From coastal regions battered by heavy rain to dry, less severe climates, moisture management solutions-variously called water resistive barriers, housewraps, and rainscreen systems-increasingly are being viewed as essential components to well-constructed sidewall systems. Spurred by technological advances in these building products, homebuilders, architects, and contractors alike are specifying them to protect residential wall assemblies from potential mold and mildew damage and to improve heating and cooling efficiency.