The study investigates the early phases of the apartment block development in Istanbul. This process, which took place in the second half of the 19th century, represents distinctive features. It reflects the “west-oriented” facet of the Ottoman Empire and sheds light on the transformation of the urban fabric from pre-modern to modern. For the clarification of this unique process, the study uses the Annuaire Orientals related to the years of 1889, 1893, 1896, 1910 and 1922. Through the Annuaire data, the ‘social profile'' of the early apartment residents and the ''spatial setting'' of apartment blocks are investigated.