Manufacturers and designers of energy efficient equipment might be well advised to check out Building Energy Codes 101: An Introduction. This guide is designed as a primer on the codes that apply to energy efficiency in buildings. The term “Building Energy Codes” is used as a generic term that includes ASHRAE 90.1 (a standard), the IECC (a code), and other forms of building energy standards, guidelines, laws, rules, etc. that are part of the larger body of building codes and must be satisfied as a condition for approval to construct and occupy buildings.
Two primary baseline building energy codes may be adopted by states and local jurisdictions to regulate the design and construction of new buildings: the International Energy Conservation Code (IECC), and the ANSI/ASHRAE/IESNA Standard 90.1 Energy Standard for Buildings except Low-Rise Residential Buildings. The IECC addresses all residential and commercial buildings. ASHRAE 90.1 covers commercial buildings, defined as buildings other than single-family dwellings and multi-family buildings three stories or less above grade.
The IECC is revised every three years per a well-defined revision process, which this primer also covers.
You can download a copy of the PDF here: