An analysis of 'representative palaces' of the Croatian capital Zagreb shows the struggle to adopt state-of-the-art construction methods and materials, to outgrow habits of the previous century and to become modern in the 1930s, both on the construction site as well as in architectural form. Most buildings constructed in Zagreb in the most important decade of the Modern movement in Croatia, even though they might have a modern architectural expression, were only structurally adjusted to the use of reinforced concrete, and there were few structural experiments and few patents. The main reason was economic, which can be seen in the choice of construction techniques and materials in all the buildings analysed. This paper provides an analysis of the history of construction in Croatia during the 1930s, giving a review of the historical context and identifying the factors that shaped the development of construction in the transition period to modernity. The construction characteristics of 'representative palaces' appear advanced in comparison with the more ubiquitous residential typology of the time.