Energy Efficiency Policies and Practices in Illinois

Residential and Commercial Sectors

Residential and commercial buildings account for 40% of energy use in the country.  These buildings where we live and work are affected by policies that provide minimum construction standards that reduce energy waste, provide financing options to help pay for energy upgrades, promote advancing energy efficiency through high-performance buildings that go beyond minimum requirements and techniques for taking advantage of the latest technologies in energy monitoring and control, and that ensure that as buildings become tighter that the health and safety of occupants are maintained.

Building Energy Codes in Illinois

Code Level

Residential Energy Code

2015 IECC (effective 1/1/2016)

The Illinois Energy Conservation Code

Commercial Energy Code

2015 IECC (effective 1/1/2016)

The Illinois Energy Conservation Code


Authorized by Statute. 2009's Energy Efficient Buildings Act, (HB 3987) modified the previous "Energy Efficient Commercial Buildings Act" to require the latest version of the International Energy Conservation Code as the building energy code for both commercial and residential buildings. The statute is found at 20 ILCS 3125.  Administrative rules for the Illinois Energy Conservation Code are found at 71 IAC 600.

Oversight – The building codes, including the energy code, are overseen by the Capital Development Board, and more specifically by the CDB's Division of Building Codes & Regulations. The Illinois Energy Code Advisory Council meets regularly to evaluate energy code issues and provide advice to the Board.

Code change process – Regulatory and Legislative. The Capital Development Board reviews and adopts the latest model code (within a year of its release, 20 ILCS 3125/20(a)). The rule adopting the new code must then be approved by the General Assembly's Joint Committee on Administrative Rules (JCAR).

Code change cycle – Every 3 years, when new model codes are published by the IECC.


Enforcement The Capital Development Board, along with the Department of Commerce and Economic Opportunity are responsible for defining compliance procedures (20 ILCS 3125/30). Code enforcement is the duty of the local jurisdiction, who must meet minimum compliance documentation requirements as defined by the administrative rules in 71 IAC 600.

Implementation/Compliance Studies – The Building Codes Awareness Project (BCAP) has details on current efforts to measure Illinois' code compliance and to provide recommendations for achieving 90% compliance.  These efforts include analysis by BCAP and a DOE-funded compliance study.

► Overview of building energy codes in the Midwest

Home Performance

In addition to building energy codes, states and utilities are often looking for ways to take buildings "beyond code" and achieve higher levels of energy savings. Home performance programs are becoming widespread in the region and offer a good best-practices example of a next step beyond baseline building energy code for states and utilities that are interested in achieving additional energy savings in residential buildings.

Summary of Home Peformance Programs in Illinois
  Administrator Program Audit Fee Maximum Customer Benefit
Illinois Ameren Illinois Act on Energy - Home Energy Performance $25 Up to $2,400 based on EE measures deployed
IL DCEO Illinois Home Performance with Energy Star Market-based Varies, combined with other programs
ComEd & Nicor Gas Home Energy Savings Program $49 Instant rebates of 70% up to $1,750

► Overview of home performance programs in the Midwest


Read the report that accompanies these pages:
Energy Efficiency Policies, Programs, and Practices in the Midwest:
A Resource Guide for Policymakers (2014 Edition)

►more information about the Resource Guide