Modernization of buildings is necessary to provide for public housing needs. This term applies to structures and complexes which are not included in the register of monuments; yet it is associated with technical treatment and modernization processes in building complexes already recognized as historic. Work on the complexes that are of interest to conservators is often called the renewal of historic towns and complexes. The program has three parts: 1) modernization of utility functions of complexes and individual buildings, 2) stabilization of technical structures and development of infrastructure such as utilities, and 3) aesthetic arrangement of land structures and artistic elements. An interdisciplinary study should be prepared before all necessary town-planning and architecture designs are drawn. Examples of such complexes are illustrated. Twelve postulates aimed at improving the processes of programming, planning and executing the modernization and renewal works in Polish communities are presented.