The issue conservation of ruins is highly actual in the present as a wave of ruin conservation and restoration has been proceeding in Slovakia since 2006. The issue brings out a problem of a proper roof over ruins for various functions (background, museum etc.) by its method and expression. A dissertation thesis focuses in its first part on development and actual trend of shelters and enclosure buildings in Europe and Slovakia. A theoretical part presents the issue roofs over ruins with its characteristics (a scale of volume preservation, a scale of burying, climate conditions, a stability of a ruin after its consolidation etc.), that set limits/determinants for an architect – project engineer and his creative work with the ruin and the shelter or the enclosure building over it. The chapter include also methods of monument conservation and restoration and a new shape applied in influencing a shape of shelters and enclosure buildings over ruins of architecture. In other part there is described an administrative process of approval and professions entering a process of the ruin conservation and a design of the new covering structure. Researched knowledge is practically applied at archaeological site –The Old Town on the Hill Glanzenberg in Banská Štiavnica using a method of a research by architectural design. In conclusion, results are summed up in principles/recommendations that can be useful for setting a conservation concept, methodists and project engineers of a new covering construction. To illustrate the design process of the enclosure building, a studio project of students on the archeological site The Grave Mound in Očkov is in attachment A.