The edifice located in Warsaw on the corner of Senacka and 10 Wiejska Street currently being in the possession of the Chancellery of the President of the Republic of Poland, was originally erected in the twentieth century between the two world wars as a seat of the Chamber of Industry and Commerce. The designer of the building, the famous and esteemed Warsaw architect - Zdzisław Mączeński, was selected as the result of a closed architectural competition in 1933. The building was constructed in two stages, in 1933-1934 and 1938-1939. Its architectural expression is a result of combining the “soft” functionalism of the 1930s with the radically reduced universal Classical forms and rules. The building reveals visible formal similarity to the official fascist architecture, which relished in accenting power and monumentality, and is a remarkable example of Monumental Classiczing Modernism, the so called “1937 Style” in Polish architecture. The study of the archive materials being in the possession of Z. Mączeński’s family enabled the author to determine the exact dates of the edifice’s construction process, which had previously been imprecise, and also allowed her to learn the circumstances and the chronology of the formation of the design’s documentation. Furthermore, numerous design drawings assembled in the family’s archive afforded an insight into the process of modelling the solid and the crystallization of the final architectural solutions.

Key words: Warsaw architecture of the first half of the 20th century, Zdzisław Mączeński, classic modernism, Chamber of Industry and Commerce in Warsaw