The paper addresses matters that must be considered in planning a new jail or evaluating an existing one. Architectural requirements are discussed for the following jail areas and activities: area for reception and booking; living areas; windows; noise; cells, lighting, and heating and cooling; program support areas; exterior area; classification plan; programs; visiting; telephone privileges; freedom of expression within the facility; freedom of religion; exercise and recreation; general library; and sanitation. The concluding section provides a detailed examination of building costs. The high unit costs associated with traditional and now unconstitutional over-reliance on hardware and security controls are contrasted with the unit costs for the kinds of construction called for by contemporary approaches.