The main objective of this research is to expand the concepts of interactive multi-objective design in the field of architecture design, and demonstrate the contribution of parametric modeling, genetic algorithms, computational simulation and an interactive programming environment in the process of decision making in the preliminary stage of architecture design. In this research, an interactive GA-based computational method is employed to consider both technical and non-technical requirements in exploring the design solutions of a one-bedroom house unit. The design objectives, in this case, include thermal performance, material cost, and the resident’s lifestyle. Ultimately, it is to be observed how the interactive approach of the exploration method can help the decision maker with objective trade-offs.