Building Code Glossary
Furnace Room: Building Code Definition
How the IMC 2009 define furnace 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
Furnace room is a defined term in the International Mechanical Code (IMC) 2009, in Definitions. The code's own words are: “A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").” 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 7 chapters of this corpus, most often in Means of Egress (IBC 2009), Means of Egress (IFC 2009), Definitions (IMC 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?
Furnace Room — IMC 2009, Definitions:
A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").
What must be verified before using this guidance?
Furnace Room is defined once in this corpus, in the Definitions chapter of the International Mechanical Code (IMC) 2009:
A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").
Where furnace room is used in the code
The term appears in 7 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Means of Egress | IBC 2009 | 2 |
| Means of Egress | IFC 2009 | 2 |
| Definitions | IMC 2009 | 1 |
| General Regulations | IMC 2009 | 1 |
| Specific Appliances, Fireplaces and Solid Fuel-burning Equipment | IMC 2009 | 1 |
| Duct Systems | IRC 2009 | 1 |
| Fuel Gas | IRC 2009 | 1 |
The terms furnace room is built out of
The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what furnace room covers:
- Boiler Room — IMC 2009: A room primarily utilized for the installation of a boiler.
- Boiler — IRC 2009: A self-contained appliance from which hot water is circulated for heating purposes and then returned to the boiler, and which operates at water pressures not exceeding 160 pounds per square inch gage (psig) (1102 kPa gauge) and at water temperatures …
Furnace 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 | Means of Egress (IBC 2009) | |
| Re-check the requirement that uses it | Means of Egress (IFC 2009) | |
| Re-check the requirement that uses it | Definitions (IMC 2009) | |
| Re-check the requirement that uses it | General Regulations (IMC 2009) | |
| Confirm the dependent definition | Boiler Room | |
| Confirm the dependent definition | Boiler | |
| 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
- Boiler Room: Building Code Definition
- Boiler: 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 furnace room?
The International Mechanical Code (IMC) 2009 defines it in Definitions as: “A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").” 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 furnace room?
In this corpus the term is used across 7 chapters, led by Means of Egress in the IBC 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 does furnace room mean?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").” 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 is the code requirement for clearance around a furnace?
Clearance is a separate defined term. The IRC 2009 defines it as: “The minimum distance through air measured between the heat-producing surface of the mechanical appliance, device or equipment and the surface of the combustible material or assembly.” That is not the same as furnace room, which the IMC 2009 defines as “A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
What are the requirements for doors in a boiler room?
Boiler Room is a separate defined term. The IMC 2009 defines it as: “A room primarily utilized for the installation of a boiler.” That is not the same as furnace room, which the IMC 2009 defines as “A room primarily utilized for the installation of fuel-burning, space-heating and water-heating appliances other than boilers (see also "Boiler room").” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
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