This article is excerpted from Bath Planning, one of nine books in the NKBA’s Professional Resource Library.

A walkway of 48 inches allows 18 inches for a person using a fixture and 30 inches for a person to walk behind them.

In partnership with the National Kitchen & Bath Association, Supply House Times continues its year-long kitchen and bath educational series with a review of recommendations and requirements for the placement of major bath fixtures. This article, excerpted from Bath Planning, one of nine books in the NKBA’s Professional Resource Library, explains planning considerations such as floor space and clearances for tubs, showers, toilets and lavatories, and also includes a few key NKBA Bathroom Planning Guidelines.

It takes about 18 inches of floor space for a person to stand to wash their hands, and about 20 inches for a person to bend to wash their face.

Wherever a tub is placed, it is recommended that at least a 30-inch clear space be planned along the side of it. If dressing is to occur in front of the tub, more space is needed. A 42-inch to 48-inch dressing circle will allow room for a user to dry off and put on undergarments.

Building codes allow a minimum of 21 inches in front of the tub, but this will be tight for many users. If a parent is helping bathe children, or a caregiver is assisting someone with a bath, extra floor space will be needed to accommodate them as well as the user.

If the bather will be transferring to the tub from a mobility aid or wheelchair, then 30 inches would be a minimum requirement, with more space preferred. When planning for a free-standing tub, consider which side(s) of the tub will be used for entering, exiting and passage, and allow the proper clearances.

Grab bars placed in the tub will give users something to hold onto as they enter and exit, thus alleviating some balance problems. NKBA recommends grab bars at the tub and shower to assist with this transfer. There are many decorative and attractive grab bars available to match other trim and accessories in the bathroom. It is critical that they be installed so they support at least 250 pounds. Some clients may need more support.

The wall behind the tub and shower should be reinforced to support the grab bar. The placement of the bar should be planned where it best fits the user.

Besides rails placed at the back and ends of the tub, a vertical bar at the front, and one on the back wall at a diagonal, are often helpful. Standard towel bars and soap dishes will not support someone in a fall and can be dangerous, since they protrude.

Faucet controls should be accessible to the user before entering the tub. In an enclosed tub or tub/shower combination, the controls may be placed on the wall at 33 inches above the finished floor. In general, off-setting the controls toward the room improves access by reducing bending and stretching.

Placing controls within 6 inches of the front wall makes them more accessible. For a free-standing tub, or one placed in a platform, controls should be on the front side. The user should not have to lean across the tub to turn on the water and check temperature. Place the faucet and controls so they do not conflict with the transfer area.

Besides faucet placement, the type and design should be considered. A faucet with a hand spray and 60-inch hose allows a caregiver to assist with bathing. Controls should be easy to grasp and manipulate. Any design other than smooth round knobs improves function. A single control is easier to use than separate hot and cold controls.

A clear space of 30 inches in front of the lavatory is recommended for comfortable use of the fixture, according to NKBA Bathroom Planning Guidelines. A minimum clearance is 21 inches.



At least 30 inches of clearance is recommended in front of the shower for comfortable access. Building codes require 24 inches of clear space in front of the shower, but this will be a limited area. A dressing circle of 42 inches to 48 inches might be needed for drying off and changing into clothing. If the bather will be transferring from a wheelchair or other mobility aid to the shower, a 36-inch x 48-inch space is a minimum requirement, with more space preferred.

Most prefabricated showers come in standard sizes from 32 inches to 48 inches square.

The recommended interior shower size for one person is at least 36 inches x 36 inches. This allows one person to comfortably stand in the shower with arms raised to wash their hair. Building codes state that the minimum interior shower size is 30 inches x 30 inches, but this is a tight space for most adults.

Check angled showers to make sure a 30-inch disc will fit into the shower floor. This will meet minimum code requirements. A larger disc area should be specified when user needs require more space. A 36-inch x 36-inch size is acceptable for a transfer shower to be used by a person transferring from a mobility aid.

A roll-in shower used by a person with a bathing wheelchair should be at least 36 inches x 60 inches. Access standards suggest a 30-inch minimum width, but 36 inches to 42 inches makes it easier to contain the water in the shower.

For a person to move out of the shower spray inside the shower, a 42-inch x 36-inch shower should be considered. Larger prefabricated showers are available, and custom showers can be designed to meet the needs of the user. (Check that any prefabricated shower will fit through the bathroom door.) In a shower at least 60 inches deep, it is possible to control the spray within the shower. In a two-person shower, make sure there is room for both people.

Grab bars are recommended for the back and sides of the shower. As in the bathtub, the grab bars in the shower should be able to support at least 250 pounds. When possible, it is better to place reinforcement throughout the shower walls so clients can add support when and where they will use them.

A vertical bar at the shower entrance provides a helpful support when getting in and out. The surface and design of all grab bars should reduce the risk of a hand slipping on the bar.

Placing the center of a single lavatory 20 inches from a wall or tall object provides about 6 inches of counter space and is recommended by NKBA in its Bathroom Planning Guidelines. The minimum distance is 15 inches on center. If a wall-hung or pedestal lavatory is used, make sure there is at least 4 inches from the edge of the lavatory to the wall.


Shower Seat

A seat is very helpful to many people as they shower. A person whose stamina is reduced due to age, pregnancy, injury, or too much physical activity, may not have the energy to stand throughout the shower. A woman may find a seated position the best for shaving her legs. A larger two-person shower usually has room for a bench. A seat or bench in the shower provides an opportunity to relax, assistance to people with limited strength or balance, and help with transfer.

NKBA recommends that a shower seat be planned. It should be 17 inches to 19 inches high from the finished shower floor and at least 15 inches deep, finished. The bench should not interfere with the recommended minimum shower size of 36 inches x 36 inches of floor area, although codes will allow the minimum 30-inch x 30-inch size to be maintained. Just as in the tub area, when less than 15 inches is available, a narrower bench can benefit some users. Attention must be given to the user’s size and weight so the seat will support the intended use.


Shower Controls

The showerhead should be placed so it directs water toward the body, not the face or hair. A fixed showerhead, roughed in at 72 inches to 78 inches off the floor, is typical in many showers and tub/shower combinations. Plan the shower rough-in so that the bottom of the showerhead will be 72 inches off the finished floor or at a height appropriate to the user.

A showerhead on an adjustable bar, or a handheld showerhead, offers flexibility in a shower used by persons of different heights, or for different activities. When the adjustable height shower/hand spray is used, its lowest position should always be within the universal reach range (15 inches to 48 inches above finished floor).

The most convenient way for a plumber to install the shower control valves is to line them up under the showerhead. However, this is not most convenient for the user. Being able to reach the controls while standing outside of the shower spray is ideal. NKBA recommends that the controls be placed out of the water spray and between 38 inches to 48 inches above the floor. An accessible location is 6 inches from the outside of the fixture.

Codes require that shower control valves must be either pressure balanced, have thermostatic mixing, or have a combination of both, to prevent scalding due to changes in water pressure. Hot and cold water controls should be easily identified with red and blue indicators. Consider a lever or loop handle control for ease of use. A handheld shower may be used in place of, or in addition to, the fixed showerhead to offer the user flexibility. This may be especially nice if the user will sit to shower.

If two people will be using the shower at the same time, there should be at least two showerheads, and each should be controlled separately. Design of the shower should take into account the number of body sprays, jets, control valves and diverters needed.


Shower Surround

The surround of a shower or tub/shower combination should be of a waterproof material and extend a minimum of three inches above the showerhead rough-in. A typical rough-in is 72 inches to 78 inches. Codes require the waterproof wall materials extend at least 72 inches above the finished floor.

Prefabricated shower surrounds may be one piece, or divided into multiple pieces assembled onsite. Check the size of the room entry to make sure an installer can get a prefabricated unit into the room.

When planning a double lavatory configuration, NKBA Guidelines recommend that the center of the fixtures be 36 inches apart. The minimum distance is 30 inches. If two pedestal or wall-hung fixtures are planned, make sure the edges are at least 4 inches apart.


Toilet Clearance

People using the toilet will need to stand, turn, sit, remove and replace parts of their clothing, and use nearby supplies like toilet paper. At least 30 inches of clear space is recommended in front of the toilet to allow for these activities, and perhaps more will be needed for larger people or persons needing assistance. Building codes allow this space to be reduced to 21 inches. This may allow leg room to sit on the toilet, but managing clothes may require moving to an area of the bathroom with more floor space.

For a person approaching the toilet with a mobility aid, or transferring from a wheelchair, 30 inches in front of the toilet is a minimum clear space, but more is better. For a person approaching and transferring from the side, plan a minimum 30 inches clear floor space to the side of the toilet. Wall-hung toilets improve the clear floor space, making it easier to transfer onto the toilet and to maintain the floor around it.

Some users may need grab bars, so plan reinforcement around the toilet area so that they can be installed. Grab bars should be placed according to the user’s requirements, including their method of transfer. NKBA’s Access Standards suggest that the grab bars be placed behind the toilet and on the wall beside it.


Toilet Placement

The toilet can be in several places within the bathroom and may be within its own separate area or compartment if space allows. There should be clearances on both sides of the toilet to allow the user to be able to sit comfortably and to move the upper part of the body without bumping into a wall or counter.

Placing the toilet at least 18 inches on center from the nearest wall or obstacle is the recommended distance. Building codes will typically allow the toilet to be placed 15 inches on center. Remember that this should be a clear space. Placing another obstacle in the space, such as a grab bar, towel bar or toilet paper holder, will interfere with the clearance.


Toilet Compartment

Placing a toilet in a separate compartment can be accommodated by following the previously recommended clearances. A 36-inch x 66-inch space measured from the inside wall will accommodate the recommended clearances. A 30-inch x 60-inch space will comply with building codes.

It is important that the toilet paper dispenser be convenient to the user. The best location is on a wall or partition to the side, and slightly to the front, of the toilet. This allows the user to reach the paper while seated. Locations behind the toilet or across from the toilet will be difficult to reach without bending or stretching. The recommended location for the toilet paper is 8 inches to 12 inches in front of the toilet, centered 26 inches off the floor. The recommended clearances for the bidet are the same as for the toilet.

A shower at least 36 inches x 42 inches allows one person to step out of the water spray.


Lavatory Floor Clearance

Anthropometric data indicates that about 18 inches of floor space is required for a user to stand and face the lavatory. It is also important to be able to bend at a comfortable angle when washing hands or face.

While 18 inches may allow some people to stand, it does not account for the movement of the standing user that might take place at the lavatory. NKBA recommends 30 inches of clearance in front of the lavatory for a more comfortable space. This would even allow a person to place a seat at the lavatory. Building codes will permit 21 inches of floor clearance in front of the lavatory, but this will be very tight.

However, 30 inches does not provide adequate clearance for two people to use the space and move around each other, since the average shoulder width is 24 inches. A floor space in front of the lavatory of 48 inches will accommodate two users comfortably. A minimum 30-inch x 48-inch space should be allowed in front of the lavatory for a user with an assistive device.

The toilet paper holder should be 8 inches to 12 inches in front of the toilet and 26 inches off the floor, according to NKBA Bathroom Planning Guidelines.


Side Clearance

Body size affects how much room a person needs on either side of the lavatory. To complete typical grooming activities, a person needs to be able to raise hands and elbows. The recommended distance from the center of the lavatory to a wall or tall obstruction is 20 inches.

This provides about 6 inches of clear counter space from the edge of the average lavatory to the wall or obstruction, but may not be adequate. Consider the breadth of the user and items placed on the counter to determine if more counter area is needed.

The minimum distance is 15 inches from centerline of the lavatory to the wall, according to building code, providing only about 2 inches from the edge of the average lavatory to the wall or obstruction. If a wall-hung or pedestal sink is specified, allow 4 inches between the edge of the lavatory to the wall.

If two lavatories are being planned beside each other, 36 inches between the centerlines of the lavatories is recommended. The code requirement for the centerline distance is 30 inches. The codes require a 4-inch clearance between the edges of two freestanding or wall-hung lavatories.

The recommended clearance in front of a tub is 30 inches, according to NKBA Bathroom Planning Guidelines. A minimum distance would be 21 inches.


Lavatory Heigh

Traditionally, the lavatory has been 30 inches to 32 inches high, although recently higher cabinets have become available. Work surfaces in the bath, like those in the kitchen, should be about 3 inches below the users’ elbow height. Subtracting 3 inches from the average female’s elbow would place the comfortable height at 36 inches.

A recommended range of heights for men is 37 inches to 43 inches. For women, it is 32 inches to 36 inches; and for children, 26 inches to 32 inches. When a knee space is planned for a seated user at a vanity, the height of the lavatory may range from 28 inches to 34 inches.

The recommended range of lavatory heights in the NKBA Bathroom Planning Guidelines reflects adult users and is 32 inches to 43 inches. Remember to plan the lavatory height so that the rim is 3 inches below the elbow of the user.

If two users will use the same lavatory, a compromise will have to be made and discussions with the client will help determine which height is most comfortable. Two lavatories of different heights may be the best solution.

There are many styles of lavatories, and the selection will impact how lavatory height is planned. Wall-mounted lavatories and those placed on wall-mounted counters offer flexibility in the height of the fixture. Pedestal sinks, wall-hung sinks and console-style vanities also improve the clear floor space in front of, and under, the fixture.

NKBA Bathroom Planning Guidelines recommend a shower at least 36 inches x 36 inches. The minimum sized shower is 30 inches x 30 inches.

When using a pedestal sink, the designer will be limited by the height of the specified product. The pedestal may need to be placed on a platform to reach the appropriate height for the user. Finish the platform at the baseboard height, and in the same material as the floor, so that it blends.

Several styles of vanity lavatories can be placed in a counter: integral, self-rimming, under-mounted and rimmed. A vessel lavatory can be set on or cut into the counter. In all of these applications, it is important to estimate the actual height of the lavatory rim. A vessel lavatory will sit several inches above the counter, so add the height of the lavatory to the cabinet and counter heights, to get the finished height.

Because vanity bases are often low (30 inches to 32 inches), a cabinet or console may need to be adjusted to place the lavatory at the appropriate height. Although a 34 1/2-inch cabinet with 1 1/2-inch countertop might be the appropriate height, specifying a kitchen cabinet might be out of proportion to the specified lavatory. Standard kitchen cabinets are 24-inches deep, but many lavatories have been designed to fit in the typical 21-inch deep vanity cabinet.

To get the vanity cabinet at an appropriate height, specify a higher cabinet, or raise a standard cabinet by placing it on a deeper toe kick or mounting it on the wall and not using a toe kick. If the toe kick is raised, consider raising the baseboard dimension throughout the room for a clean line at the room base.

If the cabinet is raised, it creates a “floating” effect, which can be enhanced by decorative lighting. Plus, it improves access by increasing clear floor space. The same flooring material used throughout the bathroom should be used beneath the cabinet.

Shower controls should be placed 38 inches to 48 inches off the floor, according to NKBA Bathroom Planning Guidelines. Offsetting the controls toward the front of the shower will make them accessible both inside and outside the water spray.


Seated Vanity

People who wish to sit while using the lavatory can benefit from a knee space at the lavatory or at a vanity. If the opening is for a person in a wheelchair, the minimum code-related dimensions for the opening under the counter are 30 inches wide by 27 inches high by 19 inches deep. A 36-inch wide knee space is recommended, since the opening can then be used as part of a T-turn. The exact counter height for a specific client will be determined by the height of the client’s knees and sometimes the wheelchair arm. When creating a knee space, support for the suspended counter should be planned.

This article is excerpted from Bath Planning one of the nine books in the NKBA’s Professional Resource Library. Written by recognized industry experts and thoroughly reviewed by top technical editors and peers, the volumes cover design, products, residential construction, mechanical systems, business practices, drawing, project management and more. The books, as well as the Kitchen and Bathroom Planning Guidelines booklet, are available only through the Association, at or call (800) THE-NKBA.