A review over 19 th century archive documents (keşif defterleri) on Ottoman repair works in converted Middle Byzantine Churches in Istanbul

The starting point of this study is formed by deficiency of studies on the usage preferences, conservation approaches and intervention procedures on the Byzantine buildings in the Ottoman period. Our research covers the building that converted into a mosque and is existed cost estimates in Prime Ministry Ottoman Archives. So it is a part of the comprehensive study about the Bizantian Buildings in the Ottoman Period.In this context Ottoman Period renovations cost estimates of the sample buildings are examined and prepared in transcriptions and than the buildings were observed with the obtained datas. Some informations as which tools were used,in which occupational fields's employees were operated, in which intervention forms were applied have been identified.So in this context all kind of original informations that will emerge is important for the history of architecture and restoration Keywords: Restoration, The Ottoman Architecture, archive documents.