Building Code Glossary
Strength, Required: Building Code Definition
How the IBC 2009 define strength, required, 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
Strength, required is a defined term in the International Building Code (IBC) 2009, in Structural Design. The code's own words are: “Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.” 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 5 chapters of this corpus, most often in Concrete (IBC 2009), Definitions (IBC 2009), Masonry (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, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Strength, Required — IBC 2009, Structural Design:
Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.
What must be verified before using this guidance?
Strength, Required is defined once in this corpus, in the Structural Design chapter of the International Building Code (IBC) 2009:
Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.
Where strength, required is used in the code
The term appears in 5 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Concrete | IBC 2009 | 2 |
| Definitions | IBC 2009 | 2 |
| Masonry | IBC 2009 | 2 |
| Structural Design | IBC 2009 | 1 |
| Wall Construction | IRC 2009 | 1 |
The term in use
How the code actually writes about strength, required, quoted from the 2009 text hosted here:
The required strength and durability of concrete shall be determined by compliance with the proportioning' testing, mixing and placing provisions of Sections 1905.1.1 through 1905.13.
Chases and recesses in masonry walls shall be designed and constructed so as not to reduce the required strength or required fire resistance of the wall and in no case shall a chase or recess be permitted within the required area of a pier.
The terms strength, required is built out of
The definition above leans on 1 other defined term. Each carries its own code definition, and a local amendment to any of them changes what strength, required covers:
- Loads — IBC 2009: Forces or other actions that result from the weight of building materials, occupants and their possessions, environmental effects, differential movement and restrained dimensional changes.
Strength, Required: 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 | Structural Design | |
| Re-check the requirement that uses it | Concrete (IBC 2009) | |
| Re-check the requirement that uses it | Definitions (IBC 2009) | |
| Re-check the requirement that uses it | Masonry (IBC 2009) | |
| Re-check the requirement that uses it | Structural Design (IBC 2009) | |
| Confirm the dependent definition | Loads | |
| 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
- Loads: Building Code Definition
- Design Flood Elevation: Building Code Definition
- Seismic Design Category: Building Code Definition
- Design Flood: 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 strength, required?
The International Building Code (IBC) 2009 defines it in Structural Design as: “Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.” 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 strength, required?
In this corpus the term is used across 5 chapters, led by Concrete 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 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 strength, required, which the IBC 2009 defines as “Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
What is the definition of a structure according to the building code?
Structure is a separate defined term. The IPC 2009 defines it as: “That which is built or constructed or a portion thereof.” That is not the same as strength, required, which the IBC 2009 defines as “Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
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