Master Bathroom Traffic Flow

There probably is no greater challenge in the interior design field than planning a master bedroom suite and getting the perfect traffic flow for every client. Unlike a traffic circle or major intersection where every driver is familiar with protocol and flow, master bathrooms present unique challenges. Homeowners who awaken and depart to different jobs at the same time present different requirements than those who use the bathroom at different times. In either case, future usage requirements must be considered.

It would be wrong to say there is a perfect solution for every project. Existing plumbing, unmovable walls, adjacent rooms and hallways will be major influences. Also, the homeowner’s willingness to modify these areas relative to the investment expectation must be factored into the equation. By recognizing a few basic human preferences and personal-hygiene factors, a solution that accommodates owners’ preferences and the structure’s limitations can be achieved.

Toilet Enclosures

Many master bathrooms include a separate toilet enclosure. This room should be a minimum of 36-inches wide by 66-inches long. The suggested centerline for a toilet from a wall is 18 inches with centerline of an adjacent bidet being no less than 18 inches from the side of the toilet. IRC and IPC codes permit closer dimensions. Your clients’ desires for space should dictate. When specifying a toilet/bidet combination, do not forget to provide a soap dish and towel holder in the enclosure.

Tub and Shower

The relationship of the shower, tub and lavatories is relatively simple and a common entrance/drying area often is the best answer. I have found that in very large spaces, more area dedicated to the bedroom or closets is much more appreciated than a big “dance floor” in front of a tub or shower.

Consider specifying an under-mounted tub. This promotes a clean look and easy entrance and exit from deeper units. Avoid steps into the tub for safety reasons, though a ledge over the deck surface can be used as a design feature and to store soaps and lotions. I suggest at least 4 inches of deck surface on all four sides and more if possible along the front edge to provide a seating area for easy entry into the tub.

A central location for a large tub is preferable because it allows for an adjacent shower to share part of the deck as a seating area within the shower and adds to the overall aesthetic of the room.


Dual vanities are common in a master suite, though little consideration is given to elbow room and traffic flow. When placing vanities across from the bathing area, a minimum of 30 inches of clear floor space is recommended. In a master suite, 36 to 50 inches is common.

The minimum code requirement for dual lavatories is 60 inches overall with the lavatory bowls on 15-inch centerlines from the ends. The Hackettstown, N.J.-based National Kitchen and Bath Association recommends 76 inches. This combines the minimum centerline of 20 inches from a wall or end of a top with the minimum distance between centerlines of 36 inches.

Final Suggestions

Seasoned professionals recognize there are many more ways to solve master bath challenges. Don’t forget to rely on publications from NKBA, particularly the “Bath Planning” volume of the Professional Resource Library and the Kitchen & Bathroom Planning Guidelines with Access Standards. Finally, read and study designers of note, become active in your local professional organizations, and seek out the expertise of those who share their experience through publications and networking.