This study proposes a framework for simultaneously addressing qualitative and quantitative decision-making criteria during the early stages of the design process. It investigates the features and characteristics in an architectural tool that enable an architect to simultaneously address qualitative and quantitative criteria during the early stages of the design process and the requirements for implementing these features and characteristics inside a tool/working environment. It adopts a four-step methodology based on the qualitative methods of inquiry. These steps include logical argumentation based on the literature review, interviews, immersive case study, and Delphi method. The proposed framework provides a map of the areas and the themes that need consideration when developing an architectural tool that is expected to simultaneously address qualitative and quantitative criteria at the early stages of the design process. It categorizes the themes in three main areas: the themes concerned with qualitative studies, the themes concerned with quantitative studies, and the themes concerned with bridging the gap between qualitative and quantitative studies. The framework suggests that four major themes need consideration while developing architectural tools to support simultaneously addressing qualitative and quantitative criteria: Imagination Stimulation for qualitative studies, Knowledge Acquisition for quantitative studies, Architect as Toolmaker and Design Environment Coordinator, Hybrid Environment, and Interface for the synthesis of qualitative and quantitative studies. For practicing architects, the framework provides guidance to choose proper tools and form their design environment. Moreover, this study provides a new model of communication between the architecture community and the software developers. / Doctor of Philosophy / Any architectural project consists of numerous decisions that the architect must make. These decisions have different characteristics and can be categorized in many ways. One way to categorize them could be based on the nature of the criteria that the architects use to evaluate the results of their decision. In this manner, these criteria can be either qualitative or quantitative. Addressing these two different kinds of criteria demands entirely distinctive sets of skills. Architects are trained to address these two fundamentally different kinds of criteria, consciously or not. However, the reasoning process is much more complicated when the decision demands addressing qualitative and quantitative criteria, simultaneously. There exists the possibility that one criterion or one set of criteria may overshadow the rest if this complex task is approached without conscious planning by the architect. This study proposes a framework for simultaneously addressing qualitative and quantitative decision-making criteria during the early stages of the design process. It provides a map of the areas and the themes that need consideration when developing an architectural tool that is expected to simultaneously address qualitative and quantitative criteria at the early stages of the design process and uses several graphical representations to categorizes these themes based on the needs and objectives of the user.