This report is a guide for the design of flexural concrete members in buildings post-tensioned with unbonded tendons. Suggestions for revisions and additions to ACI 318 regarding this subject are presented. Consideration is given to determination of fire endurance, design for seismic forces, and design for catastrophic loadings, in addition to design for gravity and lateral loads. Recommendations concerning details and properties of tendons, protection against corrosion, and construction procedures are presented.