By simulating thermal conditions in 4 existent Viennese office buildings, the project aims to investigate potential for optimization of thermal comfort in office blocks despite increased outdoor temperatures due to climate change. This goal is supposed to be achievable without the appliance of mechanical cooling. Options for optimization are scrutinised in 2 main areas: firstly, the building envelop holds several potentials to minimize solar gains - most of which are already in usage today. However, the general interplay of different measures for sun shading still seems to be highly improvable. This is especially true in reference to the interaction with building technology and HVAC which form the second main area of investigation. Therefore, various feasible interventions in the areas of both building envelope and technology are investigated regarding their impact on peak temperature attenuation and increasing heat storage capacity. The efficiency and sustainability of such measures are tested by means of thermal building simulation. Control engineering and feedback control systems form an integral and crucial part herein.