# Skylights and Sloped Glazing: Building Code Definition > How the IBC 2009, IRC 2009 define skylights and sloped glazing, where the wording differs, and which chapters depend on the term. - Canonical: https://harth.build/resources/glossary/skylights-and-sloped-glazing/ - 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 | IBC 2009, IRC 2009 (2009 editions transcribed in this corpus) | | Primary source | IBC 2009 Definitions (model text, not a jurisdiction's adopted text) | | Chapters using the term | 3 (counted across the codes hosted here) | | Wording identical across codes | No (compare before citing one code's wording under another) | ## Direct answer Skylights and sloped glazing is a defined term in the International Building Code (IBC) 2009, in Definitions. The code's own words are: “Glass or other transparent or translucent glazing material installed at a slope of 15 degrees (0.26 rad) or more from vertical. Glazing material in skylights, including unit skylights, solariums, sunrooms, roofs and sloped walls, are included in this definition.” The IRC 2009 defines 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 3 chapters of this corpus, most often in Building Planning (IRC 2009), Roof Assemblies and Rooftop Structures (IBC 2009), Definitions (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](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? **Skylights and Sloped Glazing** — IBC 2009, Definitions: > Glass or other transparent or translucent glazing material installed at a slope of 15 degrees (0.26 rad) or more from vertical. Glazing material in skylights, including unit skylights, solariums, sunrooms, roofs and sloped walls, are included in this definition. ![Labeled code-term definition diagram: Skylights and Sloped Glazing: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/skylights-and-sloped-glazing/diagram-1344.webp) *How the IBC 2009, IRC 2009 define skylights and sloped glazing, 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 **Skylights and Sloped Glazing**, and the wording is not identical — read the version that governs your question. | Code | Where it is defined | Definition | | --- | --- | --- | | IBC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/definitions.md) | Glass or other transparent or translucent glazing material installed at a slope of 15 degrees (0.26 rad) or more from vertical. Glazing material in skylights, including unit skylights, solariums, sunrooms, roofs and sloped walls, are included in this definition. | | IRC 2009 | [Building Planning](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/building-planning.md) | Glass or other transparent or translucent glazing material installed at a slope of 15 degrees (0.26 rad) or more from vertical. Glazing materials in skylights, including unit skylights, solariums, sunrooms, roofs and sloped walls are included in this definition. | ## Where skylights and sloped glazing is used in the code The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next. | Chapter | Code | Mentions | | --- | --- | --- | | [Building Planning](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/building-planning.md) | IRC 2009 | 4 | | [Roof Assemblies and Rooftop Structures](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/roof-assemblies-and-rooftop-structures.md) | IBC 2009 | 2 | | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/definitions.md) | IBC 2009 | 1 | ### The term in use How the code actually writes about skylights and sloped glazing, quoted from the 2009 text hosted here: > Skylights and sloped glazing shall comply with the following sections. — [IRC 2009 §R308.6](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/building-planning.md) ## The terms skylights and sloped glazing is built out of The definition above leans on 1 other defined term. Each carries its own code definition, and a local amendment to any of them changes what skylights and sloped glazing covers: - **[Slope](https://harth.build/resources/glossary/slope.md)** — IRC 2009: The fall (pitch) of a line of pipe in reference to a horizontal plane. ## Skylights and Sloped Glazing: 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 IBC | Definitions | | | Read the definition in the adopted IRC | Building Planning | | | Re-check the requirement that uses it | Building Planning (IRC 2009) | | | Re-check the requirement that uses it | Roof Assemblies and Rooftop Structures (IBC 2009) | | | Re-check the requirement that uses it | Definitions (IBC 2009) | | | Confirm the dependent definition | Slope | | | 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) - [Slope: Building Code Definition](https://harth.build/resources/glossary/slope.md) - [Building: Building Code Definition](https://harth.build/resources/glossary/building.md) - [Construction Documents: Building Code Definition](https://harth.build/resources/glossary/construction-documents.md) - [Registered Design Professional: Building Code Definition](https://harth.build/resources/glossary/registered-design-professional.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 skylights and sloped glazing? The International Building Code (IBC) 2009 defines it in Definitions as: “Glass or other transparent or translucent glazing material installed at a slope of 15 degrees (0.26 rad) or more from vertical. Glazing material in skylights, including unit skylights, solariums, sunrooms, roofs and sloped walls, are included in this definition.” 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 skylights and sloped glazing? In this corpus the term is used across 3 chapters, led by Building Planning 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%2Fskylights-and-sloped-glazing%2F - View this page in a browser: https://harth.build/resources/glossary/skylights-and-sloped-glazing/ - All resources for agents: https://harth.build/llms.txt