Briefing is the process of determining requirements through communication between an architect and a client for project success. Essentially briefing utilizes knowledge management tools and techniques. This study aims to explore the issues and problems of briefing with a focus on requirement elicitation and validation by investigating the attitudes and approaches of industry practitioners. A literature review was conducted to design the questionnaire survey and interviews. A survey in three themes: organizational information, knowledge capturing in briefing, process for requirement elicitation and validation has been applied to 24 respondents, and 11 interviews were held with openended questions. The survey was conducted among the members of the Turkish, İstanbul, and İzmir Association of Architects in Private Practice. Interviews were held with architects (founder/partner) from Ankara. Issues, problems, methodologies for requirement management, and knowledge processes were explored. The involvement of the user in briefing and the experience of stakeholders are important for project success. Furthermore, the knowledge processes: of capturing, indexing, recording, and archiving are used for requirement elicitations. Using comprehensive frameworks for briefing and technology like Building Information Modelling may increase the benefits; however, the awareness of architects in this field is low. Discussions about the issues, problems, and success of briefing processes were held to state the requirement management approaches of architects. The study implicated the importance of requirement validation before and during the design process, the difficulty of capturing knowledge from the client, and assuring the user’s involvement with proper experience level in the briefing. These may be used to improve practical studies on requirement management. Furthermore, the study is an actual record of vocational practices, so with the implementation of other research, it contributes as a comparison and evaluation point.