Buildings cause environmental impacts through their life cycles. Ecological building design criteria, which appeared to decrease these impacts, aim to make designs sensitive to environmental problems, to protect the ecological balance, and to fulfill the required comfort and health conditions. In the context of this paper, ecological building design criteria were determined in global scale as energy conservation, water conservation, material conservation, and livable design, and applications of these criteria were described. Later on, Ankara City located in the middle Anatolian region of Turkey was selected as working area, and the applicability of the ecological building design criteria in the selected area have been identified. An ecological building was designed in Gazi University Campus in Ankara, and the design was examined according to the presented ecological building design criteria.