# Existing: Building Code Definition

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

- Canonical: https://harth.build/resources/glossary/existing/
- 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 Construction Requirements for Existing Buildings (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 71 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Existing is a defined term in the International Fire Code (IFC) 2009, in Construction Requirements for Existing Buildings. The code's own words are: “Buildings, facilities or conditions that are already in existence, constructed or officially authorized prior to the adoption of this code.” 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 71 chapters of this corpus, most often in Existing Structures (IBC 2009), Construction Requirements for Existing Buildings (IFC 2009), Roof Assemblies and Rooftop Structures (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?

**Existing** — IFC 2009, Construction Requirements for Existing Buildings:

> Buildings, facilities or conditions that are already in existence, constructed or officially authorized prior to the adoption of this code.

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

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

## What must be verified before using this guidance?

**Existing** is defined once in this corpus, in the [Construction Requirements for Existing Buildings](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/construction-requirements-for-existing-buildings.md) chapter of the International Fire Code (IFC) 2009:

> Buildings, facilities or conditions that are already in existence, constructed or officially authorized prior to the adoption of this code.

## Where existing is used in the code

The term appears in 71 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Existing Structures](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/existing-structures.md) | IBC 2009 | 169 |
| [Construction Requirements for Existing Buildings](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/construction-requirements-for-existing-buildings.md) | IFC 2009 | 98 |
| [Roof Assemblies and Rooftop Structures](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/roof-assemblies-and-rooftop-structures.md) | IBC 2009 | 35 |
| [Administration](https://harth.build/resources/building-codes/us-states/maryland/iecc-2009/administration.md) | IECC 2009 | 33 |
| [Fire Protection Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/fire-protection-systems.md) | IFC 2009 | 31 |
| [Flammable and Combustible Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md) | IFC 2009 | 26 |
| [Scope and Administration](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/scope-and-administration.md) | IRC 2009 | 25 |
| [Interior Finish, Decorative Materials and Furnishings](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/interior-finish-decorative-materials-and-furnishings.md) | IFC 2009 | 22 |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 19 |
| [Semiconductor Fabrication Facilities](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/semiconductor-fabrication-facilities.md) | IFC 2009 | 18 |
| [Building Planning](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/building-planning.md) | IRC 2009 | 18 |
| [Fire Protection Systems](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-protection-systems.md) | IBC 2009 | 16 |

_59 further chapters mention the term._

### The term in use

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

> The provisions of this chapter shall control the alteration, repair, addition and change of occupancy of existing structures.

— [IBC 2009 §3401.1](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/existing-structures.md)

> The provisions of this chapter shall apply to existing buildings constructed prior to the adoption of this code.

— [IFC 2009 §4601.1](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/construction-requirements-for-existing-buildings.md)

> Materials and methods of application used for recovering or replacing an existing roof covering shall comply with the requirements of Chapter 15.

— [IBC 2009 §1510.1](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/roof-assemblies-and-rooftop-structures.md)

## Existing: 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 | Construction Requirements for Existing Buildings | |
| Re-check the requirement that uses it | Existing Structures (IBC 2009) | |
| Re-check the requirement that uses it | Construction Requirements for Existing Buildings (IFC 2009) | |
| Re-check the requirement that uses it | Roof Assemblies and Rooftop Structures (IBC 2009) | |
| Re-check the requirement that uses it | Administration (IECC 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)
- [Hood: Building Code Definition](https://harth.build/resources/glossary/hood.md)
- [Fire Code Official: Building Code Definition](https://harth.build/resources/glossary/fire-code-official.md)
- [Agent: Building Code Definition](https://harth.build/resources/glossary/agent.md)
- [Vessel: Building Code Definition](https://harth.build/resources/glossary/vessel.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 existing?

The International Fire Code (IFC) 2009 defines it in Construction Requirements for Existing Buildings as: “Buildings, facilities or conditions that are already in existence, constructed or officially authorized prior to the adoption of this code.” 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 existing?

In this corpus the term is used across 71 chapters, led by Existing Structures 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 the definition of an existing building?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IFC 2009 states, in Construction Requirements for Existing Buildings: “Buildings, facilities or conditions that are already in existence, constructed or officially authorized prior to the adoption of this code.” It is defined in IFC 2009. It is not the same as Building, which the IBC 2009 defines separately as “Any structure used or intended for supporting or sheltering any use or occupancy.” 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 meant by existing?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IFC 2009 states, in Construction Requirements for Existing Buildings: “Buildings, facilities or conditions that are already in existence, constructed or officially authorized prior to the adoption of this code.” 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.

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