Building Code Glossary
Load and Resistance Factor Design (LRFD): Building Code Definition
How the IBC 2009 define load and resistance factor design (lrfd), 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
Load and resistance factor design (lrfd) is a defined term in the International Building Code (IBC) 2009, in Structural Design. The code's own words are: “A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term "LRFD" is used in the design of steel and wood structures.” 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 3 chapters of this corpus, most often in Structural Design (IBC 2009), Definitions (IBC 2009), Wood (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?
Load and Resistance Factor Design (LRFD) — IBC 2009, Structural Design:
A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term "LRFD" is used in the design of steel and wood structures.
What must be verified before using this guidance?
Load and Resistance Factor Design (LRFD) is defined once in this corpus, in the Structural Design chapter of the International Building Code (IBC) 2009:
A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term "LRFD" is used in the design of steel and wood structures.
Where load and resistance factor design (lrfd) is used in the code
The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Structural Design | IBC 2009 | 4 |
| Definitions | IBC 2009 | 1 |
| Wood | IBC 2009 | 1 |
The terms load and resistance factor design (lrfd) 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 load and resistance factor design (lrfd) covers:
- Structure — IPC 2009: That which is built or constructed or a portion thereof.
- Steel — IFC 2009: Hot-or cold-rolled as defined by the International Building Code.
Load and Resistance Factor Design (LRFD): 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 | Structural Design (IBC 2009) | |
| Re-check the requirement that uses it | Definitions (IBC 2009) | |
| Re-check the requirement that uses it | Wood (IBC 2009) | |
| Confirm the dependent definition | Structure | |
| Confirm the dependent definition | Steel | |
| 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?
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 load and resistance factor design (lrfd)?
The International Building Code (IBC) 2009 defines it in Structural Design as: “A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term "LRFD" is used in the design of steel and wood structures.” 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 load and resistance factor design (lrfd)?
In this corpus the term is used across 3 chapters, led by Structural Design 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 ASD in steel design?
Steel is a separate defined term. The IFC 2009 defines it as: “Hot-or cold-rolled as defined by the International Building Code.” That is not the same as load and resistance factor design (lrfd), which the IBC 2009 defines as “A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term "LRFD" is used in the design of …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
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