# Appliance, Existing: Building Code Definition

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

- Canonical: https://harth.build/resources/glossary/appliance-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 | IMC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IMC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 4 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Appliance, existing is a defined term in the International Mechanical Code (IMC) 2009, in Definitions. The code's own words are: “Any appliance regulated by this code which was legally installed prior to the effective date of this code, or for which a permit to install has been issued.” 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 4 chapters of this corpus, most often in Fuel Gas (IRC 2009), Building Services and Systems (IFC 2009), Chimneys and Vents (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](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?

**Appliance, Existing** — IMC 2009, Definitions:

> Any appliance regulated by this code which was legally installed prior to the effective date of this code, or for which a permit to install has been issued.

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

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

## What must be verified before using this guidance?

**Appliance, Existing** is defined once in this corpus, in the [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) chapter of the International Mechanical Code (IMC) 2009:

> Any appliance regulated by this code which was legally installed prior to the effective date of this code, or for which a permit to install has been issued.

## Where appliance, existing is used in the code

The term appears in 4 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 2 |
| [Building Services and Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md) | IFC 2009 | 1 |
| [Chimneys and Vents](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/chimneys-and-vents.md) | IMC 2009 | 1 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | IMC 2009 | 1 |

### The term in use

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

> Before replacing an existing appliance or connecting a vent connectorto a chimney, the chimneypassageway shall be examined to ascertain that it is clear and free of obstructions and it shall be cleaned ifpreviously used for venting solid or liquid fuel-burning appliances or fireplaces.

— [IRC 2009 §G2427.5.5](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md)

> An automatic vent damper device shall not be installed on an existing appliance unless the appliance is listed and labeled and the device is installed in accordance with the terms of its listing.

— [IMC 2009 §803.6](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/chimneys-and-vents.md)


## Appliance, Existing compared with Equipment, Existing

These two are the closest pair in the 2009 I-Codes: about 92 per cent of their defining words are the same. The code states both and compares neither, so the difference is worth naming.

| | Wording unique to it |
| --- | --- |
| **Appliance, Existing** (IMC 2009) | appliance |
| [Equipment, Existing](https://harth.build/resources/glossary/equipment-existing.md) (IMC 2009) | equipment |

Everything else in the two definitions is shared. If a project turns on which of the two applies, those words are the whole of the test — and a local amendment that edits one of them without editing the other moves the boundary between appliance, existing and equipment, existing.

## The terms appliance, existing 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 appliance, existing covers:

- **[Appliance](https://harth.build/resources/glossary/appliance.md)** — IRC 2009: Utilization equipment, normally built in standardized sizes or types, that is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, etc.
- **[Permit](https://harth.build/resources/glossary/permit.md)** — IBC 2009: An official document or certificate issued by the authority having jurisdiction which authorizes performance of a specified activity.

## Appliance, 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 IMC | Definitions | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Re-check the requirement that uses it | Building Services and Systems (IFC 2009) | |
| Re-check the requirement that uses it | Chimneys and Vents (IMC 2009) | |
| Re-check the requirement that uses it | Definitions (IMC 2009) | |
| Confirm the dependent definition | Appliance | |
| Confirm the dependent definition | Permit | |
| 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)
- [Appliance: Building Code Definition](https://harth.build/resources/glossary/appliance.md)
- [Permit: Building Code Definition](https://harth.build/resources/glossary/permit.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 appliance, existing?

The International Mechanical Code (IMC) 2009 defines it in Definitions as: “Any appliance regulated by this code which was legally installed prior to the effective date of this code, or for which a permit to install has been issued.” 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 appliance, existing?

In this corpus the term is used across 4 chapters, led by Fuel Gas in the IRC 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 fuel-fired appliance?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “Any appliance regulated by this code which was legally installed prior to the effective date of this code, or for which a permit to install has been issued.” 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 building code requirements?

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 appliance, existing, which the IMC 2009 defines as “Any appliance regulated by this code which was legally installed prior to the effective date of this code, or for which a permit to install has been issued.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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