Building Code Glossary
Wall: Building Code Definition
How the IBC 2009 define wall, 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
Wall is a defined term in the International Building Code (IBC) 2009, in Masonry. The code's own words are: “A vertical element with a horizontallength-to-thickness ratio greater than three, used to enclose space.” No other I-Code in this corpus defines it, so the IBC 2009 definition is the one to work from. The term is used in 125 chapters of this corpus, most often in Wall Construction (IRC 2009), Fire and Smoke Protection Features (IBC 2009), Foundations (IRC 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?
Wall — IBC 2009, Masonry:
A vertical element with a horizontallength-to-thickness ratio greater than three, used to enclose space.
What must be verified before using this guidance?
Wall is defined once in this corpus, in the Masonry chapter of the International Building Code (IBC) 2009:
A vertical element with a horizontallength-to-thickness ratio greater than three, used to enclose space.
Where wall is used in the code
The term appears in 125 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Wall Construction | IRC 2009 | 1740 |
| Fire and Smoke Protection Features | IBC 2009 | 844 |
| Foundations | IRC 2009 | 798 |
| Wood | IBC 2009 | 552 |
| Building Planning | IRC 2009 | 542 |
| Soils and Foundations | IBC 2009 | 301 |
| Masonry | IBC 2009 | 239 |
| Concrete | IBC 2009 | 225 |
| Fuel Gas | IRC 2009 | 186 |
| Exterior Walls | IBC 2009 | 184 |
| Structural Design | IBC 2009 | 182 |
| Wall Covering | IRC 2009 | 175 |
113 further chapters mention the term.
The term in use
How the code actually writes about wall, quoted from the 2009 text hosted here:
Wall construction shall be capable of accommodating all loads imposed according to Section R301 and of transmitting the resulting loads to the supporting structural elements.
When evidence is furnished to show that the wall was tested with the least fire-resistant side exposed to the furnace, subject to acceptance of the building official, the wall need not be subjected to tests from the opposite side (see Section 705.5 for exterior walls).
Fasteners used below grade to attach plywood to the exterior side of exterior basement or crawl-space wall studs, or fasteners used in knee wall construction, shall be of Type 304 or 316 stainless steel.
Wall: 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 IBC | Masonry | |
| Re-check the requirement that uses it | Wall Construction (IRC 2009) | |
| Re-check the requirement that uses it | Fire and Smoke Protection Features (IBC 2009) | |
| Re-check the requirement that uses it | Foundations (IRC 2009) | |
| Re-check the requirement that uses it | Wood (IBC 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
- Chimney: Building Code Definition
- Tile: Building Code Definition
- Fireplace: Building Code Definition
- Masonry: 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 wall?
The International Building Code (IBC) 2009 defines it in Masonry as: “A vertical element with a horizontallength-to-thickness ratio greater than three, used to enclose space.” 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 wall?
In this corpus the term is used across 125 chapters, led by Wall Construction 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 legal definition of a wall?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IBC 2009 states, in Masonry: “A vertical element with a horizontallength-to-thickness ratio greater than three, used to enclose space.” It is defined in IBC 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 definition of a wall in a building?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IBC 2009 states, in Masonry: “A vertical element with a horizontallength-to-thickness ratio greater than three, used to enclose space.” It is defined in IBC 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.
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