A joint initiative among the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the International Code Council (ICC), the American Institute of Architects (AIA), the Illuminating Engineering Society (IES) and the U.S. Green Building Council (USGBC) is working toward unifying ASHRAE's Standard 189.1 for High Performance Green Buildings with ICC's International Green Construction Code (IgCC) into one single model code. This integrated document, known as the "IgCC powered by 189.1," will become the 2018 IgCC and is due to be published in Summer 2018. The goal is to provide regulatory requirements to energy efficiency, resource conservation, water safety, land use, site development, indoor environmental quality and building performance that can be adopted by local jurisdictions.

Once the technical content of the 2018-IgCC is known, the USGBC will then analyze the measures from the model green code and compare them to LEED requirements. This process will begin while the 2018-IgCC is being codified. The USGBC anticipates being able to communicate further progress on alignment at Greenbuild, to be held in Boston from November 8-10.