 The most important work created in collaboration with Gyldén was the headquarters of Hackman & Co (1909) at Piispankatu 14 in Viipuri.The building represents the compositional and formal variations of Jugenstil, Art Nouveau or National Romanticism.The main elevation pediments, openings, window frames, portals, and the granite facades are quite typical of National Romanticism, which at that time was also the prevailing architectural style in Finland for key public buildings, most notably in the works of architects Gesellius, Lindgren, and Saarinen (e.g.