In recent years, a large number of design support tools (DSTs) have been developed to address the ever increasing complexity and fragmentation of the architectural design process. Despite the omnipresence and the wide variety of DSTs available to architects today, literature reveals that there is still a mismatch between existing tools and design practice. Further examination of this discrepancy might reveal possible strategies for the improvement of tools. Therefore, this study investigates the Flemish architectural practice directly through a large-scale survey including 629 architects (nearly 10% of the population). The survey was based on a practice-oriented conceptual framework, which was developed as a theoretical background for this study. First the nature of the design process was explored through extensive literature review. In addition to this, a study of tools and possible classifications was carried out. Although numerous studies are available that provide a possible classification, most focus on specific design aspects, for instance sustainability or user-centered design. However, there is no general outline of tools available that would be adequate for the purpose of this research. The DSTs included in this study range from sketches and checklists to 3D CAD and simulation software, in other words any instrument intended to support one or more aspects of the design process. The findings from both literature studies were synthesized in the conceptual framework. This framework presents the design process as a linear process, consisting of the conceptual design phase, the preliminary design phase, the building permission phase, and the construction phase. Six categories of tools were defined, according to the roles they play in the design process, namely knowledge-based, presentation, evaluation/analysis, structuring, modeling, and communication. A tool can belong to one or more categories. The mapping of these roles on the design process resulted in the final framework, which was then used as a base for the questionnaire. The survey aimed at gaining insight into the different DSTs and their corresponding roles, as well as the design phases in which they are used or most needed by Flemish architects in architectural practice. In addition to this, the survey contained questions about the influence of tools on design decision-making, and the specific characteristics and qualities the designers prefer for design support tools. A final part of the survey asked about general background information, such as the respondents age, size of architectural firm and types of projects usually undertaken. The results of the survey reveal that there are distinctly different needs for each of the roles defined, as well as a specific frequency of use within each design phase. Furthermore, the most popular tools often encompass multiple roles. Additionally, clear expectations for future tools are defined. Finally, the data collected show researchers and tool developers what kind of support designers need in the different stages of the design process, and may help them to develop DSTs accordingly, to maximize their usability and eventually contribute to decrease the gap between tools and practice.