Purpose' In the digital age, constant changes in libraries inform contemporary building design. An innovative library building design is a complicated process and can be viewed as a continuous process of the use of tacit and explicit knowledge and innovative tools and approaches. Knowledge management (KM) can bring about the much needed innovation, and transform tacit knowledge to explicit knowledge. For the design of a library to be successful, it is necessary to apply KM to library building design. The purpose of this paper is to look at key change impacts, to explore how to manage knowledge in building design and to identify key design principles. Design/methodology/approach' This paper looks at key change impacts, explores how to manage knowledge in library building design and pinpoints design principles. Findings' This paper finds that KM can be vital to library building design, and it can be used in all stages: to examine the internal and external environments, transform tacit knowledge to explicit knowledge by using portals, and analyze existing and future issues and trends. When effectively used, KM will result in innovative design strategies and also will reduce the time and costs of the building design and plan processes. The main principles of library building design are flexibility, accessibility, safety and security, applicability, adaptability, efficiency, and sustainability. Practical implications' This paper provides a useful overview of how to manage knowledge in library building design and design principles. Originality/value' The views, discussions, and suggestions will be of value to improve the effectiveness of library building design.