With that understanding established, we move to the best way to build the exterior walls of your home for avoiding moisture. There are two primary techniques, and I suggest both of them. The first is creating an air gap between the cladding (siding, stucco, brick, stone), and the second is insulating the exterior of your home as well. This is not in lieu of insulating the interior of the wall, but rather in addition to.  

Let’s start with insulating the exterior of your home. In this technique, we add insulation behind the cladding, which provides a buffer between the cold and warm air and helps to interrupt disruptive dewpoints. 

Zip System is the most commonly used product for exterior insulation, but there are others. It incorporates Polyiso Foam insulation, which is adhered to the OSB plywood. The green coating serves as a weather resistant barrier (WRB), which keeps moisture from reaching the plywood or interior wall space.

This building technique allows the air gap to provide a space for exterior air and Infiltrating moisture to escape out of the top and bottom of the wall. In the picture above, the air gap system would be attached to the green surface. 

Wall assemblies will change somewhat based on the climate zone in which you are building your home. For example, Florida is very different from Maine, or Colorado; while Maine is humid like Florida, it is much colder. Colorado is cold like Maine, but comparatively dry. Each climate zone will result in slight variations in wall assemblies and products.