Two Twenty Apartments was a window and siding replacement project that used 5,000 sq. ft. of WrapShield RS Rain Screen Water Resistive Vapor Permeable Air Barrier with Built-In Rain Screen Drainage Matrix.The old lap siding was removed, the rot was repaired, and WRAPSHIELD RS™ RAIN SCREEN was installed as a water resistive barrier (WRB) and air barrier (AB) to prevent bulk water infiltration and reduce energy. With one step rain screen cavity installation, WRAPSHIELD RS™ RAIN SCREEN reduced installation time and labor costs, thereby saving $1.00 per sq. ft. on the installation versus the typical batten rain screen system.Rain screen design is a twofold approach used to control rain penetration into interior walls. The first line of defense, the exterior cladding, minimizes rain passage by blocking leaks. The second defense, WRAPSHIELD RS™ RAIN SCREEN, intercepts all water allowing it to drain to the exterior.WRAPSHIELD RS™ RAIN SCREEN's air barrier design reduces energy consumption by as much as 40% per year over the life of the building, providing a significant cost savings to residents of this multi-family apartment building.