Building Energy Code

June 18, 2023


NOTE: Much of the information presented in this summary is drawn from the U.S. Department of Energy’s (DOE) Building Energy Codes Program and the Building Codes Assistance Project (BCAP). For more detailed information about building energy codes, visit the DOE and BCAP websites.

On May 2014, Delaware updated its energy code to 2012 IECC with amendments for residential sector and ASHRAE 90.1-2010 with amendments for the commercial sector. The Delaware specific amendments to the energy code can be accessed on the regulation webpage. These codes are effective starting November 2014 following a six month grace period. 

The Delaware Energy Code is reviewed by the State Energy Office every three years for potential updates to the most recent version of the International Energy Conservation Code (IECC) and ASHRAE Standard 90.1. The compliance with the building code is mandatory statewide, with exception for agricultural structures as determined by the local government. The codes are enforced on the local level by the code officials within the county or municipality. 

SB 59, signed in July of 2009 requires the Delaware Energy office to establish programs to promote construction of zero net energy homes. The law requires all new residential buildings constructed after December 31, 2025, and all new commercial buildings constructed after December 31, 2030 to be zero net energy capable. To be qualified as net zero energy capable, the building must be energy efficient enough that the building would consume zero energy if the building owner chose to install on-site generation.

In June 2020, the Division amended the Regulations by adopting the 2018 International Energy Conservation Code and the ASHRAE 90.1 2016 Energy Standard for Buildings Except Low Rise Residential Buildings. These codes become effective on December 11, 2020.

Program Overview

Implementing Sector: State
Category: Regulatory Policy
State: Delaware
Incentive Type: Building Energy Code
Web Site:
Administrator: Delaware Department of Natural Resources
Start Date:
Eligible Renewable/Other Technologies:
  • Comprehensive Measures/Whole Building
Residential Code: 2018 IECC; may use REScheck or ENERGY STAR documentation software to show compliance
Commercial Code: ASHRAE Standard 90.1-2010 with amendments; may use COMcheck to show compliance
Code Change Cycle: Every three years
Jurisdictions: Mandatory statewide


Name: 16 Del. C. § 7602)
Effective Date: 07/01/2010


Name: Crystal Nagyiski
Organization: Delaware Department of Natural Resources and
Address: 1203 College Park Dr, Suite 101
Dover DE 19903
Phone: (302) 735-3480

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.