At the beginning of the 20th century, the hotel entered a decisive phase of expansion. In 1911, two adjoining buildings were incorporated, increasing capacity with 100 new rooms and elegant function rooms. However, history also brought a period of pause: in 1945, the hotel closed for ten years after being occupied by Russian troops following the Second World War.
After a brief reopening, the building was acquired by the Austrian state and made available to the International Atomic Energy Agency, which established its headquarters there for more than two decades. It was not until 1989 that the property regained its hotel vocation. Following an ambitious restoration led by All Nippon Airways, the building was returned to its original size, its historic façade was preserved, and the interiors were completely renewed, integrating cutting-edge technology without sacrificing its classic spirit.
On 14 June 1994, following an investment of 100 million euros, the hotel reopened its doors, achieving a perfect balance between its brilliant past and a resolute взгляд towards the future. Since then, the Grand Hotel Wien has continued to write its story as one of the great icons of Viennese hospitality—true to its legacy and in constant evolution—offering an experience where tradition and excellence continue to lead the way.