# Water Outlet: Building Code Definition

> How the IRC 2009, IPC 2009 define water outlet, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/water-outlet/
- Last updated: 2026-09-07
- Data source: Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IRC 2009, IPC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 4 (counted across the codes hosted here) |
| Wording identical across codes | No (compare before citing one code's wording under another) |

## Direct answer

Water outlet is a defined term in the International Residential Code (IRC) 2009, in Definitions. The code's own words are: “A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of the supply system.” The IPC 2009 defines the same term with different wording, so the controlling text depends on which code governs the question in front of you — the comparison below sets the versions side by side. The term is used in 4 chapters of this corpus, most often in Water Supply and Distribution (IPC 2009), Water Supply and Distribution (IRC 2009), Definitions (IPC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted.

*Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Water Outlet** — IRC 2009, Definitions:

> A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of the supply system.

![Labeled code-term definition diagram: Water Outlet: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/water-outlet/diagram-1344.webp)

*How the IRC 2009, IPC 2009 define water outlet, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

Two of the I-Codes in this corpus define **Water Outlet**, and the wording is not identical — read the version that governs your question.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IRC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of the supply system. |
| IPC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/definitions.md) | A discharge opening through which water is supplied to a fixture, into the atmosphere (except into an open tank that is part of the water supply system), to a boiler or heating system, or to any devices or equipment requiring water to operate but which are not part of the plumbing system. |

## Where water outlet is used in the code

The term appears in 4 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/water-supply-and-distribution.md) | IPC 2009 | 7 |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/water-supply-and-distribution.md) | IRC 2009 | 5 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/definitions.md) | IPC 2009 | 3 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | IRC 2009 | 3 |

### The term in use

How the code actually writes about water outlet, quoted from the 2009 text hosted here:

> The minimum required air gap shall be measured vertically from the lowest end of a potable water outlet to the flood level rim of the fixture or receptacle into which such potable water outlet discharges.

— [IPC 2009 §608.13.1](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/water-supply-and-distribution.md)


## The terms water outlet is built out of

The definition above leans on 5 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what water outlet covers:

- **[Water Supply System](https://harth.build/resources/glossary/water-supply-system.md)** — IPC 2009: The water service pipe, water distribution pipes, and the necessary connecting pipes, fittings, control valves and all appurtenances in or adjacent to the structure or premises.
- **[Plumbing Appliance](https://harth.build/resources/glossary/plumbing-appliance.md)** — IRC 2009: An energized household appliance with plumbing connections, such as a dishwasher, food-waste grinder, clothes washer or water heater.
- **[Plumbing Fixture](https://harth.build/resources/glossary/plumbing-fixture.md)** — IRC 2009: A receptor or device that requires both a water-supply connection and a discharge to the drainage system, such as water closets, lavatories, bathtubs and sinks.
- **[Plumbing System](https://harth.build/resources/glossary/plumbing-system.md)** — IRC 2009: Includes the water supply and distribution pipes, plumbing fixtures, supports and appurtenances; soil, waste and vent pipes; sanitary drains and building sewers to an approved point of disposal.
- **[Potable Water](https://harth.build/resources/glossary/potable-water.md)** — IRC 2009: Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming in bacteriological and chemical quality to the requirements of the public health authority havingjurisdiction.

## Water Outlet: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IRC | Definitions | |
| Read the definition in the adopted IPC | Definitions | |
| Re-check the requirement that uses it | Water Supply and Distribution (IPC 2009) | |
| Re-check the requirement that uses it | Water Supply and Distribution (IRC 2009) | |
| Re-check the requirement that uses it | Definitions (IPC 2009) | |
| Re-check the requirement that uses it | Definitions (IRC 2009) | |
| Confirm the dependent definition | Water Supply System | |
| Confirm the dependent definition | Plumbing Appliance | |
| Confirm the dependent definition | Plumbing Fixture | |
| Local amendment to any of the above | Jurisdiction's amendment list | |

**A research aid, not a code determination.** The authority having jurisdiction decides which edition and which amendments apply.

## Where can you explore related guidance?

- [Explore all glossary guidance](https://harth.build/resources/glossary.md)
- [Water Supply System: Building Code Definition](https://harth.build/resources/glossary/water-supply-system.md)
- [Plumbing Appliance: Building Code Definition](https://harth.build/resources/glossary/plumbing-appliance.md)
- [Plumbing Fixture: Building Code Definition](https://harth.build/resources/glossary/plumbing-fixture.md)
- [Plumbing System: Building Code Definition](https://harth.build/resources/glossary/plumbing-system.md)

## Sources and method

Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of water outlet?

The International Residential Code (IRC) 2009 defines it in Definitions as: “A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of the supply system.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.

### Which parts of the code depend on water outlet?

In this corpus the term is used across 4 chapters, led by Water Supply and Distribution in the IPC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.

### What is a water outlet called?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IRC 2009 states, in Definitions: “A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of the supply system.” It is defined in IRC 2009, IPC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording.

### What is the definition of a building drain?

Building Drain is a separate defined term. The IRC 2009 defines it as: “The lowest piping that collects the discharge from all other drainage piping inside the house and extends 30 inches (762 mm) in developed length of pipe, beyond the exterior walls and conveys the drainage to the building sewer.” That is not the same as water outlet, which the IRC 2009 defines as “A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

### What is the code for bathroom outlets?

Bathroom is a separate defined term. The IRC 2009 defines it as: “An area, including a basin, with one or more of the following: a toilet, a tub or a shower.” That is not the same as water outlet, which the IRC 2009 defines as “A valved discharge opening, including a hose bibb, through which water is removed from the potable water system supplying water to a plumbing fixture or plumbing appliance that requires either an air gap or backflow prevention device for protection of …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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