Connecticut Building Code: Which Editions Are Adopted

Direct answer

2022 Connecticut State Building Code, effective 1 October 2022 in Connecticut. 2021 IBC, IRC, IECC, IEBC, IMC, IPC and ISPSC plus the 2020 NEC, with Connecticut amendments. A 2026 Connecticut State Building Code based on the 2024 I-Codes and the 2023 NEC was expected to take effect on 1 July 2026. It is still awaiting approval by the General Assembly's Legislative Regulation Review Committee, so the effective date has been delayed and the 2022 code remains in force. 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. This was checked on 2026-10-01 against Connecticut Office of the State Building Inspector, which is the source that controls. 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 Harth team · Published 2026-09-07 · Updated 2026-10-01.

Which codes has Connecticut adopted now?

2022 Connecticut State Building Code, effective 1 October 2022.

2021 IBC, IRC, IECC, IEBC, IMC, IPC and ISPSC plus the 2020 NEC, with Connecticut amendments.

Transition: A 2026 Connecticut State Building Code based on the 2024 I-Codes and the 2023 NEC was expected to take effect on 1 July 2026. It is still awaiting approval by the General Assembly's Legislative Regulation Review Committee, so the effective date has been delayed and the 2022 code remains in force.

Checked 2026-10-01 against Connecticut Office of the State Building Inspector. 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:

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).

How Connecticut compares with its neighbours

Statewide editions in force, checked 2026-10-01; “Local” means no state adoption, “(limited)” a state adoption for some buildings only, and * a state-titled code built on that edition.

Rhode Island, New York and New Jersey 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, 17 enforce the 2021 IBC statewide, 10 a later edition, 7 an earlier one, and 17 have no statewide IBC edition in force. 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.

Across all 17 codes the January 2024 ICC chart tracks, Connecticut has a recorded edition for 9, which ranked 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 Office of the State Building Inspector 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.

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
• Massachusetts Building Code: Which Editions Are Adopted
• Rhode Island Building Code: Which Editions Are Adopted
• New York Building Code: Which Editions Are Adopted
• New Jersey Building Code: Which Editions Are Adopted

Sources and method

Adopted editions transcribed from the ICC Master I-Code Adoption Chart (January 2024), 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. The current edition, its effective date and the state amendments are published by Connecticut Office of the State Building Inspector, which controls.

Source links

• iccsafe.org

• iccsafe.org

• portal.ct.gov