)- On many projects, the interior designer allocates the space for the public restrooms and places the fixtures. Toilet rooms in public facilities are often allotted minimal space and have to be designed with ingenuity to accommodate the required number of fixtures. The location of public restrooms should be central without being a focal point of your design.
Usually a licensed engineer designs the building's plumbing system. On small projects like adding a break room or a small toilet facility, an engineer may not be involved, and a licensed contractor will work directly off the interior designer's drawings or supply their own plumbing drawings. The design of public restrooms also involves coordination with the building's mechanical system. The type of air distribution system, ceiling height, location of supply diffusers and return grills on ceilings, walls, or floor, and the number and locations of thermostats and heating, ventilating, and air-conditioning (HVAC) zones influence the interior design.
Interior designers must be aware of the specific numbers and types of plumbing fixtures required by codes for public buildings. The model building codes that cover plumbing include the Building Officials Code Administrators International's (BOCA's) National Plumbing Code (NPC), the Standard National Plumbing Code (SPC), and the Uniform National Plumbing Code (UPC). These codes are geared toward plumbing engineers and professional plumbing contractors. The chapter in the codes dealing with plumbing fixtures is useful to the interior designer in determining the minimum number and types of fixtures required for particular occupancy classifications. There may be more than one code applying to a particular project, and sometimes the codes don't agree with each other.
The plumbing codes also include privacy and finish requirements and minimum clearances. The entrances to public restrooms must strike a balance between accessibility and privacy, so that they are easy to find and enter, but preserve the privacy of users. Frequently men's and women's toilet rooms are located next to each other, with both entries visible but visually separate. This avoids splitting families up across a public space, is convenient for those waiting, makes finding the restrooms easier, and saves plumbing costs. The area just outside the restroom should be designed to allow people to wait for their friends, but should avoid closed-off or dark areas where troublemakers could loiter.
Restrooms with multiple water closets must have toilet stalls made of impervious materials, with minimum clearance dimensions and privacy locks. Urinals have partial screens but do not require doors. Generally, lavatories are located closer to the door than toilets, in part to keep the most private functions out of the line of sight, and also to encourage washing after toilet use. Both men's and women's rooms should have baby-changing areas where appropriate. Some facilities, such as health clubs, have family changing and toilet rooms, small rooms designed for use by a parent or two and their children. This eliminates the dilemma of the dad with a four-year-old daughter, or the mom with a young son, especially when changing clothes.
The Americans with Disabilities Act Accessibility Guidelines (ADAAG) and the American National Standards Institute (ANSI) accessibility standards list access requirements, as do model codes. These requirements include minimal clearances, location requirements, and controls that are easy to use. Generally, washroom accessories must be mounted so that the part that the user operates is between 97 and 122 cm (38-48 in.) from the floor. The bottom of the reflective surface of a mirror must not be more than 102 cm (40 in.) above the floor. Grab bars must be 84 to 91 cm (33-36 in.) above the floor. Wheelchair access (Figs. 14-1, 14-2, 14-3) generally requires a 152-cm (5-ft) diameter turn circle. The turn circle should be drawn on the floor plan to show compliance. When this is not possible, a T-shaped space is usually permitted. Special requirements pertain to toilet rooms serving children aged three to twelve. States may have different or additional requirements, so be sure to check for the latest applicable accessibility codes.
The conventional height of a toilet seat is 38 cm (15 in.). The recommended height for people with disabilities is 43 to 48 cm (17-19 in.). Doors on accessible stalls should generally swing out, not in, with specific amounts of room on the push and pull sides of doors.
The ADA requires that all restrooms, even if only partially accessible, be fully accessible to the public, with adequate door width and turning space for a wheelchair.
Minimum 1220 mm
Figure 14-1 Accessible toilet stall: front approach.
A single toilet facility is usually required to be accessible or at least adaptable to use by a person with disabilities. A door is not allowed to impinge on the fixture clearance space, but can swing into a turn circle. The ADA also regulates accessories such as mirrors, medicine cabinets, controls, dispensers, receptacles, disposal units, air hand dryers, and vending machines. The heights of light switches and electrical receptacles are also specified. Where nonaccessible toilets already exist, it may be possible to add a single accessible unisex toilet rather than one per sex.
The ADA requires a minimum of one lavatory per floor to be accessible, but it is not usually difficult to make them all usable by everyone. An accessible lavatory has specific amounts of clear floor space leading to it, space underneath for knees and toes, covered hot water and drain pipes, and lever or automatic faucets. The ADA lists requirements for clearance and height.
The number of required plumbing fixtures must be
Clear Floor Space
Clear Floor Space
Minimum 1220 mm
Figure 14-2 Accessible toilet stall: side approach.
Clear Floor Space
Minimum 1525 mm oo
Accessible toilet stall: shorter stall with wider calculated in new construction, in building additions, and when an occupancy classification changes. The number of required fixtures is based on the total number of occupants within the building or space. Typically, each floor requires a minimum of one toilet or rest-room. Some tenant facilities may require their own toilet facilities, which can then be deducted from the total building requirements. The fixtures that may be required include water closets and lavatories, urinals, drinking fountains, bathtubs, showers, and washing machines. The NPC and UPC base the number of occupants on the occupant load used by the building code. The SPC requires a separate calculation. Code requirements are minimal, and buildings where many people may want to use the restrooms at the same time may want to install additional facilities.
Urinals may be required in some male restrooms depending upon the occupancy. Schools, restaurants, lounges, transportation terminals, auditoriums, theaters, and churches may have specific requirements. Facilities that tend to have heavy male restroom use, such as bars, often install additional urinals beyond the fixtures required by code.
Some occupancies with limited square footage and minimal numbers of occupants, such as small offices, retail stores, restaurants, laundries, and beauty shops, are permitted to have one facility with a single water closet and lavatory for both men and women. These facilities must be unisex and fully accessible. Adjustments may be made for facilities used predominantly by one sex if the owner can provide satisfactory data to the code officials.
In larger buildings, fixtures may be grouped together on a floor if maximum travel distances are within the limits established by code. Employee facilities can be either separate or included in the public customer facilities. It is common to share employee and public facilities in nightclubs, places of public assembly, and mercantile buildings.
Wherever there are water closets, there must be lavatories. However, lavatories are not required at the same ratio as toilets. Large restrooms usually have more water closets than lavatories.
Was this article helpful?