Predicting current energy demand and future energy consumption of buildings is the challenging experience for architects. Although there are various dynamic simulation tools that enable them to calculate building energy performance, the complexity of tools poses problems to model, understand process-centered simulation studies and interpret the results. This thesis aims to present, test, verify and criticize the modeling, simulation and calibration processes of residential building from architect's perspective. One of the effective ways to overcome global warming problem is by immediate involvement of architects into energy modeling process. Therefore, the study criticizes the role of architect in process-centered modeling. Process-centered modeling is tested with existing residential building conditioned with air-source heat pump in İzmir-Turkey. Indoor and outdoor environment were monitored from July 2009 to June 2010. Digital model of the building was created by using DesignBuilder dynamic modelling tool, and calibrated for three different periods of heating, cooling and transition. The problems faced during modeling and simulation based on professional knowledge of the architect and simulation tool was exemplified. Finally, the survey was conducted to verify the role of architect tool users in modeling process. Consequently, case study exemplified how the architect conducts a processcentered modeling, and survey showed how his/her modelling experience and knowledge is essential for right management of design process. Mechanical systems modeling is still challenging issue requiring knowledge and experience for architect users..