The document presented below derives, with a few revisions to clarify the meaning in the context of the book, from the research report delivered to the clients of the Asian Development Bank and the Urban Development Committee of the Armenian Government. It consists of guidelines for the maintenance of historic buildings intended mainly for inhabitants and unskilled workers. The choice to propose them maintaining both the simple language and the graphic layout that distinguished the document delivered, is motivated by the intention to propose them as possible methodological tools addressing the theme of the existing city in emerging contexts. Although specifically designed for the city of Gyumri and not exportable uncritically to other realities, they may suggest methods to sensitize the inhabitants to the fact that they live in a cultural heritage intended as a complex formed by the city and its individual buildings. The awareness of the uniqueness and irreproducibility of this Heritage implies, consequently, a more respectful intervention in existing buildings. In contexts where self-construction also concerns the architectural heritage, easy indications are necessary to carry out the necessary interventions to provide the buildings with greater living comfort.