The paper presents the renovation process of the shaft mining building No. 2 situated in the Kłodawa Salt Mine. A technical state of the facility required immediate reinforcement of structural elements, which was confirmed by expertise carried out by the authors. A lack of repairs could be the cause of building damage. The progress of corrosion in some steel profiles of columns or floors was very advanced. The state of the building was rapidly worsening due to the very high salinity of the indoor environment, moisture (building not insulated) and vibrating engines of machinery operating on different floors felt throughout the facility. After carrying out the technical expertise, working plans and specifications, and relevant numerical analysis, the modernization process was realized by the reinforcement or rebuilding of structural elements.