The 2009 Building Physics Conference will be organized in Istanbul, Turkey by the Physical Environment Control Unit of Istanbul Technical University, Faculty of Architecture. The main theme of the conference is “Energy Efficiency and New Approaches in Building Physics”. The conference will also focus on various subjects within the field of Building Physics. The conference will provide a forum for scientists, researchers and practitioners from all over the world to disseminate technical information, new ideas and latest developments and discuss future direction in the fields of building physics. Moreover, the conference is expected to form a platform through which the developed and the developing countries exchange their knowledge and experiences.