Delaware building code

The residential code in Delaware is the International Residential Code, 2024 edition¹, effective January 1, 2026¹.

Last checked November 7, 2026

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Codes in force in Delaware
Scope, amendments and transition rules
How Delaware adopts building codes
Sources

Codes in force in Delaware

Each code family with the edition and the date it took effect, as the adopting agency or statute states them.

Code	Title as adopted	Model edition	Effective	Adopted by
Energy code, residential	Delaware Residential Building Energy Conservation Code²	2024²	April 11, 2026³	DNREC, Secretary’s Order No. 2026-CCE-0002³
Energy code, commercial	Delaware Commercial Building Energy Conservation Code²	2024²	April 11, 2026³	DNREC, Secretary’s Order No. 2026-CCE-0002³
International Plumbing Code (IPC)	2021 State of Delaware Plumbing Code⁴	2021⁴	August 11, 2022⁵	Delaware Division of Public Health⁴
International Mechanical Code (IMC)	2015 International Mechanical Code, as amended⁶	2015⁶	–	State Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners⁶
International Fuel Gas Code (IFGC)	2015 International Fuel Gas Code, as amended⁶	2015⁶	–	State Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners⁶
National Electrical Code (NEC)	NFPA 70, National Electrical Code, 2023⁷	2023⁷	January 1, 2026⁷	State Fire Prevention Commission⁸
International Fire Code (IFC)	NFPA 1, Fire Code, 2024⁷	2024⁷	January 1, 2026⁷	State Fire Prevention Commission⁸
State code	Delaware State Fire Prevention Regulations⁸	2024⁷	January 1, 2026⁷	State Fire Prevention Commission⁸
International Building Code (IBC)	International Building Code, 2024 edition¹	2024¹	January 1, 2026¹	New Castle County¹
International Residential Code (IRC)	International Residential Code, 2024 edition¹	2024¹	January 1, 2026¹	New Castle County¹
International Existing Building Code (IEBC)	International Existing Building Code, 2024 edition¹	2024¹	January 1, 2026¹	New Castle County¹
Swimming Pool and Spa Code (ISPSC)	International Swimming Pool and Spa Code, 2024 edition¹	2024¹	January 1, 2026¹	New Castle County¹
Energy code, residential	International Energy Conservation Code 2018¹	2018¹	January 1, 2021¹	New Castle County¹
International Mechanical Code (IMC)	International Mechanical Code, 2021 edition¹	2021¹	January 1, 2024¹	New Castle County¹
International Fuel Gas Code (IFGC)	International Fuel Gas Code, 2021 edition¹	2021¹	January 1, 2024¹	New Castle County¹
International Plumbing Code (IPC)	International Plumbing Code, 2021 edition¹	2021¹	January 1, 2024¹	New Castle County¹
International Building Code (IBC)	International Building Code 2018⁹	2018⁹	October 5, 2020⁹	Kent County Levy Court⁹
International Building Code (IBC)	2021 IBC¹⁰	2021¹⁰	January 1, 2023¹⁰	Sussex County¹⁰
International Residential Code (IRC)	International Residential Code 2018⁹	2018⁹	October 5, 2020⁹	Kent County Levy Court⁹
International Residential Code (IRC)	2021 IRC¹⁰	2021¹⁰	January 1, 2023¹⁰	Sussex County¹⁰

Scope, amendments and transition rules

Energy code, residential: Delaware Residential Building Energy Conservation Code

Scope: Statewide minimum; local governments may go further¹¹
Applies to: New detached 1- and 2-story family dwellings and other new residential buildings 3 stories or less¹¹
Local amendments allowed?: Yes¹¹
Amendments: 7 DE Admin. Code 2101²
Transition period: 12 months²

Energy code, commercial

Scope: Statewide minimum; local governments may go further¹¹
Amendments: 7 DE Admin. Code 2101²
Transition period: 12 months²

International Plumbing Code (IPC): 2021 State of Delaware Plumbing Code

Scope: Statewide; applies everywhere⁴
Local amendments allowed?: Additional local requirements allowed⁴
Amendments: 16 DE Admin. Code 4455⁴

International Mechanical Code (IMC): 2015 International Mechanical Code, as amended

Scope: Statewide; applies everywhere¹²
Local amendments allowed?: Proposed local changes go to the Board for review¹²
Amendments: 24 DE Admin. Code 1800 § 4.0⁶

International Fuel Gas Code (IFGC): 2015 International Fuel Gas Code, as amended

Scope: Statewide; applies everywhere¹²
Local amendments allowed?: Proposed local changes go to the Board for review¹²
Amendments: 24 DE Admin. Code 1800 § 4.0⁶

National Electrical Code (NEC)

Scope: Statewide; applies everywhere¹³

International Fire Code (IFC)

Scope: Statewide; applies everywhere¹³

State code

Scope: Statewide; applies everywhere¹³

International Building Code (IBC): International Building Code, 2024 edition

Scope: Adopted locally¹¹
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

International Residential Code (IRC): International Residential Code, 2024 edition

Scope: Adopted locally¹¹
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

International Existing Building Code (IEBC)

Scope: Adopted locally¹¹
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

Swimming Pool and Spa Code (ISPSC)

Scope: Adopted locally¹¹
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

Energy code, residential: International Energy Conservation Code 2018

Scope: Statewide minimum; local governments may go further¹¹
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

International Mechanical Code (IMC): International Mechanical Code, 2021 edition

Scope: Statewide; applies everywhere¹²
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

International Fuel Gas Code (IFGC): International Fuel Gas Code, 2021 edition

Scope: Statewide; applies everywhere¹²
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

International Plumbing Code (IPC): International Plumbing Code, 2021 edition

Scope: Statewide; applies everywhere⁴
Applies to: New Castle County outside municipalities¹⁴
Amendments: New Castle County Code Chapter 6¹

International Building Code (IBC): International Building Code 2018

Scope: Adopted locally¹¹
Applies to: Kent County outside municipalities with their own code¹⁵
Amendments: Amendments published by Kent County⁹

International Building Code (IBC): 2021 IBC

Scope: Adopted locally¹¹

International Residential Code (IRC): International Residential Code 2018

Scope: Adopted locally¹¹
Applies to: Kent County outside municipalities with their own code¹⁵
Amendments: Amendments published by Kent County⁹

International Residential Code (IRC): 2021 IRC

Scope: Adopted locally¹¹

How Delaware adopts building codes

16 Del. C. §§ 7601-7602; 24 Del. C. § 1806(c)-(d); 16 DE Admin. Code 4455; 1 DE Admin. Code 701

County building codes with state trade energy and fire codes. The Levy Court of Kent County and the County Councils of New Castle County and Sussex County may adopt and enforce building codes, plumbing codes, electrical codes or other similar codes.¹¹
2024 IECC. The Residential Provisions of the 2024 International Energy Conservation Code (IECC), published by the International Code Council, Inc., are hereby adopted with the following amendments as the Delaware Residential Building Energy Conservation Code, an enforceable part of the Delaware Building Codes.²
12 months. County and municipal building and plumbing codes shall meet all requirements of the applicable referenced code set forth in 7 DE Admin. Code 2101, Section 3.0 12 months after the date of promulgation, except as otherwise noted in 16 Del.C. §7602.²
Local plumbing enforcement required. Every political subdivision within the State, including county, city, or municipal governments, shall enforce the International Plumbing Code (IPC) as adopted or modified by the Division of Public Health.⁴
Local mechanical and fuel gas enforcement required. Every political subdivision within the State of Delaware, including county, city and municipal governments, shall enforce the International Mechanical Code (IMC) and the International Fuel Gas Code (IFC), as adopted or modified by the State Board of Plumbing, Heating, Air Conditioning, Ventilation and Refrigeration Examiners.¹²
Zero net energy capable mandate in statute. As of December 31, 2025, all new residential building construction in the State of Delaware shall be zero net energy capable.¹¹
DNREC deferred the zero net energy capable mandate. …the Department determined that implementation of these ZNE-capable provisions is not appropriate at this time.³
State fire regulations have force of law locally. Such regulations shall be in accordance with standard safe practice as embodied in widely recognized standards of good practice for fire prevention and fire protection and shall have the force and effect of law in the several counties, cities and political subdivisions of the State.¹³

Applies to: Three county governments¹¹
Can local rules be stricter?: Yes¹¹

For permits, exemptions and owner-builder rules, see Delaware building permits. To compare editions across states, see the code adoption map.

Sources

County Laws & CodeNew Castle County, DelawareChecked November 7, 2026
7 DE Admin. Code 2101, Regulations for State Energy Conservation CodeState of Delaware, Registrar of Regulations, Administrative CodePublished April 1, 2026Checked November 5, 2026
Secretary's Order No. 2026-CCE-0002State of Delaware, Department of Natural Resources and Environmental ControlAdopted March 10, 2026Checked November 5, 2026
16 DE Admin. Code 4455, Delaware Regulations Governing a Detailed Plumbing CodeState of Delaware, Registrar of Regulations, Administrative CodePublished August 1, 2022Checked November 7, 2026
26 DE Reg. 110 (08/01/22), Regulations Governing a Detailed Plumbing Code, final orderState of Delaware, Department of Health and Social Services, Division of Public HealthPublished August 1, 2022Checked November 5, 2026
24 DE Admin. Code 1800, Board of Plumbing, HVACR ExaminersState of Delaware, Registrar of Regulations, Administrative CodePublished April 1, 2026Checked November 7, 2026
1 DE Admin. Code 701, Administration and Enforcement (State Fire Prevention Regulations)State of Delaware, Registrar of Regulations, Administrative CodeEffective January 1, 2026Checked November 5, 2026
2026 Delaware State Fire Prevention Regulations update letterState of Delaware, Office of the State Fire MarshalPublished December 16, 2025Checked November 5, 2026
Permitting Requirements & Adopted CodesKent County Levy Court, DelawareChecked November 7, 2026
Building Code HistorySussex County, DelawareChecked November 5, 2026
16 Del. C. ch. 76, County or Municipal Building, Plumbing, Electrical and Other CodesState of Delaware, Delaware Code OnlineChecked November 5, 2026
24 Del. C. ch. 18, subch. I, Board of Plumbing, HVACR ExaminersState of Delaware, Delaware Code OnlineChecked November 5, 2026
16 Del. C. ch. 66, subch. I, State Fire Prevention CommissionState of Delaware, Delaware Code OnlineChecked November 5, 2026
9 Del. C. ch. 25, Building Code (New Castle County)State of Delaware, Delaware Code OnlineChecked November 7, 2026
9 Del. C. ch. 44, Building Permits and Construction Codes (Kent County)State of Delaware, Delaware Code OnlineChecked November 7, 2026