On September 15 the Illinois Climate and Equitable Jobs Act (CEJA) was signed into law. The bill contains many energy efficiency components that will impact and improve the lives of citizens and workers in Illinois, including a provision to create a state stretch energy code.

What is a Stretch Code?

A stretch code defines a higher level of energy efficiency or sustainability for new construction than the applicable energy code. Depending on local laws, stretch codes may be developed on their own (typically by/for municipalities) or as part of the larger state energy code (either as a separate state stretch code or in an optional appendix). Once a stretch code is adopted by a jurisdiction, it becomes the mandatory energy code for that jurisdiction. However, not all states or municipalities have the ability to create or adopt stretch codes.

Stretch Codes in the Bill

(pages 237; 244-248; 630) 

The bill language enables municipalities to improve on the state building energy code and require greater energy efficiency at the time of building construction. The bill directs the Illinois Capital Development Board (CDB), which manages the state building energy code adoption process, to create a residential and commercial stretch energy code that can be adopted by individual municipalities. The bill requires the stretch code to meet a set of specific “site energy index” performance targets that include “only conservation measures and excludes net energy credit for any on-site or off-site energy production.” The bill also sets targets that increase the energy efficiency of the stretch code every three years, ensuring the stretch code will always be more efficient than the state’s base energy code. Once formally adopted by a municipality, the stretch code takes the place of the state energy code and establishes the minimum energy efficiency requirements for new construction, additions, and major renovations.

The bill also allows for an alternative compliance path for the stretch code through "project certification by a nationally recognized nonprofit certification organization specializing in high-performance passive buildings and offering climate-specific building energy standards that require equal or better energy performance than the Illinois Stretch Energy Code." One such example would be the Passive House Institute – US (PHIUS) standard.

Also included in the bill is a provision allowing utilities to engage in compliance-related education and programming that can count toward their energy savings goals.

Energy Efficiency Improvement Goals

The site energy indices for the new Illinois stretch code are outlined in the tables below. A site energy index is essentially the relationship of any energy code to the 2006 IECC, as calculated and defined by the Pacific Northwest National Laboratory (PNNL). With this system, a score of 1.0 is equal to the 2006 IECC/ASHRAE 90.1-2004, and scores that are lower than 1.0 consume less energy than the 2006 IECC/ASHRAE 90.1-2004. The residential 2021 IECC is estimated to be around 40% more efficient than the 2006 IECC, giving it a score of 0.60. According to the Pacific Northwest National Laboratory (PNNL), the current energy code in Illinois has a site energy index of 0.76 for residential and 0.66 for commercial. Using those numbers to meet the stretch code initial targets, the residential stretch code would need to improve in energy efficiency by 34.2% and the commercial stretch code by 9.1% compared to the current Illinois energy code. The bill language specifically calls out that these targets must be met by conservation measures only, and “excludes net energy credit for any on-site or off-site energy production.”

Residential Targets

*If “unanticipated burdens” are associated with previous stretch code, new code must be at least 58% more efficient than 2006 IECC and at least 5% better than 2024 IECC

** If “unanticipated burdens” are associated with previous stretch code, new code must be at least 65% more efficient than 2006 IECC; and at least 5% better than 2027 IECC

Commercial Targets