Before he became city mayor, 1920 to 1928, he visited the United States, France, Great Britain, Italy and Germany. In his open Zoo, Tuškanac passage, built urban beaches on Kvaternik Square and the British square, public restrooms on the squares of the same name (one of which is that the square has become a repository Kvaternik ZET), Stock Exchange Building (now National Bank), the Hotel Esplanade , airport on Borongaj (which landed on the legendary Charles Lindbergh), a couple of cinema halls and colleges, then the regulatory basis of the 1923rd defined Medvešćak, Zvonimir Street, Canal and Tresnjevka and more (now the City of Zagreb for 30 years was not able to define the location and content of "Hrelić"), and in May 1926. Radio Zagreb began broadcasting, first radio station in this part of Europe.

Heinzel is also the city's papers introduced the concept of the "White City of Zagreb", from which derives his understanding of how and Zagreb should have a civil and gentlemanly square, modeled on the Piazza Duomo in Milan, the Grand Place in Brussels, Piazza San Marco in Venice, Piazza Signoria in Florence, Place Concorde in Paris, Piazza Spagna in Rome, Trafalgar Square in London and Vaclav Namesti in Prague, which is a common feature that they never used the Fair organization. Thus was built near the high quality market Dolac, to which he was transferred to the green land plot Jelacic, a bit further, near the slaughterhouse and the Veterinary Faculty in the area then Sajmišna Street (now Heinzelova), made the marketplace. He also founded a company and purchased AEROPUT first passenger plane with the name of Zagreb.

We can freely say that the completion of Zagreb Dolac market has definitely got a European flair urban metropolis with many elements, but also the state of mind which is favorable to the further consideration of the urban development of Zagreb and behavior of locals and cosmopolitan city of Zagreb public services. What is continued after the liberation in 1945. when the period of 30 years substantially constructed and defined areas of Central Station to the Sava and Novi Zagreb with the Fair, then built a loop in Držićeva street and three bridges on the Sava.

Thanks Universiade 1987th successfully modernized Ban Josip Jelacic Square, built a tower Cibona, Zagreb detour road, tram crosses the Sava River, and built a second-class bridge (Adriatic), which enters the northern part of Zagreb and met with božesaćuvaj architecture, with a bunch of air conditioners at the front and clearly the inevitable commercials, which seem to indicate that in today's Zagreb can all hustle and image of the "White City of Zagreb" ..