Building Code Glossary
Tempered Water: Building Code Definition
How the IPC 2009 define tempered water, where the wording differs, and which chapters depend on the term.
On this page
Last updated September 7, 2026 · 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.
Direct answer
Tempered water is a defined term in the International Plumbing Code (IPC) 2009, in Definitions. The code's own words are: “Water having a temperature range between 85°F (29°C) and 110°F (43°C).” No other I-Code in this corpus defines it, so the IPC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Water Supply and Distribution (IPC 2009), Fixtures, Faucets and Fixture Fittings (IPC 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. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.
Content and cited inputs reviewed by Scott Barrington, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Tempered Water — IPC 2009, Definitions:
Water having a temperature range between 85°F (29°C) and 110°F (43°C).
What must be verified before using this guidance?
Tempered Water is defined once in this corpus, in the Definitions chapter of the International Plumbing Code (IPC) 2009:
Water having a temperature range between 85°F (29°C) and 110°F (43°C).
Where tempered water is used in the code
The term appears in 3 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 | IPC 2009 | 5 |
| Fixtures, Faucets and Fixture Fittings | IPC 2009 | 4 |
| Definitions | IPC 2009 | 1 |
The term in use
How the code actually writes about tempered water, quoted from the 2009 text hosted here:
In nonresidential occupancies, hot water or tempered water shall be supplied for bathing and washing purposes.
Tempered water shall be delivered from public hand-washing facilities.
Tempered Water: what to open, and in what order
Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.
| Check | Where | Confirmed |
|---|---|---|
| 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 | Fixtures, Faucets and Fixture Fittings (IPC 2009) | |
| Re-check the requirement that uses it | Definitions (IPC 2009) | |
| 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
- Building: Building Code Definition
- Construction Documents: Building Code Definition
- Registered Design Professional: Building Code Definition
- Dwelling Unit: Building Code Definition
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 publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.
Source links
Frequently asked questions
What is the code definition of tempered water?
The International Plumbing Code (IPC) 2009 defines it in Definitions as: “Water having a temperature range between 85°F (29°C) and 110°F (43°C).” 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 tempered water?
In this corpus the term is used across 3 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 considered tempered water?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IPC 2009 states, in Definitions: “Water having a temperature range between 85°F (29°C) and 110°F (43°C).” It is defined in 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.
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