Analytical procedures are routinely used for structural integrity of buildings, but for moisture control, designers still rely on rules of thumb, such as “install vapor retarders in cold climates on the inside and in warm climates on the exterior of thermal insulation.” However, cold and warm climates are ill defined, large areas of the United States have warm summers and cold winters, and the rules do not recognize the effects of other materials in the thermal envelope. Analytical methods for determining the moisture movement in building envelopes are available. These methods can predict condensation, moisture content of layers and surface relative humidities; dynamic methods also predict the duration of moisture excursions, providing a basis for moisture damage risk assessment. Recognizing that practitioners are not generally trained to use available analytical tools, the Building Environment and Thermal Envelope Council (BETEC) has developed a tutorial on moisture analysis for building designers. The tutorial consists of a Moisture Primer, an Overview of Analysis Methods, and a training session on MOIST, a dynamic model developed by the National Institute for Standards and Technology. The paper outlines the need for the analytical approach to moisture control and summarizes the three sessions.