# Control: Building Code Definition > How the IRC 2009, IMC 2009 define control, where the wording differs, and which chapters depend on the term. - Canonical: https://harth.build/resources/glossary/control/ - 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 | IRC 2009, IMC 2009 (2009 editions transcribed in this corpus) | | Primary source | IRC 2009 Fuel Gas (model text, not a jurisdiction's adopted text) | | Chapters using the term | 170 (counted across the codes hosted here) | | Wording identical across codes | Yes (compare before citing one code's wording under another) | ## Direct answer Control is a defined term in the International Residential Code (IRC) 2009, in Fuel Gas. The code's own words are: “A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system.” The IMC 2009 carries the same definition word for word, so the term means the same thing in each. The term is used in 170 chapters of this corpus, most often in Fire Protection Systems (IFC 2009), Fire Protection Systems (IBC 2009), Commercial Energy Efficiency (IECC 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](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? **Control** — IRC 2009, Fuel Gas: > A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system. ![Labeled code-term definition diagram: Control: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/control/diagram-1344.webp) *How the IRC 2009, IMC 2009 define control, where the wording differs, and which chapters depend on the term.* ## What must be verified before using this guidance? Two of the I-Codes in this corpus define **Control**, in identical words. | Code | Where it is defined | Definition | | --- | --- | --- | | IRC 2009 | [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system. | | IMC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system. | ## Where control is used in the code The term appears in 170 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next. | Chapter | Code | Mentions | | --- | --- | --- | | [Fire Protection Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/fire-protection-systems.md) | IFC 2009 | 365 | | [Fire Protection Systems](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-protection-systems.md) | IBC 2009 | 342 | | [Commercial Energy Efficiency](https://harth.build/resources/building-codes/us-states/maryland/iecc-2009/commercial-energy-efficiency.md) | IECC 2009 | 332 | | [Hazardous Materials-general Provisions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md) | IFC 2009 | 282 | | [Flammable and Combustible Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md) | IFC 2009 | 276 | | [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 | 207 | | [Exhaust Systems](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/exhaust-systems.md) | IMC 2009 | 142 | | [Fire and Smoke Protection Features](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-and-smoke-protection-features.md) | IBC 2009 | 114 | | [Motor Fuel-dispensing Facilities and Repair Garages](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/motor-fuel-dispensing-facilities-and-repair-garages.md) | IFC 2009 | 88 | | [Highly Toxic and Toxic Materials](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/highly-toxic-and-toxic-materials.md) | IFC 2009 | 78 | | [Duct Systems](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/duct-systems.md) | IMC 2009 | 74 | | [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 61 | _158 further chapters mention the term._ ### The term in use How the code actually writes about control, quoted from the 2009 text hosted here: > The tag shall be posted at each fire department connection, system control valve, fire alarm control unit, fire alarm annunciator and fire command center, indicating which system, or part thereof, has been removed from service. — [IFC 2009 §901.7.3](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/fire-protection-systems.md) > Cooling systems shall not use hot gas bypass or other evaporator pressure control systems unless the system is designed with multiple steps of unloading or continuous capacity modulation. — [IECC 2009 §502.4.4](https://harth.build/resources/building-codes/us-states/maryland/iecc-2009/commercial-energy-efficiency.md) > Prevention, control and mitigation of dangerous conditions related to storage, dispensing, use and handling of hazardous materials shall be in accordance with this chapter. — [IFC 2009 §2701.1](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md) ## The terms control 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 control covers: - **[Mechanical System](https://harth.build/resources/glossary/mechanical-system.md)** — IRC 2009: A system specifically addressed and regulated in this code and composed of components, devices, appliances and equipment. - **[Automatic](https://harth.build/resources/glossary/automatic.md)** — IBC 2009: As applied to fire protection devices, a device or system providing an emergency function without the necessity for human intervention and activated as a result of a predetermined temperature rise, rate of temperature rise or combustion products. - **[System](https://harth.build/resources/glossary/system.md)** — IFC 2009: An assembly of equipment consisting of a tank, container or containers, appurtenances, pumps, compressors and connecting piping. - **[Device](https://harth.build/resources/glossary/device.md)** — IRC 2009: Aunit of an electrical system that carries or controls electrical energy as it principal function. - **[Manual](https://harth.build/resources/glossary/manual.md)** — IECC 2009: Capable of being operated by personal intervention (see "Automatic"). ## Control: 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 IRC | Fuel Gas | | | Read the definition in the adopted IMC | Definitions | | | Re-check the requirement that uses it | Fire Protection Systems (IFC 2009) | | | Re-check the requirement that uses it | Fire Protection Systems (IBC 2009) | | | Re-check the requirement that uses it | Commercial Energy Efficiency (IECC 2009) | | | Re-check the requirement that uses it | Hazardous Materials-general Provisions (IFC 2009) | | | Confirm the dependent definition | Mechanical System | | | Confirm the dependent definition | Automatic | | | 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](https://harth.build/resources/glossary.md) - [Mechanical System: Building Code Definition](https://harth.build/resources/glossary/mechanical-system.md) - [Automatic: Building Code Definition](https://harth.build/resources/glossary/automatic.md) - [System: Building Code Definition](https://harth.build/resources/glossary/system.md) - [Manual: Building Code Definition](https://harth.build/resources/glossary/manual.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 control? The International Residential Code (IRC) 2009 defines it in Fuel Gas as: “A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system.” 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 control? In this corpus the term is used across 170 chapters, led by Fire Protection Systems 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 the main Building Code in Malaysia? 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 control, which the IRC 2009 defines as “A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted. ### What is a control code? In the 2009 I-Codes hosted here it is a defined term rather than a description. The IRC 2009 states, in Fuel Gas: “A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system.” It is defined in IRC 2009, IMC 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. --- - Continue in Harth (open this topic in the Harth agent): https://app.harth.build/agent?context=%2Fresources%2Fglossary%2Fcontrol%2F - View this page in a browser: https://harth.build/resources/glossary/control/ - All resources for agents: https://harth.build/llms.txt