In 1898 Kärntner Ring 3 and Kärntner Ring 5 were taken over by the hotel and rebuilt by the architects Emil Brüsseler and Gustav Wittrisch. After that, The Bristol included a total of 235 bedrooms, a large dining room, a glass-roofed courtyard with a capacity for 150 guests, a breakfast room seating 70, and several smaller public halls – as well as an electrical lift which was the first one of a kind in Vienna. The interior design includes two seats as apparently, the lifts were ‘quite slow’ and ladies in their heavy dresses appreciated the opportunity to rest their feet.
After the death of Karl Wolf, his brother Arthur Wolf took over the running business of the modern-day Bristol and made the hotel a "fashionable residence of the elite of European and American society, situated in the most central and convenient part of the city", as the Agard´s Guide of Austria was describing The Bristol. In 1913, further expansion of the hotel followed with Kärntner Straße 55 and Kärntner Straße 53 (now Mahlerstraße 2) according to the plans of Ladislaus Fiedler and Pietro Palumbo. These also included the demolition and reconstruction of Kärntner Ring 1, the oldest privately owned building near the opera. The reconstruction was carried out by Wilhelm Schallinger between 1913 and 1916. Neues Bristol was reopened in 1916. The complex reached from the Akademiestrasse to Kaerntner Strasse (Kärntner Ring 1-7). The building itself was Art Noveau, the interior design Baroque and Biedermeier. The original wings were now called Altes Bristol. Both houses were connected to each other by passageways in the basement and on the ground floor.
On February 24th in 1921 the company Hotel Bristol AG was formed. Schallinger's entry into this hotel company saw the unification of the hotels Altes Bristol and Neues Bristol. Both houses combined had 289 rooms with 402 beds and 204 private bathrooms at this time. Due to the economic crisis in 1930, the Österreichische Bank Creditanstalt became the sole owner and lead the hotel through all its ups and downs, especially the bad times during the Second World War.