The most important problem today is how to protect the historical heritage. It is necessary to provide contemporary uses for protecting the historical heritage and transfer this attitude and new life to these buildings in order to carry them to the future generations. The method required for this attempt is adapting these old buildings when the original function is no longer relevant or desired with new uses which is called as adaptive re-use. The subject of this article is adaptive re-use methods and challenges or benefits of religious buildings. The religious buildings have a slightly more special significance than all other monumental buildings. When restoration of religious buildings come into practice, this case is even harder than restoring any kind of monumental buildings, when faced with adaptive re-use examples of religious buildings, this kind of function variations in order to protect the meant values, the researches to be made and the ways to be followed can be described in a systematically manner as: re-functioning process. Adaptation of the new function to the old building. Design concept in the revalorization. In this study the cases of adaptive re-use examples of religious buildings with many implementations from Turkey and different places of the Europe and how the architectural design concept is implemented in these buildings is researched. (C) 2013 Elsevier Masson SAS. All rights reserved.