The International Energy Conservation Code (IECC) is a building code created by the International Code Council in 2000. It is a model code adopted by many states and municipal governments in the United States for the establishment of minimum design and construction requirements for energy efficiency.[1] [2] The code is updated every 3 years, to provide an ongoing standard of best practices for energy efficiency.[3]
In addition to overall building standards the code defines the Climate Zones used in building, shown in this picture. These should not be confused with the USDA plant Hardiness zone.