This article presents the result of a scientific analysis on the interior design of the restoration process of two important buildings in the history of national architecture: the Organ Hall and the National Museum of Art of Moldova. In this context, the interior design has assumed major responsibilities in respecting the stylistic elements according to the historical preferences, aiming primarily at preserving and capitalizing on the national cultural heritage. At the same time, the interior design project involves modern solutions in technical engineering and security procedures, so as to provide the interior spaces with optimal operating conditions without diminishing the aesthetic reminiscences of the past. The success of the renovation and restoration of the interior design is largely due to the principles of plastic approach to the project.