# Membrane Structure: Building Code Definition

> How the IFC 2009 define membrane structure, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/membrane-structure/
- Last updated: 2026-09-07
- Data source: 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.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IFC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IFC 2009 Tents and Other Membrane Structures (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 9 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Membrane structure is a defined term in the International Fire Code (IFC) 2009, in Tents and Other Membrane Structures. The code's own words are: “An air-inflated, air-supported, cable or frame-covered structure as defined by the International BUilding Code and not otherwise defined as a tent. See Chapter 31 of the International BUilding Code.” No other I-Code in this corpus defines it, so the IFC 2009 definition is the one to work from. The term is used in 9 chapters of this corpus, most often in Tents and Other Membrane Structures (IFC 2009), Special Construction (IBC 2009), Building Services and Systems (IFC 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](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Membrane Structure** — IFC 2009, Tents and Other Membrane Structures:

> An air-inflated, air-supported, cable or frame-covered structure as defined by the International BUilding Code and not otherwise defined as a tent. See Chapter 31 of the International BUilding Code.

![Labeled code-term definition diagram: Membrane Structure: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/membrane-structure/diagram-1344.webp)

*How the IFC 2009 define membrane structure, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Membrane Structure** is defined once in this corpus, in the [Tents and Other Membrane Structures](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/tents-and-other-membrane-structures.md) chapter of the International Fire Code (IFC) 2009:

> An air-inflated, air-supported, cable or frame-covered structure as defined by the International BUilding Code and not otherwise defined as a tent. See Chapter 31 of the International BUilding Code.

## Where membrane structure is used in the code

The term appears in 9 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Tents and Other Membrane Structures](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/tents-and-other-membrane-structures.md) | IFC 2009 | 111 |
| [Special Construction](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-construction.md) | IBC 2009 | 22 |
| [Building Services and Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md) | IFC 2009 | 10 |
| [Scope and Administration](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/scope-and-administration.md) | IFC 2009 | 8 |
| [Electrical](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/electrical.md) | IBC 2009 | 4 |
| [Fire Protection Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/fire-protection-systems.md) | IFC 2009 | 2 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/definitions.md) | IBC 2009 | 1 |
| [Special Detailed Requirements Based on Use and Occupancy](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-detailed-requirements-based-on-use-and-occupancy.md) | IBC 2009 | 1 |
| [Definitions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/definitions.md) | IFC 2009 | 1 |

### The term in use

How the code actually writes about membrane structure, quoted from the 2009 text hosted here:

> The tent or membrane structure floor plan shall indicate details of the means of egress facilities, seating capacity, arrangement of the seating and location and type of heating and electrical equipment.

— [IFC 2009 §2403.6](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/tents-and-other-membrane-structures.md)

> The area of a membrane structure shall not exceed the limitations set forth in Table 503, except as provided in Section 506.

— [IBC 2009 §3102.4](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-construction.md)

> An operational permit is required to operate an air-supported temporary membrane structure or a tent having an area in excess of 400 square feet (37 m2).

— [IFC 2009 §105.6.43](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/scope-and-administration.md)


## The terms membrane structure 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 membrane structure covers:

- **[Structure](https://harth.build/resources/glossary/structure.md)** — IPC 2009: That which is built or constructed or a portion thereof.
- **[Building](https://harth.build/resources/glossary/building.md)** — IBC 2009: Any structure used or intended for supporting or sheltering any use or occupancy.

## Membrane Structure: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IFC | Tents and Other Membrane Structures | |
| Re-check the requirement that uses it | Tents and Other Membrane Structures (IFC 2009) | |
| Re-check the requirement that uses it | Special Construction (IBC 2009) | |
| Re-check the requirement that uses it | Building Services and Systems (IFC 2009) | |
| Re-check the requirement that uses it | Scope and Administration (IFC 2009) | |
| Confirm the dependent definition | Structure | |
| Confirm the dependent definition | Building | |
| 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](https://harth.build/resources/glossary.md)
- [Structure: Building Code Definition](https://harth.build/resources/glossary/structure.md)
- [Building: Building Code Definition](https://harth.build/resources/glossary/building.md)

## 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](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.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of membrane structure?

The International Fire Code (IFC) 2009 defines it in Tents and Other Membrane Structures as: “An air-inflated, air-supported, cable or frame-covered structure as defined by the International BUilding Code and not otherwise defined as a tent. See Chapter 31 of the International BUilding Code.” 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 membrane structure?

In this corpus the term is used across 9 chapters, led by Tents and Other Membrane Structures in the IFC 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 membrane structure?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IFC 2009 states, in Tents and Other Membrane Structures: “An air-inflated, air-supported, cable or frame-covered structure as defined by the International BUilding Code and not otherwise defined as a tent. See Chapter 31 of the International BUilding Code.” It is defined in IFC 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 considered a structure in building code?

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 membrane structure, which the IFC 2009 defines as “An air-inflated, air-supported, cable or frame-covered structure as defined by the International BUilding Code and not otherwise defined as a tent. See Chapter 31 of the International BUilding Code.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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