Are you interested in purchasing a quality home or townhouse in Illinois? Or want to learn more about how to make your existing home more energy-efficient? This guide provides a quick way to assess home energy performance. The guide describes the minimum standards of construction practice for new homes in Illinois based on the 2012 International Energy Conservation Code (IECC) with amendments as the Illinois Energy Conservation Code. While it does not include every requirement, this will help you assess your own home, and if you are in the market for a new home, make an informed decision about the quality of construction and efficiency for that new home purchase.