Diyarbakır traditional houses, which have witnessed many civilizations, are an important part of the urban identity. Diyarbakır traditional houses have an important place in architecture in terms of socio-cultural structure and history. Traditional houses need to be preserved and passed on to future generations. Today, there are different protection methods. One of these methods is refunctioning. Problems arising from new functions are observed in the preserved structures by re-functioning. It should be taken into account that the new function should not damage the building, and that the cultural and historical value should be preserved, and at the same time, the increasing user requirements and comfort should be provided with the function. The study was carried out in order to emphasize the importance of ergonomics in repurposed traditional houses and to determine whether it meets the comfort of the user. As a result, it is expected that traditional houses will provide ergonomic features with new functionality. In the study, ergonomic problems that arise due to the new function in traditional houses that are functional as cafes and restaurants were examined. For this purpose, eight traditional houses functioning as cafes and restaurants were chosen. Afterwards, a questionnaire was applied to the users for ergonomic evaluation by taking data such as color, lighting, noise, human dimensions, seating area calculation, window sizes of the units as reference. With the data obtained as a result of the analysis of the observations and questionnaires, the points to be considered in the functionalization were determined.