Mu.ZEE is housed in a building with a rich history. Until 1981 it was part of the SEO, Spaarzaamheid Economie Oostende, founded in 1892. This cooperative became a success story in the Ostend distribution sector and soon branches were established in Ostend and along the coast. Looking for new headquarters with a department store for the SEO in the late 1940s, the decision was taken to extend an existing SEO building located in Amsterdamstraat, which housed a pharmacy and beer bottling plant. The initial extension was on the Gentstraat side (now the rear of the museum and the Ensor and Spilliaert museum Wing), but the icing on the cake was the new main store with a thirty-meter long curved glass wall in Romestraat: the administration was housed in what is now the Raoul Servais Wing; shoes, medicines, clothing, food - you name it, it was here. At the SEO, tokens were used to make payments, not money. The SEO was a major employer for the local population and many people from Ostend knew or had someone in the family who worked at the Coo, as the SEO was popularly known. Over Mamazels, Stongs en percenten. Een geschiedenis van S.E.O. 1892 – 1981 by Olivia Simoen tells the rich story of this cooperative.
However, the success story came to an end in 1981 when it went bankrupt, but five years later, in 1986, the doors reopened: the Provincial Museum for Modern Art, better known under the iconic name of the PMMK, found a safe haven there after several years of alternating between Bruges and Ypres. The commercial premises with their stories disappeared into the history books forever, finally making way for museum spaces. In the 2000s, the Provincial Museum for Modern Art also found its way to the former department store. A new museum under the name Mu.ZEE was born in late 2009.
The architect Gaston Eysselinck (1907-1953) was behind a number of branches for the SEO, including the new headquarters with department store in Romestraat. Between 1945 and 1953 he worked in Ostend: in addition to a few houses, he also put his name to the PTT/RTT building, now the Cultuurcentrum De Grote Post (p. 297 ff. Marc Dubois, Gaston Eysselinck. In de voetsporen van Le Corbusier, 2019).