The Illustrated Rules of Good Bathroom Design

The National Kitchen & Bath Association developed the Bathroom Planning Guidelines to provide designers with good planning practices that consider the typical needs of users.

A committee of experts in bathroom design reviewed relevant research, lifestyle, and design trends, and Model Building Code requirements to assure the updated guidelines promote the health, safety, and welfare of consumers.

A bathroom that follows all of these rules is almost guaranteed to be both functional and safe. See how many your existing bathroom violates for a better understanding of why it may seem awkward and dysfunctional.

These guidelines are not the only bath design rules, however.

Designers and con­trac­tors have worked out some rules of thumb over many years that do not rise to the level of official national standards but represent a distillation of years of experience and generally accepted industry practice. We have included these in comments where applicable.

The NKBA guidelines are used for academic and educational programs in bathroom design, evaluation of bathroom plans, and testing the competencies of designers seeking certification. For more information and to locate an NKBA member in your area, contact The National Kitchen and Bath Association.

What Do These Fonts Mean?


The verbatim text of an NKBA guideline recommendation.

Code Re­quire­ment:

Refers to the International Residential Code (IRC) and associated plumbing, electrical, mechanical and access codes. Where appropriate, the requirements of the Americans with Disabilities Act are also indicated. These are taken from Standards for Accessible Design published by the U.S. Department of Justice. Most ADA standards do not apply to private residences. But if you are building or remodeling for a person with limited mobility, they provide a good template for how things should be built. Your local code authority may have modified or added to national requirements, so always check with your local code authority before making any changes to your bathroom


Are remarks by the publishers of the rule, standard or guideline used to clarify or expand the standard or guideline.


Are our observations and explanations. If we want to clarify or expand on a guideline, this is where we will do it. We will also use comments to introduce recommendations and rules-of-design that are not a part of the guidelines published by the NKBA.

The clear opening of a doorway should be at least 32". This would require a minimum 34" or 2'-10" door. For universal design, the minimum clear width is 34". If the existing structure precludes changing the opening then a minimum 24" or 2'-0" door is allowable.
The door opening width is measured from jamb to jamb. The clear opening width is measured from the inside of the open door to the door stop on the other side of the opening. It is almost always about 2" narrower than the clear opening. The doorknob is disregarded when calculating a clear opening.
  1. Clear openings of doorways with swinging doors shall be measured between the face of the door and stop, with the door open 90 degrees. (ANSI 404.2.3) If the door can open a minimum of 93 degrees, the handle may be disregarded in measuring the opening.
  2. When a passage exceeds 24" in depth, the minimum clear opening increases to 36". (ANSI A117.1 404)
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. The International Residential Code is silent as to door widths and heights of interior doors. Many communities have, however, supplemented the basic code by requiring a minimum 30" door opening in most rooms, 24" for bathrooms, at least one 36" exterior door, and a minimum door height of 6'-8" (80"). For bathrooms complying with the Americans with Disabilities Act (ADA), the clear door opening must be 32" wide with the door fully open which usually requires a 34" wide door at a minimum.
  2. Standard door widths include 18", 20", 24", 28", 30", 32" and 36" doors. Any other width and any door wider than 36" is generally made as a custom door.
  3. To achieve a clear opening, the door size must ordinarily be at least 2" larger. For example, a 32" clear opening requires a 34" door, and a 36" clear opening requires a 38" door.
  4. Since a 34" (2-10) interior door is typically a special order custom door, this standard is usually met with a 36" (3-0) standard door. A 36" opening for a narrow passageway requires a 38" door to meet the requirements of ANSI A117.1 404. These are not available except as custom doors – so narrow passageways should be avoided where possible.
  5. In a bathroom remodel, codes generally do not require an existing door to comply with current minimum opening widths but if the door is moved as part of the bath remodel, then most jurisdictions will require that current code minimum opening standards be met.
Guideline: No entry or fixture door should interfere with another door or drawer and/or the safe use of the fixtures or cabinets.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. The entry door should not interfere with a shower door or any cabinet door or drawer.
  1. The entry door should not interfere with a person using any bathroom fixture or appliance.
  2. We commonly find entry and shower doors arranged so they will strike anyone standing in front of the vanity or sink or sitting on the toilet.
  3. In remodeling bathrooms, especially small baths where space is at a premium, the entry door should, if at all possible, swing out, not in. This not only eliminates door interference within the bathroom but for small baths, adds useful space inside the bathroom that was formerly taken up by the door swing.
Guideline: Same as Building Code Re­quire­ment.
Building Code Re­quire­ment: Bathrooms shall have a minimum floor to ceiling height of 80" over the fixture and at the front clearance area for fixtures. A shower or tub equipped with a shower head shall have a minimum floor to ceiling height of 80" above a minimum area 30" X 30" at the shower head. (IRC R305.1.4)
  1. The general code requirement is that ceilings be at least 90" (7'-6") high but an exception is made for bathrooms that are required to be only 80" (6'-8") high. In any place where a person cannot walk, the ceiling may slope or be dropped down to as low as 60" (5'-0"), and most code officials will allow an even lower drop, especially in bathroom remodels, if it is safe and reasonable under the circumstances.
  2. The requirement that a shower be at least 30" x 30" x 80" at the shower head is merely practical. Much smaller and the average person would not fit. It is difficult to find a pre-made shower cabinet this small. The usual minimum size is 32" x 32".
  3. The minimum height of 80" (6'-8") "over the fixture" includes the required minimum clear floor space in front of the fixture, which must also have a minimum height of 80" (6'-8"). See Guideline 4.
  4. This Guideline must be coordinated with Guideline 9.
  5. In remodeling bathrooms, this Guideline will have the most impact on bathroom remodels in basements, attics or garrets were ducting or the slope of the roof may reduce the ceiling height over some part of the remodeled bath.
Guideline: Plan a clear floor space of at least 30” from the front edge of all fixtures (i.e., lavatory, toilet, bidet, tub, and shower) to any opposite bath fixture, wall or obstacle.
Building Code Re­quire­ment:
  1. A minimum space of at least 21" must be planned in front of lavatory, toilet, bidet, and tub. (IRC R 307.1)
  2. A minimum space of at least 24" must be planned in front of a shower entry. (IRC P 2705.1.5)
  1. Where possible use the recommended 30” minimum clear space when remodeling a bathroom. For many people, especially those with limited movement, the 24” or 21” code minimum is too small.
  2. When remodeling bathrooms just 5' wide, which is most baths built from 1945 through 965, the smaller 24” and 21” clear space minimum standard may be unavoidable.
  3. One way to increase clear space in a bathroom remodel is to reduce the space occupied by fixtures by reducing the size of the fixture. For example, the standard 21” vanity depth can be reduced to as little as 15” with proper planning.
  4. It is often possible to create more clear space when remodeling a small bathroom by reversing the swing of the bathroom door so it swings out, not in. See Guideline 3.
  5. The clear floor space around a pedestal or clawfoot bathtub should follow the general rule for bathtubs with the following addition: the clear space between an edge of the tub and any adjacent wall or fixture should be a minimum of 4" to allow for cleaning behind the tub – 6" is better. The entry side of the tub should have a minimum of 21" of clear floor space, 30" is better.
  6. For techniques useful in remodeling a bathroom to create more clear space, see "Getting More Bathroom Space".
Guideline: The distance from the centerline of the lavatory to the sidewall/tall obstacle should be at least 20”.
Building Code Re­quire­ment:
  1. The minimum distance from the centerline of the lavatory to a wall is 15". (IPC 405.3.1)
  1. The minimum distance between a wall and the edge of a free-standing or wall-hung lavatory is 4". (IRC R 307.2)
  1. A pedestal or wall-mounted lavatory must meet both of the Building Code Re­quire­ments.
  2. a. The center of the lavatory must be at least 15" away from any side wall or tall obstacle, such as a tall cabinet, and
  3. b. The edge of the lavatory must be 4" from the wall or tall obstacle.
  4. c. This means that the maximum width of the sink cannot exceed 22".
  5. There are practical reasons for the 4" requirement. Any closer and it would be very difficult to clean the sink or the wall behind the sink.
  6. In a small bath remodel, careful attention needs to be paid to the size of lavatory sinks to ensure that minimum offset distances are met. When in doubt, go smaller. Almost all fixture manufacturers make lavatory sinks designed to fit very small spaces.
Guideline: The distance between the centerlines of two lavatories should be at least 36".
Building Code Re­quire­ment:
  1. The minimum distance between the centerlines of two lavatories should be at least 30". (IPC 405.3.1).
  2. The minimum distance between the edges of two free-standing or wall-hung lavatories is 4". (IRC R 307.1)
  1. In addition to this requirement, double lavatories must meet all the setback requirements of single lavatories. See Guideline 5.
  2. In small bathroom remodeling, careful attention needs to be paid to the size of lavatory sinks to ensure that minimum offset distances are met. When in doubt, go smaller. Almost all fixture manufacturers make lavatory sinks designed to fit very small spaces.
Guideline: The height of a lavatory or vanity top varies between 32"-43" to fit the user.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. This Guideline recognizes that the standard 32" or 36" vanity height is not appropriate for most people.
  2. The former practice of installing 32" vanities as a compromise between the best height for children and the best height for adults has fallen by the wayside as builders recognized that after children are grown, adults are stuck with a too-low vanity height for many, many years.
  3. The current better practice in remodeling a bathroom is to install a factory-standard 36" vanity, which is better but still too low or too high for most people.
  4. If young children are using the vanity, rather than lowering the vanity, buy a stool.
  5. However, the best practice in current bathroom remodels is to determine lavatory height based on the height of the user, and adapt the height of the lavatory to the user rather than requiring the user to adapt to the vanity height. For more information on ergonomic design see, "Body Friendly Design".
Guideline: Specify clipped or round corners rather than sharp corners on all countertops.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. This Guideline applies only to exposed outside corners. Corners that abut a wall or another cabinet need not be rounded or clipped.
  2. In remodeling a bathroom, especially where space is at a premium and clear space is at a minimum, clipping or rounding countertop corners is very important to prevent injury is a sharp corner is accidentally struck.
  3. Every material commonly used for a countertop can be either clipped or rounded For more information on countertop materials used in bathroom remodeling see, "New and Traditional Countertop Materials".
Guideline: The interior shower size should be at least 36" x 36".
Building Code Re­quire­ment: The minimum interior shower size is 30" x 30" or 900 square inches, in which a disk of 30" in diameter must fit. (IRC P 2708.1, IPC 417.4).
  1. A shower may be of any shape, as long as:
    • A disk 30" (36" recommended) in diameter will fit within the walls of the shower and,
    • The shower head is inside the disk area. (This is something that does not appear in the building code but is in the plumbing code in most localities.)
  2. Generally, to meet the code minimum size, a corner shower with an angled door (neo-angle door shower) cannot be any smaller than 32" x 32". A 30" disk will not fit inside the walls of a 30" x 30" neo angle shower. A minimum neo-angle shower size of 36" x 36" is recommended if space is available.
  3. The smallest pre-fabricated shower available from most manufacturers is 32" x 32". This dimension is from stud to stud, so it may finish out to less than 32" x 32". A 30" disk will just fit inside the walls of this shower.
  4. In a very small bath remodel, this minimum may still be too large. But, before you go any smaller, check with your local code officials. Sometimes, if a need for the shower can be demonstrated, they will allow a slightly smaller finished shower.
  5. This Guideline must be coordinated with Guideline 3.
  1. The shower controls should be accessible from both inside and outside the shower spray and be located between 38"-48" above the floor depending on the user's height.
  2. The tub controls should be accessible from both inside and outside the tub and be located between the rim of the bathtub and 33" above the floor.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. The guidelines are silent on the issue but when we remodel bathrooms, we have always assumed that the height of controls is measured to the vertical center of the control.
  2. The common practice in most bath remodels is to install shower and tub controls on the centerline of the tub or shower. This means that to turn on the shower or adjust the water temperature, it is often necessary to reach through the shower water. The better practice is to offset shower controls toward the opening of the shower so that the shower can be adjusted without reaching through the water.
  3. In a tub, the same outboard offset makes it unnecessary to lean into the tub to turn on the water or adjust water temperature, this reduces the risk of slipping or losing balance and falling.
  4. While the Guidelines do not prohibit centerline installation so long as the controls can be reached easily from both inside and outside the tub or shower, we know of no situation where that is really possible.
  5. The shower control heights specified by the guidelines are a little rigid. Showerheads should be set at the most comfortable height for the user. If there are multiple users, then a compromise is in order. As a guide, here are the heights we use in our bath remodeling. For multiple users, we use the average height of the users. Do not include children in height calculations.
User Height 5' 5'-3" 5'-7" 6' 6'-3" 6'-6"
Shower Controls 38" 41" 44" 47" 50" 53"
Shower Head 68" 73" 76" 80" 83" 86"
*Measure to the vertical center of the control. For a wall-mounted showerhead, measure to the vertical center of the shower arm where it meets the wall. For a ceiling-mounted or rain shower, measure to the showerhead when aligned parallel to the floor.
Guideline: Same as Building Code Re­quire­ment.
Building Code Re­quire­ment: Shower and Tub / Shower control valves must be one of the following:
  1. Pressure balanced,
  2. Thermostatic mixing, or
  3. Combination pressure balance/thermostatic mixing valve types. (IRC P2708.3)
  1. These requirements are intended to reduce the risk of scalding. If the cold water fails for any reason, the shower is prevented from continuing to pump out hot water by these valves that either shut the water off or rebalance the temperature.
  2. Some jurisdictions require these valves only on multi-family residences but regardless of your local code requirements, it is always a good idea to install one of these types of shower valves whenever a bathroom is remodeled. In our bathroom remodels, we always specify one of these types of shower valves. In our opinion, no conscientious bath remodeler will do anything else when remodeling a bathroom.
  3. It is almost impossible to buy shower control valves from a mainline manufacturer that are not either pressure balanced or thermostatic mixing but some inexpensive valves from generic suppliers of imported shower controls may not have these features, so look for one or the other in any shower or tub valve. If a licensed plumber installs the valve, it will almost certainly be one of the other but it never hurts to ask.
  1. What is the difference between the two types?
  2. The older, pressure balanced valve invented by Symmons Industries in 1939 senses differences in water pressure between the incoming cold and hot water, and keeps the pressure balanced. But, it does not sense fluctuations in temperature, so that if the hot water turns colder, it does not know to reduce the flow of the cold water to compensate.
  3. The newer thermostatic mixer technology senses variations in both pressure and temperature, and adjusts the water flow if either the water pressure or water temperature changes to keep the water within a few degrees of the set temperature. Electronically controlled mixers can even adjust the temperature of the water for each user.
  4. Of the two, the Thermostatic mixer is preferred but it is also usually the more expensive.
Guideline: Plan a seat within the shower that is 17"-19" above the shower floor and 15" deep.
Building Code Re­quire­ment: Shower seat must not infringe on the minimum interior size of the shower (900 square inches). (IRC P 2708.1)
  1. This guideline may give the impression that a shower seat is required. It is not but it is a good idea and should be considered when remodeling a bath shower. To meet plumbing code requirements, however, the shower must be large enough for a disk 30" in diameter to fit inside the shower walls and not touch the seat. See Guideline 9.
  2. One way to reduce the footprint of a shower seat so it will fit inside a smaller shower is to use a foldup seat. The seat must, however, still be outside the 30" minimum circle when folded up.
  3. This Guideline must be coordinated with Guideline 3 and Guideline 9.
Guideline: The wall area above a tub or shower pan should be covered in a waterproof material extending at least 3" above the showerhead rough-in.
Building Code Re­quire­ment: The wall area above a tub or shower pan must be covered in a waterproof material to a height of not less than 72" above the finished floor. (IPC 417.4.1, IRC R 307.2)
  1. In our bath remodels, we treat the code required 72" as the minimum height but build the enclosure to 3" or more above the shower rough-in as recommended by the guideline.
  2. The shower rough-in is nothing more complicated than the height at which the shower arm comes out of the wall.
  1. If a ceiling-mounted showerhead is used in a bath remodel, we generally build the enclosure to within 12" of the ceiling or to 84" in a bathroom with a standard 96" ceiling.
  2. The shower enclosure should not extend all the way to the ceiling on all four sides unless power ventilation is provided inside the enclosure. Otherwise, steam from the shower has no place to vent. Eventually, the constant moisture inside the shower enclosure will result in mold and mildew forming on the shower walls. Leave a space at least 6-12" between the top of the shower enclosure and the ceiling on at least one side for ventilation.

So the final rule is: The shower enclosure should be a minimum of 72" from the finished floor of the shower or 3" above the shower rough-in, whichever is higher, but at least one side of the enclosure should not be closer to the ceiling than 3" to allow for ventilation.

  1. Plan grab bars to facilitate access to and maneuvering within the tub and shower areas.
  2. Tub and shower walls should be prepared (reinforced) at time of construction to allow for installation of grab bars to support a static load of 300 lbs.
  1. Grab bars should be placed at least 33"-36" above the floor.
  2. Grab bars must be 1-1/4" to 1-1/2" in diameter and extend 1-1/2" from the wall.
Guideline Grab Bar Requirements
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code. The regulations under the Americans with Disabilities Act (ADA) contain requirements for grab bars in ADA-compliant housing.
  1. Whether or not grab bars are to be installed immediately, in any bath remodel, always include blocking in the walls for grab bars. Otherwise, installing them later may require removing part of the wall covering to gain access to install blocking.
  2. In any bath remodel, if planning for the possibility of limitations on mobility by any user, install grab bars in the bath and/or shower immediately, with blocking for the later addition of grab bars around the toilet.
  3. While ADA specifications for grab bars are not required in most single-family residences, they are excellent guidelines to follow in planning for and installing grab bars in any bathroom remodel.
Guideline: Same as Building Code Re­quire­ment.
Building Code Re­quire­ment:
  1. Glass used in tub or shower enclosures (i.e. tub or shower door) or partitions must be tempered or an approved equal and must be permanently marked as such. (IRC R 308.1)
  2. If the tub or shower surround has glass windows or walls, the glazing must be tempered glass or approved equal when the bottom edge of glazing is less than 60" above any standing or walking surface. (IRC R 308.4.5)
  3. Any glazing (i.e. windows or doors) whose bottom edge is less than 18" above the floor must be tempered glass or approved equivalent. (IRC R 308.4.7.2)
  1. This is a safety measure. Most building and safety codes require glass installed closer than 18" to the floor to be tempered because it is easy to break the glass by inadvertently kicking it. This applies to any room in the house, not just the bathroom. In planning a bathroom remodeling project where windows are involved, it is often easy to forget that glass over a tub or in a shower must be tempered.
  2. The 60" inch rule is also a safety measure to prevent you from putting your elbow through window glass while showering or bathing. Any glass at or above 60" is considered high enough that it is unlikely to be accidentally broken but any glass lower than 60" is at risk.
  3. Many older homes include bathroom windows that do not comply with these rules. Whether you have to plan for replacing non-conforming glass when remodeling a bathroom generally depends on the requirements of local code authorities.
  4. Where tempered glass is required, glass block may ordinarily be used instead but check with your local building code authority to make sure.
Guideline: Same as Building Code Re­quire­ment.
Building Code Re­quire­ment: Hinged shower doors shall open outward. (IRC P 2708.1)
  1. This is a safety requirement. If an individual loses consciousness or is injured in a shower, his or her body blocking an in-opening tempered glass door could prevent emergency medical personnel from getting in. As a consequence, even though it may result in water dripping on the floor of the bath, the door must open outward. An alternative, if there is enough space, is a sliding door.
  2. If a shower has two doors, can one door swing in? The national code is silent on this issue but the logical extension of the code is "yes". As long as one door is available for emergency ingress, the swing of the other door is irrelevant to the code.
  3. In planning a bathroom remodeling project, be sure to allow enough door swing space.See Guideline 2.
Guideline: Steps should not be placed outside a tub. If steps are used a grab bar/handrail is mandatory.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. This guideline refers to permanently installed steps, not temporary, removable steps.
  2. Steps in a bathroom where water can make them slippery are generally not a good idea. There are too many better ways to deal with getting into and out of a bathtub, including the many walk-in bathtub designs on the market.
  3. Certain bathroom styles, however, include bath steps as a design feature. For example, a Japanese Bath that includes a soaking or ofuru tub generally includes steps to get in and out of the tub.
  4. As a general rule, however, if at all possible, plan your bathroom remodeling project without bathtub steps of any kind.
Guideline: Slip-resistant surfaces should be specified for the general bath flooring, shower floors, and Tub/Shower bottoms.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. Ceramic tile flooring should have a coefficient of friction (COF) "wet" rating of 0.5 or more, higher is better. To learn how to choose slip resistant ceramic tile for your bathroom remodeling project, see "Porcelain vs. Ceramic Tile: Is There a Difference?".
  2. For an overview of the flooring choices available for bathrooms, see " Flooring Options for Kitchens and Baths".
Guideline: Same as Building Code Re­quire­ment.
Building Code Re­quire­ment:
  1. All equipment, including access panels, must be installed as per manufacturers' specifications. (IRC M 1307.1)
  2. All manufacturers' instructions must be available for installers and inspectors and left for homeowners. (IRC P 2720.1)
  1. All bathroom equipment and accessories installed during a bathroom remodel must be installed following the manufacturer's instructions. Most equipment made for use around water is tested and certified by various testing organizations to be safe only if installed in the way the manufacturer intends. If the manufacturer requires an access panel for equipment installed in a bathroom, the access panel must be built and must be the size and location specified in the manufacturer's installation instructions. This applies primarily to whirlpool tubs.
  2. Most local codes require that installation instructions for bath equipment and fixtures be delivered to the homeowner and available to the building or plumbing inspector.
Guideline: The distance from the centerline of a toilet and/or bidet to any bath fixture, wall, or another obstacle should be at least 18".
Building Code Re­quire­ment: A minimum distance of 15" is required from the centerline of a toilet and/or bidet to any bath fixture, wall or other obstacle. (IRC R 307.2, IRC P 2705.1.5,IPC 405.3.1)
  1. Your bathroom remodeling project should plan on the recommended 18” distance from the centerline of the toilet.
  2. However, if the toilet is already in place, and you do not plan to move the toilet, and if it meets the code minimum offset, then most of the time it's not worth the cost to move it.
  3. But, many toilets in old houses were set when no plumbing or building codes were in effect or the minimum code offset was less than 12”.
  4. Whether you will have to move it to meet the current code minimum is generally up to the local jurisdiction. In many localities, it is considered grandfathered and will be allowed to stary.
  5. If you do have to move it, consider whether your plans for the bathroom remodel will allow it to be relocated to provide the recommended 18" clearance. Most homeowners find this to be a more comfortable spacing.
  6. If you are planning a new toilet or are moving an old toilet, consider a wall-mounted toilet. Many homeowners find wall-mounted toilets Much easier to clean around, for obvious reasons. For more information, see Choosing The Perfect Toilet .
Guideline: The size of a separate toilet compartment should be at least 36" by 66" with a swing-out or pocket door.
Building Code Re­quire­ment: The minimum size for a separate toilet compartment is 30" by 60". (IPC 405.3.1)
  1. The Guideline implies that a toilet compartment must have a door. Actually, more toilet compartments are built without doors than with.
  2. An inswing door can be used if the width of the door is added to the depth of the compartment. For example, if the compartment has a 24" door, add 24" to the 66" length of the compartment. The new 90" depth accommodates the inswing of the door.
  3. This guideline also applies to a bidet compartment.
  4. If both a bidet and toilet or toilet and wall urinal are built into one compartment, the arrangement of fixtures within the compartment must conform to Guideline 20. This usually results in a minimum compartment width of between 62" and 65", depending on the width of the fixtures selected.
  5. If the compartment needs to be wheelchair accessible, the minimum width is 60".
Guideline: Provide adequate, accessible storage for toiletries, bath linens, grooming, and general bathroom supplies at their point of use.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.

Comment: Guidelines this vague border on the idiotic. Everyone knows you need "adequate" storage in a bathroom but what makes storage "adequate"? Since part of what we do in designing bathrooms includes adequate storage, we have some thoughts on the subject.

Any storage design must comply with the three Iron Rules of Storage:

The Iron Rules of Storage

  1.  Store each item where it is first used.
  2.  Size storage to the things being stored.
  3.  Store items in a single layer with no item hidden behind or underneath another.

It may not be possible to conform strictly to the rules in every case but the closer you can come, the more useful and satisfactory your storage will be. Fortunately, unlike a kitchen where storage can become a very complicated affair, bathroom storage is rather simple because there are many fewer things to store.

In most bathrooms the thing that must be stored are:

Towels and washcloths: There is no hard and fast rule for the number of towels or washcloths needed for each member of the family but there seems to be a consensus among designers that two of each per person is all that needs to be stored in the bathroom. Extra towels can be stored elsewhere. Towels are the bulkiest items stored in most baths but are also about the easiest items to store creatively. Colorful towels can add a great deal to the look of the room, so they can be stored on open shelves in plain sight. And, if you decide to change your look, towels are easy and relatively inexpensive to do over.

Rolled towels are more compact than folded towels and take up less storage room. And they make a great display. Show off your rolled towels by placing them upright inside a wicker basket, canvas bin, metal bucket, or something unconventional, such as a small antique trunk. Place the container on the floor or a shelf. If you have washcloths that match your towels, roll up each washcloth inside its matching towel.

A wine rack can make a great towel holder for rolled towels. Each roll can be set into its own nook, like a wine bottle. As towels are removed and used, the remaining towels won't be disturbed. There are even heavy-duty rolled towel holders used mostly by hotels but also look great in a domestic bathroom.

Toilet paper: At least one spare roll of toilet paper should be stored within easy reach of the toilet. Another four or so rolls should be nearby. One idea we like is to store the rolls in a woven basket set next to the toilet. It's convenient and adds an interesting texture to the room. Another good storage space is a narrow cabinet installed on the wall above the toilet.

First aid kit: According to the American Red Cross, every bathroom should contain a first-aid kit stored inside a handy cabinet. The kit should include assorted adhesive bandages, antibiotic ointment packs, an instant cold compress, hydrocortisone ointment packs, roller bandages, sterile gauze, an oral thermometer, and tweezers.

Cleaning supplies: Store all bathroom cleaning supplies, in a plastic bucket inside the vanity. Store the plunger and toilet brush near the cleaning supplies to keep them close at hand but out of sight. A vanity is usually terrible storage. It is dark, full of pipes, and too deep to reach to the back comfortably, or even to see what's in the back. But it works for cleaning supplies in a bucket or other container that can be easily removed.

Toiletries and Make-up: Toiletries and make-up should be stored neatly away and out of sight, not left on the edge of the bathtub or cluttering the sink area. Clutter makes a bathroom look smaller. The best storage solution we have found for makeup is a dedicated makeup drawer. Ours is melamine-coated on the inside to resist damage from spilled makeup and organized using an acrylic insert. If there is no room for a drawer in your vanity, then use a makeup box that can be stored under the sink.

Toiletries can be stored in a shallow, between-the-studs, wall cabinet. But, these require the wall to be reworked, and will not fit every bathroom. The best storage solution we have found that works in every bath is a toiletries box. Fetch the box before a bath then stick everything back in the box and store it away when you are done. If you can't hide the box in a cabinet, use a decorative wicker box instead and set it on a convenient shelf. If bathroom storage is severely limited, you can store the box in your bedroom.

The nice thing about toiletry boxes is that each user of the bathroom can have his or her own box – which eliminates arguments about who used the last of the shampoo. For kids, it's a great learning tool. If you forget to tell Mom you're low on shampoo and run out, then, unless you can bribe your sister into sharing, you get to go to school looking like Eddie Munster. It will probably happen only once.

Medicine: The one thing that should never be stored in the medicine cabinet is medicine. Heat and steam in a bathroom will damage many medications. Store all over-the-counter pain relievers, anti-allergy medications and prescription medicine in your bedroom, a hallway linen closet, or even the kitchen but never in the bathroom.

  1. Place a mirror above or near the lavatory at a height that takes the user's eye height into consideration.
  2. The toilet paper holder should be located 8" to 12" in front of the edge of the toilet bowl, centered at 26" above the floor.
  3. Additional accessories, such as towel holders, soap dishes, etc., should be conveniently located near all bath fixtures.
Building Code Re­quire­ment: No International Residential Code requirements. Always check your local codes for requirements not in the national code.
  1. Mirrors: There can be no hard and fast rules for setting a mirror. Mirrors come in various sizes and shapes, and so do users of the bathroom. The general rule we follow is to set the mirror so that the top of the glass portion is a few inches above the eye level of the tallest user. The mirror itself should be tall enough to permit all users to see from the top of his or her head to the top of the sink.
  2. Towel Bars and Rings: Towel bars should be set at a convenient height that looks good to you. For most bathrooms, 48" - 54" from the finished floor is usually about right. If the bath has a tile wainscot, you may want to adjust this height to avoid drilling through the tile. For children, a lower bar is often more convenient and encourages hanging up the towel. However, always leave enough space below the towel bar for a towel to hang freely without touching the floor or a surface below the bar. Generally, the absolute minimum height is 36" for towels, 18" for washcloths.
  3. Robe Hooks: Robe hooks should be set at 66" or higher, depending on the height of the user. Tall users might find that a higher hook is needed to keep the robe from touching the floor.
Guideline: All GFCI receptacles should be located at electrical appliance points of use.
Building Code Re­quire­ment:
  1. At least one GFCI protected receptacle must be installed within 36" of the outside edge of the lavatory. (IRC E 3801.6)
  2. All receptacles must be protected by Ground-fault-circuit-interrupters (GFCI). (IRC 3802.1)
  3. A receptacle shall not be installed within a shower or bathtub space. (IRC E 3902.10)
  4. Switches shall not be installed within wet locations in tub or shower spaces unless installed as part of the listed tub or shower assembly. (IRC E 3901.7)
  1. The general rule is that any outlet within 6 feet of a water source must be equipped with a Ground Fault Circuit Interrupter (GFCI). Every outlet in a bath is considered to be within 6 feet of a water source, and so must be a GFCI outlet.
  2. Neither an outlet nor an electrical switch can be located above a bathtub or closer than 36" to any edge of the bathtub. This helps prevent anyone in the tub from touching a switch or outlet and possibly getting electrocuted. Excluded from the prohibition against switches near the tub are the protected switches used to operate the jets in whirlpools, provided the switches are UL-listed for near-water use.
  3. Every bathroom must have at least one electrical outlet (in most places it must be at least a duplex outlet) located above or not more than 36" away from the edge of the vanity. If the sink is not located in a vanity, for example, a wall-hung or pedestal sink, then the outlet may not be more than 36" away from the edge of the sink.
  4. If your bathroom remodeling project violates any one of the code requirements, it is almost certainly going to have to be brought up to code. It's a safety issue.
Guideline: In addition to general lighting, task lighting should be provided for each functional area in the bathroom (i.e. grooming, showering).
Building Code Re­quire­ment:
  1. At least one wall-switch-controlled light must be provided. A switch must be placed at the entrance. (IRC E 3901.6, IRC E 3803.2)
  2. All light fixtures installed within tub and shower spaces should be marked "suitable for damp/wet locations". (IRC E 3903.8)
  3. Hanging fixtures cannot be located within a zone of 3' feet horizontally and 8' vertically from the top of the bathtub rim. (IRC E 3903.10)
  1. At least one electric light, controlled by a wall switch, must be provided in a bathroom. A pull-chain is no longer allowed. Other sections of the electrical code require that the switch be located near the entry door.
  2. The safest light over a tub or in a shower is a recessed light with a waterproof lens. If a surface-mounted ceiling lamp or hanging (pendant) lamp is used, then it must be 96" above the rim of the rub or 36" outside the edge of the tub. This rule seeks to prevent people from grabbing a handy light cord to steady themselves if they lose their balance in a tub or shower, and possibly pulling the live light fixture into the water. The light must also be high enough or outside the tub far enough so that a bather could not accidentally reach out and touch the light fixture while standing in water.
  3. Ceiling lights are usually wanted over the tub but since the ceiling in most baths is 96" from the floor, the light cannot possibly be installed 96" from the top of the bathtub rim, which is usually between 13" and 16" from the floor. The idea behind the rule is to keep people from grabbing onto electrical fixtures for balance if they start to slip. Falling is bad enough but electrocution combined with falling is even worse. Recessed lighting above the tub, if the light is enclosed with a water-resistant lens, is fine and will be approved by nearly all local inspectors.
Guideline: Plan a mechanical exhaust system, vented to the outside, for each enclosed area.
Building Code Re­quire­ment: Minimum ventilation for the bathroom is to be a window of at least 3 sq. ft. of which 50% is operable, or a mechanical ventilation system of at least 50 cubic feet per minute (cfm) ducted to the outside. (IRC R 303.3, IRC M 1506.3)
: Using a small window for bathroom ventilation is obsolete, and has been since whole-house heating and cooling virtually eliminated opening windows. Windows never did a particularly good job of ventilating a bathroom anyway. Even if you plan a bathroom window, also plan for adequate mechanical ventilation.
HVI Recommentations

The Heating Ventilation Institute (HVI) HVI is an industry association of heating and air conditioning product manufacturers that, among other things, tests and certifies ventilation products and publishes consumer guides on ventilation issues. These are the HVI recommendations for venting bathrooms:

  1. Small Bathrooms: HVI recommends that in small bathrooms, up to 100 square feet of floor space, the exhaust fan be sized to provide a ventilation rate of 1 cubic foot per minute ( cfm) for each square foot of floor (about eight air changes per hour). This usually results in a ventilation requirement of less than 50 cfm, so the code minimum fan size must be used.
    Example 1: The bathroom is 5' x 9' (with 8' ceilings). Multiply 5x9 = bathroom area of 45 sq. ft. At 1 cfm per square foot, the minimum recommendation is a fan rated at 45 cfm. This is less than the code minimum 50 cfm, which must be used.
  2. Medium and Large Bathrooms: For bathrooms larger than 100 square feet in area, HVI recommends a ventilation rate based on the number and type of fixtures present, according to the following table:
    Toilet: 50 cfm Shower: 50 cfm
    Bathtub: 50 cfm Tub/Shower Combo: 50 cfm
    Whirlpool Tub: 100 cfm Bidet: 50 cfm

    To calculate the minimum fan rating, add the cfm for each fixture in the room to arrive at a total cfm.

    Example 2: The bathroom is 20'x12'. There is a tub, a separate shower enclosure, and a toilet.
    Toilet    50 cfm
    Shower    50 cfm
    Bathtub    50 cfm
    Minimum Fan Rating    150 cfm
  3. Toilet Compartment: If a toilet is in an enclosed stall with a door, then the toilet enclosure is considered by most code authorities to be a separate room. Likewise, if a shower is enclosed right to the ceiling, it will be considered a separate room. These guidelines recommend a separate mechanical exhaust system for "each enclosure", which means a fully enclosed toilet or shower must have its own exhaust fan separate from that of the rest of the bathroom. In most localities, this is also the building code requirement. A steam shower always needs its own ventilation. Strictly follow the manufacturer's recommendation for venting a steam shower. Otherwise, you will have mold growing in places you would not think mold could grow.
  4. Example 3: The bathroom is 15'x15'. There is a tub, a separate, fully enclosed, shower and a fully enclosed toilet in a stall with a door. A fully enclosed toilet or fully enclosed shower should have their own exhaust fans rated at 50 cfm each. The bathroom fan will exhaust only the bathtub and should also be rated at the code minimum 50 cfm.
  5. How Long to Ventilate: When house air is exhausted to the outside, heat goes with it, meaning that your furnace has to work harder to make up for the lost heat. You want to exhaust moist air to reduce the risk of mold and mildew but once the moist air is gone, you want to stop ventilating. HVI recommends that the fan be left on for a minimum of 20 minutes after use of the bathroom. A timer is a good solution, allowing the fan to turn off automatically at the proper time
  6. There are also fans on the market now that sense the level of humidity in the air and automatically turn on when it is too high, and turn off when it is back to normal. Unfortunately, there is as yet no fan that senses offensive odors, so a manual switch is still necessary.
Guideline: A supplemental heat source, i.e., heat lamp, toe kick heater, or floor heat, should be considered.
Building Code Re­quire­ment: All bathrooms should have an appropriate heat source to maintain a minimum room temperature of 68° Fahrenheit (20° Celsius).
  1. Generally, a bathroom should be 10° warmer than the rest of the house when someone is bathing or showering. Normal warm room air on wet skin feels cold.
  2. Whatever the supplemental heating solution, it should not involve blowing air. Moving air on wet skin feels cold no matter how warm it is.
  3. Underfloor electric radiant heating, heat lamps, and wall-mounted radiant heating should be considered. An inexpensive panel heater like the one shown or a baseboard heating unit are inexpensive additions.
  4. Supplemental heating should include a separate room thermostat and some form of automatic shutoff or timer to ensure the supplemental heat is not left on once the need for it has passed. Otherwise, a lot of electricity is wasted.

Rev. 04/21/22