The technical challenges of sustainable design and the advances in the development of analytical tools have stressed the role of quantifiable analysis in the design process. However, architectural practices face the difficulty of integrating analysis with traditional design procedures that are mostly based on intuition. This paper explores the role that analytical tools play in the design process, based on five case studies of contemporary architectural practices in Europe that are considered to be pioneers in the field of sustainable design. A specific non-domestic building designed by each practice was chosen as an embedded unit of analysis with the intention of mapping its design process. The data collection strategies included interviews with architects, engineers and clients; as well as compilation of graphic information including drawings and reports; and observations. The case studies suggest that the role of analytical tools is counterbalanced by intuitive elements within a social framework of interdisciplinary teamwork. It is stressed by the degree of complexity, innovation and risk of the project and by the level of expertise of the design team. In addition, it is usually complemented by a role of communication and persuasion of client bodies that has proved to be as important as their main analytical role.