# Occupancy Classification: Building Code Definition

> How the IFC 2009 define occupancy classification, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/occupancy-classification/
- 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 | IFC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IFC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 19 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Occupancy classification is a defined term in the International Fire Code (IFC) 2009, in Definitions. The code's own words are: “For the purposes of this code, certain occupancies are defined as follows:” No other I-Code in this corpus defines it, so the IFC 2009 definition is the one to work from. The term is used in 19 chapters of this corpus, most often in General Building Heights and Areas (IBC 2009), Existing Structures (IBC 2009), Use and Occupancy Classification (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](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?

**Occupancy Classification** — IFC 2009, Definitions:

> For the purposes of this code, certain occupancies are defined as follows:

![Labeled code-term definition diagram: Occupancy Classification: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/occupancy-classification/diagram-1344.webp)

*How the IFC 2009 define occupancy classification, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Occupancy Classification** is defined once in this corpus, in the [Definitions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/definitions.md) chapter of the International Fire Code (IFC) 2009:

> For the purposes of this code, certain occupancies are defined as follows:

## Where occupancy classification is used in the code

The term appears in 19 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [General Building Heights and Areas](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/general-building-heights-and-areas.md) | IBC 2009 | 13 |
| [Existing Structures](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/existing-structures.md) | IBC 2009 | 11 |
| [Use and Occupancy Classification](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/use-and-occupancy-classification.md) | IBC 2009 | 5 |
| [Refrigeration](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/refrigeration.md) | IMC 2009 | 4 |
| [Special Detailed Requirements Based on Use and Occupancy](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-detailed-requirements-based-on-use-and-occupancy.md) | IBC 2009 | 3 |
| [Flammable and Combustible Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md) | IFC 2009 | 3 |
| [Ventilation](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/ventilation.md) | IMC 2009 | 3 |
| [Interior Finishes](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/interior-finishes.md) | IBC 2009 | 2 |
| [Fire and Smoke Protection Features](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-and-smoke-protection-features.md) | IBC 2009 | 1 |
| [Plumbing Systems](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/plumbing-systems.md) | IBC 2009 | 1 |
| [Scope and Administration](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/scope-and-administration.md) | IBC 2009 | 1 |
| [Definitions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/definitions.md) | IFC 2009 | 1 |

_7 further chapters mention the term._

### The term in use

How the code actually writes about occupancy classification, quoted from the 2009 text hosted here:

> The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space.

— [IBC 2009 §508.2.2](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/general-building-heights-and-areas.md)

> A certificate of occupancy shall be issued where it has been determined that the requirements for the new occupancy classification have been met.

— [IBC 2009 §3408.2](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/existing-structures.md)

> Where equipment or appliances, other than piping, are located outside a building and within 20 feet (6096 mm) of any building opening, such equipment or appliances shall be governed by the occupancy classification of the building.

— [IMC 2009 §1103.2](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/refrigeration.md)

## Occupancy Classification: 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 IFC | Definitions | |
| Re-check the requirement that uses it | General Building Heights and Areas (IBC 2009) | |
| Re-check the requirement that uses it | Existing Structures (IBC 2009) | |
| Re-check the requirement that uses it | Use and Occupancy Classification (IBC 2009) | |
| Re-check the requirement that uses it | Refrigeration (IMC 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](https://harth.build/resources/glossary.md)
- [Building: Building Code Definition](https://harth.build/resources/glossary/building.md)
- [Construction Documents: Building Code Definition](https://harth.build/resources/glossary/construction-documents.md)
- [Registered Design Professional: Building Code Definition](https://harth.build/resources/glossary/registered-design-professional.md)
- [Dwelling Unit: Building Code Definition](https://harth.build/resources/glossary/dwelling-unit.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 occupancy classification?

The International Fire Code (IFC) 2009 defines it in Definitions as: “For the purposes of this code, certain occupancies are defined as follows:” 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 occupancy classification?

In this corpus the term is used across 19 chapters, led by General Building Heights and Areas 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 is an occupancy classification code?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IFC 2009 states, in Definitions: “For the purposes of this code, certain occupancies are defined as follows:” It is defined in IFC 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 different occupancy classifications in the North Carolina building code?

Building is a separate defined term. The IBC 2009 defines it as: “Any structure used or intended for supporting or sheltering any use or occupancy.” That is not the same as occupancy classification, which the IFC 2009 defines as “For the purposes of this code, certain occupancies are defined as follows:” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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