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.