The factory also needed storage space and housing for the managers and workers. In the end there were a dozen buildings in the sugar factory area. A number of architects took part in the planning and development of the area. After the First World War the factory became a part of the company Suomen Sokeri ('Finnish Sugar') which dominated the trade. The head offices of Suomen Sokeri were built along Mannerheimintie street in the 1950s. The building still stands today. The sculpture, 'Sokerityttö' ('The Sugar Girl') by Viljo Savikurki is there as a reminder of the sugar factory. Sakkaroosi ('saccharine') house was built on the site next to the sugar factory at the beginning of the 1970s.

     The city bought the plot and demolished the empty buildings. The academic Alvar Aalto, who had made the plans for the city centre, suggested that a new opera house should be built on the plot of the sugar factory. The idea aroused controversy but after going through many stages the debate resulted in the city giving the plot for free to the state to build the opera house. The three architects Eero Hyvämäki, Jukka Karhunen and Risto Parkkinen won the architectural competition in 1977. The new opera house was completed in November 1993.