From 1904 on, he was able to carry out big projects; the most notable the so-called "Loos House" (built from 1910–12), originally the Viennese tailor Goldman and Salatsch, for whom Loos had designed a store interior in 1898, and situated right across from the Habsburg city residence Hofburg Palace. The house, today Michaelerplatz 3, Vienna, and under monument preservation, was criticized by its contemporaries. The facade was dominated by rectilinear window patterns and a lack of stucco decoration and awnings, which earned it the nickname "House without Eyebrows"; Emperor Franz Joseph I of Austria was said to have despised the modern building so much that he avoided leaving the Hofburg Palace through a main gate in its vicinity.[5] His work also includes the store of the men's fashion house Knize (built 1909–13), Am Graben 13, Café Museum (built 1899), Operngasse 7, Vienna, and the "American Bar" (built 1907–08), Kärntnerstrasse 10, Vienna.[6]
Loos visited the island of Skyros in 1904 and was influenced by the cubic architecture of the Greek islands. When the Austro-Hungarian Empire collapsed after World War I Loos was awarded Czechoslovakian citizenship by President Masaryk.[2] His main place of residence remained in Vienna. During the First Austrian Republic Loos became interested in public projects. He designed several housing projects for the City of Vienna (Red Vienna). From 1924–28 Loos lived in Paris. He taught at the Sorbonne and was contracted to build a house for Tristan Tzara, which was completed 1925 in Avenue Junot 15, Paris. In 1928 he returned to Vienna.