# Premises Wiring (System): Building Code Definition > How the IRC 2009 define premises wiring (system), where the wording differs, and which chapters depend on the term. - Canonical: https://harth.build/resources/glossary/premises-wiring-system/ - 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 (2009 editions transcribed in this corpus) | | Primary source | IRC 2009 Electrical Definitions (model text, not a jurisdiction's adopted text) | | Chapters using the term | 1 (counted across the codes hosted here) | | Wording identical across codes | Single code (compare before citing one code's wording under another) | ## Direct answer Premises wiring (system) is a defined term in the International Residential Code (IRC) 2009, in Electrical Definitions. The code's own words are: “Interior and exterior wiring, including power, lighting, control and signal circuit wiring together with all of their associated hardware, fittings and wiring devices, both permanently and temporarily installed. This includes wiring from the service point or power source to the outlets and wiring from and including the power source to the outlets where there is …” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 1 chapters of this corpus, most often in Electrical Definitions (IRC 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? **Premises Wiring (System)** — IRC 2009, Electrical Definitions: > Interior and exterior wiring, including power, lighting, control and signal circuit wiring together with all of their associated hardware, fittings and wiring devices, both permanently and temporarily installed. This includes wiring from the service point or power source to the outlets and wiring from and including the power source to the outlets where there is no service point. Such wiring does not include wiring internal to appliances, luminaires, motors, controllers, and similar equipment. ![Labeled code-term definition diagram: Premises Wiring (System): Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/premises-wiring-system/diagram-1344.webp) *How the IRC 2009 define premises wiring (system), where the wording differs, and which chapters depend on the term.* ## What must be verified before using this guidance? **Premises Wiring (System)** is defined once in this corpus, in the [Electrical Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/electrical-definitions.md) chapter of the International Residential Code (IRC) 2009: > Interior and exterior wiring, including power, lighting, control and signal circuit wiring together with all of their associated hardware, fittings and wiring devices, both permanently and temporarily installed. This includes wiring from the service point or power source to the outlets and wiring from and including the power source to the outlets where there is no service point. Such wiring does not include wiring internal to appliances, luminaires, motors, controllers, and similar equipment. ## Where premises wiring (system) is used in the code The term appears in 1 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next. | Chapter | Code | Mentions | | --- | --- | --- | | [Electrical Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/electrical-definitions.md) | IRC 2009 | 1 | ## The terms premises wiring (system) is built out of The definition above leans on 3 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what premises wiring (system) covers: - **[Equipment](https://harth.build/resources/glossary/equipment.md)** — IRC 2009: All piping, ducts, vents, control devices and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings. - **[Control](https://harth.build/resources/glossary/control.md)** — IRC 2009: A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system. - **[Service](https://harth.build/resources/glossary/service.md)** — IRC 2009: The conductors and equipment for delivering energy from the serving utility to the wiring system of the premises served. ## Premises Wiring (System): 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 | Electrical Definitions | | | Re-check the requirement that uses it | Electrical Definitions (IRC 2009) | | | Confirm the dependent definition | Equipment | | | Confirm the dependent definition | Control | | | Confirm the dependent definition | Service | | | 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) - [Equipment: Building Code Definition](https://harth.build/resources/glossary/equipment.md) - [Service: Building Code Definition](https://harth.build/resources/glossary/service.md) - [Control: Building Code Definition](https://harth.build/resources/glossary/control.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 premises wiring (system)? The International Residential Code (IRC) 2009 defines it in Electrical Definitions as: “Interior and exterior wiring, including power, lighting, control and signal circuit wiring together with all of their associated hardware, fittings and wiring devices, both permanently and temporarily installed. This includes wiring from the service point or power source to the outlets and wiring from and including the power source to the outlets where there is no service point. Such wiring does not include wiring internal to appliances, luminaires, motors, controllers, and similar equipment.” 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 premises wiring (system)? In this corpus the term is used across 1 chapters, led by Electrical Definitions 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. --- - Continue in Harth (open this topic in the Harth agent): https://app.harth.build/agent?context=%2Fresources%2Fglossary%2Fpremises-wiring-system%2F - View this page in a browser: https://harth.build/resources/glossary/premises-wiring-system/ - All resources for agents: https://harth.build/llms.txt