Starting in 1880 he attended the architecture section of the Technischen Hochschule (now the Technical University of Vienna; Technische Universität Wien or TU-Wien), where his teachers included the historicist architects Karl König and Rudolf Weyr.

He graduated in 1887 and, in partnership with Philipp Herzog, won a competition for a residence building in Cottageviertel, a section of northwest Vienna in the Döbling and Währing districts that had been populated with mostly cottage-like single-family houses since the 1860s and 1870s.

In 1895 he was hired by the theater director Gabor Steiner to design Venedig in Wien ("Venice in Vienna"), one of the world's first theme parks, for which he was repeatedly called on to remodel pavilions whose purposes and amusements frequently changed.

In May 1901, the architect, acting as Secretary of the Actions Committee, traveled to Istanbul with Herzl and David Wolffsohn, Chairman of the Jewish Colonial Trust to meet the Sultan Abdul Hamid II.

In 1903 Marmorek took part in the El-Arisch Expedition, which investigated the suitability of the Sinai Peninsula for the purposes of Jewish settlement, though its recommendations turned out to be unfavorable; as a result, the British government offered an area in what is now Uganda as an alternative.

This led, however, to the split of the Zionist movement into the "Old" and "New" camps; the former wanted to seriously study the possibility of a Ugandan homeland and the latter categorically rejected any offer that did not absolutely consider territory in Palestine.