As a consequence, he returned to Lviv and worked as professor at the academy and was appointed dean of the Faculty of Civil Engineering.

In 1877, he received the "Ritter" title of Austrian nobility (Grade II) with the predicate "von Lwigród".

The main building of the polytechnic, known as the "Mother of Polish Technical Universities", was designed in the eclectic Neo-Renaissance style that was fashionable at the time.

Zachariewicz made a number of journeys across Germany and Austria before designing the polytechnic, in order to familiarise himself with the newest innovations relating to the construction of this type of building.

He also designed numerous public buildings and private residences, including the Iași railway station (1869–70), the Czernowitz Synagogue,[4] the Galician Savings Bank in Lviv, Church of Franciscan Sisters in Lviv, Jan Styka's villa, and the Tyszkiewicz Villa in Vilnius.