Considering that about 40% of energy consumption of the country is in the building sector, applying criteria for designing an architecture compatible with the climate is one of the most important ways to reduce energy consumption. In this article, the criteria of the architecture compatible with the climate of Ilam city have been reviewed and presented using Mahoney index. After determining the criteria that should be applied in designing the architecture compatible with the climate, the residential buildings have been compared in three time categories of greater than 30 years (group 1), between 15 to 30 years (group 2) and less than 15 years (group 3) to extract the distance between each group and the optimal state. For this purpose, 285 residential units of different areas of Ilam city were studied using the standard questionnaire of Mahoney index. The results of the questionnaires were extracted for each group separately and these results were compared with the optimal state in Mahanoy index and were analyzed by SPSS software. Based on the given criteria of Mahoney Index, group 2 (between 15 to 30 years) has the most compatibility with local climate and group 3 (new buildings) has the least compatibility. Totally, it can be said that about 50% of the residential units in Ilam city are compatible with the climatic conditions of the area. The results and criteria presented in this study can be used in providing architectural design procedures compatible with the climate for new buildings of Ilam.