The idea of building a new home for Ostrava's local government authorities was first mooted just before the First World War. The existing city hall – on today's Masaryk Square – was too small and shabby to meet the needs of the rapidly growing city.
The plans were interrupted by the sudden outbreak of the First World War. When the war ended, the emergence of two new factors meant that the new city hall could not be delayed any longer: firstly the plans to create a “Greater Ostrava” metropolitan area (by merging Moravian Ostrava with its surrounding towns and communities), and secondly the planned administrative reforms according to which Czechoslovakia was to be divided into regions. The law stated that “municipalities in which regional authorities will be established must acquire buildings containing suitable office premises.”
Officials began a frantic search for a suitable site to build offices for both the city and the planned new region. Several locations were considered – including one near the Husův Sad park, one in the Fifejdy district and one on Nádražní Street – but officials eventually settled on a site recommended by the architect Josef Sakař, where there was a restaurant and a shooting range owned by the local gun club. The final decision was taken in the summer of 1923.
A competition to design the building was announced later the same year, but no overall winner was chosen. The design adjudged to be the best was submitted by the Brno-based architect Vladimír Fischer and the Ostrava building contractors Kolář & Rubý. In 1924 the city commissioned these entrants to draw up a definitive joint project.
By the end of 1926 the first part of the building was almost complete and work continued on the central part and the south wing. However, there were problems with ground stability which required the suspension of work for testing and the insertion of a specially designed 1.3 metre thick reinforced concrete panel under the central part of the structure. This caused a delay of several months, but by the end of 1928 the southern wing had been completed, followed in 1929 by the central part – except the tower, which was altered considerably compared to the original plans. Originally the design had called for a lower, bulkier structure using reinforced concrete. The plan was eventually reworked to create a lighter, steel-framed structure which would have a viewing platform at the top, but otherwise would contain no rooms. This new tower had two advantages: it cut down the weight of the central part of the building and it also reduced building costs – which had already exceeded 50 million crowns.
The builders of the New City Hall also paid careful attention to the interior décor, designed by the architect Karel Kotas. Public rooms featured extensive use of marble, while the council chamber and mayor's office are clad in rare wood.
The completed New City Hall was ceremonially opened on 28 October 1930, 12th anniversary of the establishment of the independent Czechoslovak state.