drain in a second floor installation, work with the installers to determine how you are going to raise the bathroom floor height, allowing you then to slope the shower to the trough drain.
  • A bench or foot rest is a must. I am distressed at how often I see a luxurious shower enclosure with no place for an adult to be seated – or at least rest their foot.
  • If you are planning a steam shower, familiarize yourself with the porosity levels of the surround materials specified, and remember to lower the ceiling – and slant it. Realize that the bench may need to be wider if the principal steam shower user plans on lying down and enjoying the experience. Keep the steam generator head away from the user’s feet – a challenge in small, enclosed showers.
  • And, yes – start including grab bars in every shower that you plan.

Design Details

When it comes to design details, I suggest you consider the following:

  • We often see wonderful bathing pools with delectable chandeliers above them. Check with your local code before specifying such a fixture. Some states do not allow a light fixture above a water fixture at all. Others allow a fixture above the tub, but list specific criteria from the finished floor to the bottom of the fixture. Find out what the rules are in your community.
  • Lights placed on each side of a vanity need to be located based on the principle user’s height, as well as the design of the fixture. The light source should be placed at or near the user’s face/cheek level. This can be tricky because many fixtures have an electrical connection that is not in the center of the fixture.
  • Always consider a heated floor in a bathroom space so that a nude user can enjoy a room that is warmer than the balance of the living areas planned for a clothed individual.

The Storage System

I always enjoy seeing beautiful bathrooms created by many of our respected fixture manufacturers. However, I must admit to being a bit perplexed about where all of the homeowner’s “grooming paraphernalia” is stashed when I see an elegant master bath with architecturally stunning lavatory consoles.

When there is no storage in or around the lavatory (sink) area, separate tall storage, a closet or other areas should be planned.

Flooring and Surfaces

Mentioned before – but so important – permit me to remind you that non-skid surfaces need to be planned for the floors. Indeed, a non-skid surface should be planned for the shower bench as well. Slippery surfaces, the lack of handrails/improper installation of grab bars, surface-mounted soap dish containers and faucets that do not control water temperature shifts are the greatest causes of accidents in the bathroom.

Consider honed or textured bench surfaces for the bather sitting in a slippery shower, or someone exiting the tub or shower and walking across the floor.

Planning a bathroom space starts with knowing who the user is, what the design preferences are, what favorite products have already been researched and what the budget is. Making a “good” bathroom “great” happens when the design professional spends extra time personalizing the space for the users’ morning grooming activities, storage needs and physical stature, while also being keenly focused on creating a safe environment.

Ellen Cheever, CMKBD, ASID, is a well-known author, designer, speaker and marketing specialist.

A member of the NKBA Hall of Fame, Cheever gained prominence in the industry early on as the author of two design education textbooks. She manages an award-winning design firm, Ellen Cheever & Associates, and has been part of the management team of several major cabinet companies.

This article is part of a quarterly series of “Designer’s Notebook” articles, which will continue to run throughout 2011 exclusively in Kitchen & Bath Design News.