The paper discusses radon prevention in the design and construction of schools and other large buildings. The U.S. EPA's Office of Research and Development (ORD) has started incorporating radon control measures into the design and construction of new schools and other large buildings. The goal of the new designs is twofold: (1) to prevent elevated radon levels in the completed building, and (2) to provide the protection at a fraction of the cost of retrofit systems. ORD's Air and Energy Engineering Research Laboratory (AEERL) has conducted the research necessary to develop viable designs. The Indoor Radon Abatement Act of 1988 set a national long-term goal for indoor radon of 0.5 picocurie per liter (pCi/L)--the same as that typically found in outdoor air. The EPA currently recommends that homeowners take action to reduce radon levels to below 4 pCi/L. To achieve the national goal set in the 1988 Act for new construction in radon-prone areas, AEERL research is using a combination of active subslab depressurization (ASD) and operation of the heating, ventilation, and air-conditioning (HVAC) system to pressurize buildings. These measures are described briefly, along with a case history of one building.