Terminology

• Water closet: plumbing code term for a toilet
• Gravity tank / pressure-assist tank: residential and light commercial flush types
• Flushometer valve: tankless commercial valve on a larger supply line
• Wall-hung / floor-mounted: carrier-supported or floor-flanged fixtures
• Elongated bowl / open-front seat: required for public and employee toilets
• Dual flush: two flush volumes
• HET / WaterSense: high-efficiency, lower-flush fixtures
• Waterless (nonwater-supplied) urinal: uses a trap cartridge or seal liquid
• Carrier: concealed steel frame supporting wall-hung fixtures

Standards

Ratings

• Maximum 1.6 gallons per flush for water closets and 1.0 gallon per flush for urinals
• Fixtures centered at least 15 in. from side walls or partitions, at least 30 in. center to center, with at least 21 in. clear in front
• Compartments at least 30 in. wide by 60 in. deep for floor-mounted and 56 in. deep for wall-hung water closets
• Urinal partitions at least 30 in. apart, extending at least 18 in. from the wall
• Urinals may replace up to 67 percent of required water closets in assembly and educational occupancies, and up to 50 percent elsewhere
• Accessible water closets centered 16 to 18 in. from the side wall, seat 17 to 19 in. high, with 60 in. wide by 56 in. deep clearance
• Wheelchair accessible compartments 60 in. wide, 56 in. deep for wall-hung and 59 in. deep for floor-mounted water closets; ambulatory compartments 35 to 37 in. wide
• Accessible urinal rims 17 in. maximum above the floor, at least 13-1/2 in. deep

Test standards

• ASME A112.19.2/CSA B45.1: ceramic plumbing fixtures
• ASME A112.19.14: dual-flush devices
• ASME A112.19.19: urinals
• EPA WaterSense: high-efficiency fixtures

Components

• Fixture: vitreous china bowl or urinal
• Flush device: tank, flushometer valve, or sensor operator
• Seat: open-front for public use
• Carrier and supports: for wall-hung fixtures
• Partitions: toilet compartments and urinal screens
• Grab bars and accessories

Detailing

• Lay out restrooms from fixture counts, clearances, and accessible stalls together
• Use wall-hung fixtures and carriers for cleaning; provide chase space behind
• Coordinate flushometer supply sizes and pressure with domestic water design
• Provide blocking for grab bars and partitions
• Locate flush controls on the open side of accessible water closets

Uses

Specific uses

• Public and employee restrooms
• Dwelling unit bathrooms
• Schools and assembly venues with high peak use
• Healthcare with bedpan washers and specialty bowls

Pros and cons

Pros

• Low-flow fixtures cut water use
• Wall-hung fixtures ease floor cleaning
• Urinals reduce water closet counts and space

Cons

• Flushometers need adequate supply pressure
• Waterless urinals need regular cartridge maintenance
• Carriers and chases add wall depth

Manufacturing and cost

Construction

• Fixtures cast from vitreous china, glazed, and kiln fired; carriers and rough-in installed with piping; fixtures set after finishes

Main manufacturers and suppliers

• Kohler
• American Standard
• TOTO
• Sloan (flushometers)
• Zurn

Trade associations: Plumbing Manufacturers International and IAPMO.

Sources

• UpCodes: 2024 IPC Chapter 4 fixtures, faucets, and fixture fittings (GSA adoption without amendments), https://up.codes/viewer/general-services-administration/ipc-2024/chapter/4/fixtures-faucets-and-fixture-fittings
• UpCodes: 2024 IPC Chapter 6 water supply and distribution (maximum flow rates), https://up.codes/viewer/general-services-administration/ipc-2024/chapter/6/water-supply-and-distribution
• Corada: 2010 ADA Standards Section 604 water closets and toilet compartments, https://www.corada.com/documents/2010ADAStandards/604
• Corada: 2010 ADA Standards Section 605 urinals, https://www.corada.com/documents/2010ADAStandards/605
• Wikimedia Commons: Diagram of a jet-siphonic WC bowl.svg, by SouthHamsian (CC BY-SA 4.0), https://commons.wikimedia.org/wiki/File:Diagram_of_a_jet-siphonic_WC_bowl.svg