# Connecticut Building Code: Which Editions Are Adopted > Which I-Code editions Connecticut is recorded as adopting, what the record does not cover, and how to confirm the edition governing a project. - Canonical: https://harth.build/resources/code-adoption/connecticut-building-code-adoption/ - Last updated: 2026-09-07 - Data source: Adopted editions transcribed from the [ICC Master I-Code Adoption Chart (January 2024)](https://www.iccsafe.org/wp-content/uploads/Master-I-Code-Adoption-Chart-1.pdf), reproduced with the chart's own legend so an “X” is not mistaken for a statewide adoption. ICC notes that not all jurisdictions report their adoptions and publishes updates at [iccsafe.org/adoptions](https://www.iccsafe.org/adoptions). The current edition, its effective date and the state amendments are published by [Connecticut's official building-code publication](https://portal.ct.gov/DAS/Office-of-State-Building-Inspector/Connecticut-State-Building-Code/Regulations), which controls. ## Key facts | Fact | Value | | --- | --- | | Current adoption | 2022 Connecticut State Building Code, effective 1 October 2022 (checked 2026-09-08 against Connecticut Office of the State Building Inspector) | | Building | 2021 IBC portion of the 2022 Connecticut State Building Code (as published by the authority named below) | | Existing buildings | 2021 IEBC portion of the 2022 Connecticut State Building Code (as published by the authority named below) | | Cross-state chart record | 2021 IBC (ICC chart, January 2024 — older than the record above) | ## Direct answer 2022 Connecticut State Building Code, effective 1 October 2022 in Connecticut. 2021 IBC and 2021 IEBC with a Connecticut state supplement and amendments. This was checked on 2026-09-08 against Connecticut Office of the State Building Inspector, which is the source that controls. Record the permit application date with it: a code change normally applies from an effective date, and an application filed before that date is usually reviewed under the previous edition. Local amendments sit on top of the state adoption and can change a requirement without changing the edition, so read the adopting ordinance for the permit jurisdiction alongside the state text. The cross-state comparison further down this page comes from the ICC adoption chart dated January 2024, so where the two disagree the record above is the newer one. *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.* ![Code-adoption status diagram: Connecticut Building Code: Which Editions Are Adopted](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/code-adoption/connecticut-building-code-adoption/diagram-1344.webp) *Which I-Code editions Connecticut is recorded as adopting, what the record does not cover, and how to confirm the edition governing a project.* ## What must be verified before using this guidance? **2022 Connecticut State Building Code, effective 1 October 2022.** 2021 IBC and 2021 IEBC with a Connecticut state supplement and amendments. | Discipline | Adopted | | --- | --- | | Building | 2021 IBC portion of the 2022 Connecticut State Building Code | | Existing buildings | 2021 IEBC portion of the 2022 Connecticut State Building Code | Checked 2026-09-08 against [Connecticut Office of the State Building Inspector](https://portal.ct.gov/DAS/Office-of-State-Building-Inspector/Connecticut-State-Building-Code/Regulations). Confirm the edition and effective date for the specific permit jurisdiction before relying on it. ## The cross-state record For comparison across states, every I-Code the ICC Master I-Code Adoption Chart (January 2024) tracks, as it records Connecticut. Where this disagrees with the record above, the record above is newer: | Code | Recorded adoption | | --- | --- | | International Building Code (IBC) | 2021 | | International Residential Code (IRC) | 2021 | | International Fire Code (IFC) | 2021 | | International Mechanical Code (IMC) | 2021 | | International Plumbing Code (IPC) | 2021 | | International Private Sewage Disposal Code (IPSDC) | Not adopted | | International Fuel Gas Code (IFGC) | Not adopted | | International Green Construction Code (IgCC) | Not adopted | | International Energy Conservation Code — Residential (IECC-R) | 2021 | | International Energy Conservation Code — Commercial (IECC-C) | 2021 | | International Property Maintenance Code (IPMC) | Not adopted | | International Existing Building Code (IEBC) | 2021 | | International Swimming Pool and Spa Code (ISPSC) | 2021 | | ICC Performance Code (ICCPC) | Not adopted | | International Wildland-Urban Interface Code (IWUIC) | Not adopted | | International Zoning Code (IZC) | Not adopted | | ICC 700 National Green Building Standard (ICC 700) | Not adopted | Connecticut has a recorded edition year for 9 of the 17 codes: 2021 for the building, residential, fire, mechanical, plumbing, residential energy, commercial energy, existing buildings and swimming pool and spa codes. No adoption at all is recorded for the private sewage, fuel gas, green construction, property maintenance, performance, wildland-urban interface, zoning and green building standard codes. Source: [ICC Master I-Code Adoption Chart (January 2024)](https://www.iccsafe.org/wp-content/uploads/Master-I-Code-Adoption-Chart-1.pdf). ## How Connecticut compares with its neighbours | State | Building (IBC) | Residential (IRC) | Residential energy (IECC-R) | | --- | --- | --- | --- | | **Connecticut** | 2021 | 2021 | 2021 | | Massachusetts | 2015 | 2015 | 2021, as a stretch code only | | Rhode Island | 2018 | 2018 | 2018 | | New York | 2018 | 2018 | 2018 | | New Jersey | 2021 | 2021 | 2021 | Massachusetts, Rhode Island and New York differ from Connecticut on the building code alone. A practice working across that border is working to two editions, whatever the office standard says. ## Where Connecticut sits in the national record Of the 50 states and the District of Columbia, **18 are recorded on the 2021 IBC**, 0 on a later edition, 26 on an earlier one, and 7 with no statewide IBC edition at all. Connecticut is at or ahead of the national middle on the building code, so the risk runs the other way: work arriving from a slower-moving state may be drawn to an older edition. The building code and the residential energy code are on the same 2021 edition here. That is convenient but not a rule — the two are adopted under separate processes and can diverge at the next cycle. Across all 17 codes the chart tracks, Connecticut has a recorded edition for **9**, which ranks it 12th of 51. A low count is not a gap in regulation — it usually means the state legislates through its own documents, or leaves the discipline to local adoption. ## What the chart does and does not tell you The chart's own legend matters more than the numbers: - **An edition year** means one or more state or local agencies adopted that edition. It does not mean every building in the state is designed to it. - **“Some jurisdictions only”** is the chart's `X`: the code is in use somewhere in the state but is not the standard for all buildings. - **“Not adopted”** is a blank cell — no state or local jurisdiction reported adopting that code. - **“State-written code”** means the state publishes its own document in place of the model edition, so the model text is a reference, not the law. ICC states plainly that not every jurisdiction notifies it of an adoption, and this chart is dated **January 2024**. Treat it as the starting point for a search, never as the answer. ## How to confirm the edition that governs a Connecticut project 1. Open [Connecticut's official building-code publication](https://portal.ct.gov/DAS/Office-of-State-Building-Inspector/Connecticut-State-Building-Code/Regulations) and find the currently adopted code list with its effective date. 2. Check whether the permit authority for the project address is the state or a local programme with its own adoption. 3. Read the state amendments alongside the model edition — an amended table or definition changes the requirement even when the edition matches. 4. Record the permit application date. A code change usually applies from an effective date, and applications filed before it are normally reviewed under the previous edition. 5. Get the answer in writing from the authority having jurisdiction before it drives a design decision. ## Connecticut code-basis worksheet Fill this in once per project and keep it with the drawing set. Every row is a question a plan reviewer can ask, and the answer changes with the address and the application date, not with the state. | Item | Project entry | | --- | --- | | Project address and permit jurisdiction | | | State programme or local programme as AHJ | | | Building / residential edition and effective date | | | Energy code edition (or state-written code) | | | Fire, mechanical, plumbing and fuel-gas editions | | | Accessibility standard and edition | | | State amendments consulted (citation) | | | Local amendments consulted (citation) | | | Permit application date and vesting rule | | | Written AHJ confirmation (date, name) | | **This worksheet records a determination; it does not make one.** The authority having jurisdiction decides which edition and which amendments apply. ## Where can you explore related guidance? - [Explore all code adoption guidance](https://harth.build/resources/code-adoption.md) - [Massachusetts Building Code: Which Editions Are Adopted](https://harth.build/resources/code-adoption/massachusetts-building-code-adoption.md) - [Rhode Island Building Code: Which Editions Are Adopted](https://harth.build/resources/code-adoption/rhode-island-building-code-adoption.md) - [New York Building Code: Which Editions Are Adopted](https://harth.build/resources/code-adoption/new-york-building-code-adoption.md) - [New Jersey Building Code: Which Editions Are Adopted](https://harth.build/resources/code-adoption/new-jersey-building-code-adoption.md) ## Sources and method Adopted editions transcribed from the [ICC Master I-Code Adoption Chart (January 2024)](https://www.iccsafe.org/wp-content/uploads/Master-I-Code-Adoption-Chart-1.pdf), reproduced with the chart's own legend so an “X” is not mistaken for a statewide adoption. ICC notes that not all jurisdictions report their adoptions and publishes updates at [iccsafe.org/adoptions](https://www.iccsafe.org/adoptions). The current edition, its effective date and the state amendments are published by [Connecticut's official building-code publication](https://portal.ct.gov/DAS/Office-of-State-Building-Inspector/Connecticut-State-Building-Code/Regulations), which controls. ### Source links - [iccsafe.org](https://www.iccsafe.org/wp-content/uploads/Master-I-Code-Adoption-Chart-1.pdf) - [iccsafe.org](https://www.iccsafe.org/adoptions) - [portal.ct.gov](https://portal.ct.gov/DAS/Office-of-State-Building-Inspector/Connecticut-State-Building-Code/Regulations) ## Frequently asked questions ### Which building code edition does Connecticut use? The ICC Master I-Code Adoption Chart (January 2024) records Connecticut on the 2021 International Building Code. That is the edition ICC was told about; the effective date, the amendments and any newer adoption live with Connecticut's official building-code publication, which is the source to check before relying on it. ### Why does this page not simply state today's code? Because the underlying record is dated. The ICC Master I-Code Adoption Chart (January 2024) is the most complete cross-state source available, and ICC notes that not every jurisdiction reports its adoptions. Publishing it with its date attached and sending you to Connecticut's official building-code publication is honest; publishing an undated “current edition” would not be. --- - Continue in Harth (open this topic in the Harth agent): https://app.harth.build/agent?context=%2Fresources%2Fcode-adoption%2Fconnecticut-building-code-adoption%2F - View this page in a browser: https://harth.build/resources/code-adoption/connecticut-building-code-adoption/ - All resources for agents: https://harth.build/llms.txt