The present study examines a document of construction of an Ottoman house remaining in Cairo, namely that of the house of Mustafa Jaafar Elkabeer dating back to 1151 H. (1738 A.D.). This house is currently located to the left of the passerby El Darb El Asfar to Eljamalia. The study displays the text of the document, under investigation, in order to define the old location and the original status of Mustafa Jaafar house. Then, it looks for the original establisher and who was responsible for its renewal, i.e. Ismael Elmasabny. Furthermore, it corrects some opinions in literature and reveals the importance of the documents in studying the history of the houses’ construction. Additionally, it defines the house’s original status before renewal and reconstruction according to the document, under investigation. Accordingly, it reveals the errors of construction description in literature and the misunderstanding of the mortmain property document dating back to 1171 H. (1757 A.D.) in a previous study that examined a re-conceptualization of the house, but it hadn’t defined the original form of the house. However, the researcher identified this based on the construction document, under investigation.