Building Code Glossary
Design Pressure: Building Code Definition
How the IFC 2009 define design pressure, 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
Design pressure is a defined term in the International Fire Code (IFC) 2009, in Hazardous Materials-general Provisions. The code's own words are: “The maximum gauge pressure that a pressure vessel, device, component or system is designed to withstand safely under the temperature and conditions of use expected.” 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 19 chapters of this corpus, most often in Wall Construction (IRC 2009), Glass and Glazing (IBC 2009), Structural Tests and Special Inspections (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?
Design Pressure — IFC 2009, Hazardous Materials-general Provisions:
The maximum gauge pressure that a pressure vessel, device, component or system is designed to withstand safely under the temperature and conditions of use expected.
What must be verified before using this guidance?
Design Pressure is defined once in this corpus, in the Hazardous Materials-general Provisions chapter of the International Fire Code (IFC) 2009:
The maximum gauge pressure that a pressure vessel, device, component or system is designed to withstand safely under the temperature and conditions of use expected.
Where design pressure is used in the code
The term appears in 19 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 | 18 |
| Glass and Glazing | IBC 2009 | 12 |
| Structural Tests and Special Inspections | IBC 2009 | 11 |
| Structural Design | IBC 2009 | 8 |
| Refrigeration | IMC 2009 | 7 |
| Cryogenic Fluids | IFC 2009 | 6 |
| Fire Protection Systems | IFC 2009 | 5 |
| Fire Protection Systems | IBC 2009 | 4 |
| Flammable and Combustible Liquids | IFC 2009 | 4 |
| Exhaust Systems | IMC 2009 | 4 |
| Building Services and Systems | IFC 2009 | 3 |
| Fuel Gas | IRC 2009 | 3 |
7 further chapters mention the term.
The term in use
How the code actually writes about design pressure, quoted from the 2009 text hosted here:
Where such calculated design pressures are used, they shall be validated by an additional test of the window or door unit having the highest allowable design pressure.
Unit skylights rated for the same performance grade for both positive and negative design pressure.
The design pressure rating of exterior windows and doors in buildings shall be determined in accordance with Section 1715.5.1 or 1715.5.2.
The terms design pressure is built out of
The definition above leans on 4 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what design pressure covers:
- Pressure Vessel — IFC 2009: A closed vessel designed to operate at pressures above 15 psig (103 kPa).
- Vessel — IFC 2009: A motorized watercraft, other than a seaplane on the water, used or capable of being used as a means of transportation.
- System — IFC 2009: An assembly of equipment consisting of a tank, container or containers, appurtenances, pumps, compressors and connecting piping.
- Device — IRC 2009: Aunit of an electrical system that carries or controls electrical energy as it principal function.
Design Pressure: 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 IFC | Hazardous Materials-general Provisions | |
| Re-check the requirement that uses it | Wall Construction (IRC 2009) | |
| Re-check the requirement that uses it | Glass and Glazing (IBC 2009) | |
| Re-check the requirement that uses it | Structural Tests and Special Inspections (IBC 2009) | |
| Re-check the requirement that uses it | Structural Design (IBC 2009) | |
| Confirm the dependent definition | Pressure Vessel | |
| Confirm the dependent definition | Vessel | |
| Confirm the dependent definition | System | |
| 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
- Pressure Vessel: Building Code Definition
- Vessel: Building Code Definition
- System: Building Code Definition
- Device: 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 design pressure?
The International Fire Code (IFC) 2009 defines it in Hazardous Materials-general Provisions as: “The maximum gauge pressure that a pressure vessel, device, component or system is designed to withstand safely under the temperature and conditions of use expected.” 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 design pressure?
In this corpus the term is used across 19 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 definition of design pressure?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IFC 2009 states, in Hazardous Materials-general Provisions: “The maximum gauge pressure that a pressure vessel, device, component or system is designed to withstand safely under the temperature and conditions of use expected.” 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.
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