Building Code Glossary
Overload: Building Code Definition
How the IRC 2009 define overload, 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
Overload is a defined term in the International Residential Code (IRC) 2009, in Electrical Definitions. The code's own words are: “Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 11 chapters of this corpus, most often in Services (IRC 2009), Electrical Definitions (IRC 2009), Soils and Foundations (IBC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted.
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?
Overload — IRC 2009, Electrical Definitions:
Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.
What must be verified before using this guidance?
Overload is defined once in this corpus, in the Electrical Definitions chapter of the International Residential Code (IRC) 2009:
Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.
Where overload is used in the code
The term appears in 11 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Services | IRC 2009 | 7 |
| Electrical Definitions | IRC 2009 | 5 |
| Soils and Foundations | IBC 2009 | 3 |
| Explosives and Fireworks | IFC 2009 | 3 |
| Administration | IECC 2009 | 2 |
| General Regulations | IPC 2009 | 2 |
| Branch Circuit and Feeder Requirements | IRC 2009 | 2 |
| Scope and Administration | IMC 2009 | 1 |
| Scope and Administration | IPC 2009 | 1 |
| Mechanical Administration | IRC 2009 | 1 |
| Plumbing Administration | IRC 2009 | 1 |
The term in use
How the code actually writes about overload, quoted from the 2009 text hosted here:
Each ungrounded service conductor shall have overload protection.
To resist the effects of mislocation, compressive overload of deep foundation elements to 110 percent of the allowable design load shall be permitted.
Additions, alterations, renovations or repairs shall not create an unsafe or hazardous condition or overload existing building systems.
The terms overload is built out of
The definition above leans on 4 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what overload covers:
- Equipment — IRC 2009: All piping, ducts, vents, control devices and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings.
- Dangerous — IBC 2009: Any building or structure or portion thereof that meets any of the conditions described below shall be deemed dangerous:
- Conductor — IPC 2009: A pipe inside the building that conveys storm water from the roof to a storm or combined bUilding drain.
- Ampacity — IRC 2009: The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
Overload: 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 IRC | Electrical Definitions | |
| Re-check the requirement that uses it | Services (IRC 2009) | |
| Re-check the requirement that uses it | Electrical Definitions (IRC 2009) | |
| Re-check the requirement that uses it | Soils and Foundations (IBC 2009) | |
| Re-check the requirement that uses it | Explosives and Fireworks (IFC 2009) | |
| Confirm the dependent definition | Equipment | |
| Confirm the dependent definition | Dangerous | |
| Confirm the dependent definition | Conductor | |
| 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
- Equipment: Building Code Definition
- Dangerous: Building Code Definition
- Conductor: Building Code Definition
- Ampacity: 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 overload?
The International Residential Code (IRC) 2009 defines it in Electrical Definitions as: “Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.” 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 overload?
In this corpus the term is used across 11 chapters, led by Services 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 a-3 occupancy classification?
Occupancy Classification is a separate defined term. The IFC 2009 defines it as: “For the purposes of this code, certain occupancies are defined as follows:” That is not the same as overload, which the IRC 2009 defines as “Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
What is the dead load for a residential building?
Residential Building is a separate defined term. The IECC 2009 defines it as: “For this code, includes R-3 buildings, as well as R-2 and R-4 buildings three stories or less in height above grade.” That is not the same as overload, which the IRC 2009 defines as “Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
What does "overload" mean in C++?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IRC 2009 states, in Electrical Definitions: “Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.” It is defined in IRC 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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