Climate Regions
Introduction
In design and construction, while figuring out the building technology that may be used — the most important factor to start with is the climate region of the area. Building science, energy code, and residential design in general is greatly influenced and referenced to these climate zones. They also control specifics such as where to locate (if any) vapor barrier in a wall assembly. Understanding these 8 climate zones is imperative to implementing best practices and creating an efficient and performing design.
Varying Definitions
There are many different organizations and governing bodies that have produced many different definitions. This page organizes and categorizes (generally and roughly speaking) what Architects need to know in the US for energy code and building technology.
Classification International Energy Conservation Code (IECC) & Pacific Northwest National Laboratory (PNNL)
In the early 2000s, the PNNL made an effort to categorize and simplify climate zone definitions so that all the various groups could come to a consensus and refer to the same map when dictating energy code and requirements. This map was based on weather readings from almost 5,000 weather stations, and is now widely used and published as part of the IECC.
This simplified map identified 8 temperature oriented climate zones, as well as being able to identify each zone as 3 separate climate regimes. Together, this creates the theoretic ability for 24 different designations (8 * 3 = 24) — In reality not all definitions are used.