Notre Dame du Rosaire Chapel is a part of Saint Euphemie School Complex and was built as a school for nuns. The site is comprised of a school, a monastery and a chapel building and is currently in use as Kemal Ataturk High School. Present structure is assumed to be built in 1912 after original wood structure in 1911. Chapel never had a comprehensive repair until 2010 and hencee maintained its original characteristics. Kadikoy Municipality bought the building in 2010. Restoration project of the chapel was held within Yeldegirmeni Revitalization Project and has been prepared as a response to adaptation and reuse problems of numerous buildings in Ottoman territory built for missionary activities in 19th century. Here, we will discuss the methods and the decisions taken during preparation of restoration project of Notre Dame du Rosaire Chapel.