Building Code Glossary
Machinery Room: Building Code Definition
How the IMC 2009 define machinery room, 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
Machinery room is a defined term in the International Mechanical Code (IMC) 2009, in Definitions. The code's own words are: “A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).” No other I-Code in this corpus defines it, so the IMC 2009 definition is the one to work from. The term is used in 10 chapters of this corpus, most often in Refrigeration (IMC 2009), Building Services and Systems (IFC 2009), Means of Egress (IBC 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?
Machinery Room — IMC 2009, Definitions:
A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).
What must be verified before using this guidance?
Machinery Room is defined once in this corpus, in the Definitions chapter of the International Mechanical Code (IMC) 2009:
A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).
Where machinery room is used in the code
The term appears in 10 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Refrigeration | IMC 2009 | 63 |
| Building Services and Systems | IFC 2009 | 18 |
| Means of Egress | IBC 2009 | 5 |
| Means of Egress | IFC 2009 | 5 |
| Definitions | IMC 2009 | 5 |
| Exhaust Systems | IMC 2009 | 4 |
| Fire Protection Systems | IBC 2009 | 1 |
| Fire Protection Systems | IFC 2009 | 1 |
| Specific Appliances, Fireplaces and Solid Fuel-burning Equipment | IMC 2009 | 1 |
| Fuel Gas | IRC 2009 | 1 |
The term in use
How the code actually writes about machinery room, quoted from the 2009 text hosted here:
Except as provided in Sections 1104.2.1 and 1104.2.2, all components containing the refrigerant shall be located either outdoors or in a machinery room where the quantity of refrigerant in an independent circuit of a system exceeds the amounts shown in Table 1103.1.
Remote control of the mechanical equipment and appliances located in the machinery room shall be provided at an approved location immediately outside the machinery room and adjacent to its principal entrance.
Machinery Room: 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 IMC | Definitions | |
| Re-check the requirement that uses it | Refrigeration (IMC 2009) | |
| Re-check the requirement that uses it | Building Services and Systems (IFC 2009) | |
| Re-check the requirement that uses it | Means of Egress (IBC 2009) | |
| Re-check the requirement that uses it | Means of Egress (IFC 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 machinery room?
The International Mechanical Code (IMC) 2009 defines it in Definitions as: “A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).” 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 machinery room?
In this corpus the term is used across 10 chapters, led by Refrigeration in the IMC 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 the definition of a machinery room in Ashrae Standard 15?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).” It is defined in IMC 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 are the requirements for ventilation in a machinery room?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).” It is defined in IMC 2009. It is not the same as Ventilation, which the IBC 2009 defines separately as “The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, any space.” 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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