This paper presents two case studies conducted in Architectural Design education in order to meet understanding and ability criteria in MIAK (Turkish Architectural Accrediting Board) and NAAB (National Architectural Accrediting Board) for 'sustainability'. The main purpose of this clause is to reinforce students' ability to design projects that optimize, conserve or reuse natural and built resources; their ability to provide healthy environments for occupants/users, and reduce the environmental impacts of building construction and operations on future generations through such means as carbon-neutral design, bioclimatic design, and energy efficiency. First-year undergraduate architecture students provided the setting for Case Study 1. A comparative study was implemented in a basic design studio between two distinct groups (a test group and a control group) mandated specifically with awareness raising. At semester's end, both groups' projects were reviewed and evaluated via questionnaire. Third-year undergraduate architecture students provided the setting for Case Study 2. An experimental study was carried out within the context of green design education, with the purpose of reinforcing understanding and ability of sustainability issues. The overall aim was to integrate building energy performance assessment into the design studio as a design decision support tool. As in Case Study 1, there were two groups. Students in the control group followed the conventional design process, while those in the test group tested the environmental performance of their proposals with computational models and energy simulations carried out with Ecotect v5.20. The conclusion reached was that a conventional design process is inadequate for a multidisciplinary knowledge-based studio aiming to integrate the theoretical basis of the energy-ecology field with architectural studio practice.