Energy codes govern how much energy a building is allowed to consume, and they directly shape design decisions from the earliest schematic phases. Two dominant frameworks set the rules for most projects in the United States: the International Energy Conservation Code (IECC) and ANSI/ASHRAE/IES Standard 90.1. The IECC applies broadly to both residential and commercial buildings, while ASHRAE 90.1 focuses specifically on commercial and high-rise residential construction.

For the ARE, you need to know the compliance paths these codes offer and how each one affects design. The prescriptive path spells out exact requirements for insulation R-values, fenestration U-factors, lighting power density, and equipment efficiency. The performance path gives designers more freedom by allowing tradeoffs between building systems, as long as the proposed design uses no more annual energy than a code-compliant baseline. There is also an envelope tradeoff approach that permits exchanges specifically within the building skin, such as adding more roof insulation to offset larger window areas.

Climate zones drive the specific numeric thresholds for each requirement. The IECC divides the country into eight temperature zones with moisture sub-designations (A, B, or C), and those zones set everything from minimum wall insulation to maximum solar heat gain coefficients for glazing. Getting the compliance path right early in design keeps the project on budget and on schedule, so understanding these frameworks is a core skill NCARB expects you to demonstrate.