Building Code Glossary
Story Above Grade Plane: Building Code Definition
How the IBC 2009, IRC 2009, IFC 2009 define story above grade plane, 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
Story above grade plane is a defined term in the International Building Code (IBC) 2009, in Definitions. The code's own words are: “Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is:” The IRC 2009, IFC 2009 define the same term with different wording, so the controlling text depends on which code governs the question in front of you — the comparison below sets the versions side by side. The term is used in 12 chapters of this corpus, most often in General Building Heights and Areas (IBC 2009), Wood (IBC 2009), Special Detailed Requirements Based on Use and Occupancy (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?
Story Above Grade Plane — IBC 2009, Definitions:
Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is:
What must be verified before using this guidance?
Three of the I-Codes in this corpus define Story Above Grade Plane, and the wording is not identical — read the version that governs your question.
| Code | Where it is defined | Definition |
|---|---|---|
| IBC 2009 | Definitions | Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is: |
| IRC 2009 | Definitions | Any storyhaving its finished floor surface entirely above grade plane, except that a basement shall be considered as a story above grade plane where the finished surface of the floor above the basement meets anyone of the following: |
| IFC 2009 | Definitions | Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is: |
Where story above grade plane is used in the code
The term appears in 12 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| General Building Heights and Areas | IBC 2009 | 27 |
| Wood | IBC 2009 | 8 |
| Special Detailed Requirements Based on Use and Occupancy | IBC 2009 | 5 |
| Soils and Foundations | IBC 2009 | 4 |
| Fire Protection Systems | IBC 2009 | 3 |
| Means of Egress | IBC 2009 | 3 |
| Fire Protection Systems | IFC 2009 | 3 |
| Definitions | IRC 2009 | 3 |
| Definitions | IFC 2009 | 2 |
| Means of Egress | IFC 2009 | 2 |
| Definitions | IBC 2009 | 1 |
| Plastic | IBC 2009 | 1 |
The term in use
How the code actually writes about story above grade plane, quoted from the 2009 text hosted here:
Where a building is equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the building area limitation in Table 503 is permitted to be increased by an additional 200 percent (
= 2) for buildings with more than one story above grade plane and an additional 300 percent (= 3) for buildings with no more than one …
Structures of conventional light-frame construction shall not exceed one story above grade plane in Seismic Design Category D or E.
Where a basement is considered a story above grade plane and the finished ground level adjacent to the basement wall is below the basement floor elevation for 25 percent or more of the perimeter, the floor and walls shall be dampproofed in accordance with Section 1805.2 and a foundation drain shall be installed in accordance with Section 1805.4.2.
The terms story above grade plane is built out of
The definition above leans on 5 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what story above grade plane covers:
- Grade Plane — IBC 2009: A reference plane representing the average of finished ground level adjoining the building at exterior walls.
- Basement — IBC 2009: A story that is not a storyabovegrade plane (see "Story above grade plane" in Section 202).
- Story — IBC 2009: That portion ofa building included between the upper surface of a floor and the upper surface of the floor or roof next above (also see "Basement," "Mezzanine" and Section 502.1).
- Grade — IRC 2009: The finished ground level adjoining the building at all exterior walls.
- Shall — IRC 2009: The term, when used in the code, is construed as mandatory.
Story Above Grade Plane: 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 | Definitions | |
| Read the definition in the adopted IRC | Definitions | |
| Read the definition in the adopted IFC | Definitions | |
| Re-check the requirement that uses it | General Building Heights and Areas (IBC 2009) | |
| Re-check the requirement that uses it | Wood (IBC 2009) | |
| Re-check the requirement that uses it | Special Detailed Requirements Based on Use and Occupancy (IBC 2009) | |
| Re-check the requirement that uses it | Soils and Foundations (IBC 2009) | |
| Confirm the dependent definition | Grade Plane | |
| Confirm the dependent definition | Basement | |
| Confirm the dependent definition | Story | |
| 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
- Grade Plane: Building Code Definition
- Basement: Building Code Definition
- Story: Building Code Definition
- Grade: 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 story above grade plane?
The International Building Code (IBC) 2009 defines it in Definitions as: “Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is:” 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 story above grade plane?
In this corpus the term is used across 12 chapters, led by General Building Heights and Areas 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.
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