Delaware Building Code: Which Editions Are Adopted

Direct answer

No statewide building code; counties adopt their own, under a statewide 2024 IECC energy code effective 11 April 2026 in Delaware. State energy code (7 DE Admin. Code 2101) adopting the 2024 IECC for residential buildings and the 2024 IECC or ASHRAE 90.1-2022 for commercial buildings; the building and residential codes are adopted county by county. New Castle, Kent and Sussex counties, and municipalities with their own building departments, adopt and enforce the IBC and IRC at their own editions. They also enforce the state energy code. Fire safety is governed statewide by the Delaware State Fire Prevention Regulations, which are based on NFPA codes rather than the International Fire Code. This was checked on 2026-10-01 against Delaware Department of Natural Resources and Environmental Control (DNREC), 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 Delaware adopted now?

No statewide building code; counties adopt their own, under a statewide 2024 IECC energy code effective 11 April 2026.

State energy code (7 DE Admin. Code 2101) adopting the 2024 IECC for residential buildings and the 2024 IECC or ASHRAE 90.1-2022 for commercial buildings; the building and residential codes are adopted county by county.

Local adoption: New Castle, Kent and Sussex counties, and municipalities with their own building departments, adopt and enforce the IBC and IRC at their own editions. They also enforce the state energy code. Fire safety is governed statewide by the Delaware State Fire Prevention Regulations, which are based on NFPA codes rather than the International Fire Code.

Checked 2026-10-01 against Delaware Department of Natural Resources and Environmental Control (DNREC). 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 Delaware. Where this disagrees with the record above, the record above is newer:

Delaware has a recorded edition year for 4 of the 17 codes: 2021 for the mechanical, plumbing and fuel gas codes; 2018 for the residential energy code. The building, residential, private sewage, property maintenance, existing buildings, swimming pool and spa and green building standard codes appear as adopted by individual state or local agencies rather than as a statewide standard, so whether they apply depends on the permit jurisdiction for the project address. For the commercial energy code the chart records ASHRAE 90.1-2016 in place of an IECC edition. No adoption at all is recorded for the fire, green construction, performance, wildland-urban interface and zoning codes.

Source: ICC Master I-Code Adoption Chart (January 2024).

How Delaware 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.

Maryland, Pennsylvania, New Jersey and Virginia differ from Delaware on the building code alone. A practice working across that border is working to two editions, whatever the office standard says.

Where Delaware sits in the national record

Delaware is one of 17 jurisdictions with no statewide IBC edition in force. Adoption runs through local programmes or applies only to a subset of buildings, so there is no single answer for the state and the permit jurisdiction for the address decides.

Across all 17 codes the January 2024 ICC chart tracks, Delaware has a recorded edition for 4, which ranked it 43rd 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 Delaware project

1. Open Delaware Department of Natural Resources and Environmental Control (DNREC) 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.

Delaware 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
• Maryland Building Code: Which Editions Are Adopted
• Pennsylvania Building Code: Which Editions Are Adopted
• New Jersey Building Code: Which Editions Are Adopted
• Virginia 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 Delaware Department of Natural Resources and Environmental Control (DNREC), which controls.

Source links

• iccsafe.org

• iccsafe.org

• documents.dnrec.delaware.gov