The year 1948 brought with it a number of political changes. The communist coup in Czechoslovakia significantly affected the fate of the villa, which became the so-called "tenant villa". In 1951, František Müller poisoned himself with carbon monoxide while lighting a fire in the villa's boiler room. The Müllers' only daughter Eva emigrated. The villa remained as a single owner. In 1955, the villa became state property by decision of the District National Committee in Prague 6, and the depository of applied art of the National Gallery in Prague was relocated to the building. In 1959, the villa was definitively expropriated and Mrs. Milada Müllerová was allocated a two-room apartment with a bathroom. The ladies' boudoir and library served as her apartment, while the other rooms of the villa housed the offices of the national enterprise State Pedagogical Publishing House. Milada Müllerová made great efforts to save the villa. She asked the Swiss architects Frank Gloor, Rolf Gutmann and Felix Schwarz to prepare a proposal for the establishment of an Adolf Loos center in the Müller villa.

It was fortunate for the future fate of the villa that the collections of František and Milada Müller were purchased by museums and galleries. The same was true when dealing with the estate of Milada Müllerová, who died on September 8, 1968. A month later, on October 15, 1968, the Müller villa was declared a cultural monument of the Czech Republic.

In 1995, the Prague City Council decided to purchase a five-eighths share of the Müller Villa from Mrs. Eva Maternová, daughter of Milada and František Müller, into the ownership of the City of Prague, which entrusted the professional administration of the building to the Museum of Prague. In 1998, the renovation of the villa began.