## 1 Introduction  
Prefabricated building refers to the process where parts or all components of a building are prefabricated in a factory and then transported to the construction site, where they are assembled into a building using reliable connection methods [1]. Compared to traditional construction methods, prefabricated buildings feature standardized design, industrialized production, mechanized construction, and informational development [2], which helps with promoting energy saving and emission reduction [3], improving project quality [4], and reducing construction periods [5]. The development of prefabricated buildings demonstrates trends of globalization, technology-driven processes, and environmental friendliness. An efficient quality management system is crucial for ensuring the safety, reliability, and market competitiveness of this construction method [6]. The quality of the prefabricated building design phase significantly affects the subsequent component production and on-site assembly quality. Currently, the design phase faces issues such as asymmetry of design information, inadequate communication leading to increased design conflicts, and the inapplicability of traditional design thinking to prefabricated building design [4, 7]. Furthermore, the prefabricated building requires modularization, standardization, and precision, and the current quality management system in the construction industry is only partially suitable for prefabricated buildings. With the development of building information modeling (BIM) technology [8] and the Internet of Things (IoT) [9], among other information technologies, the quality and efficiency of prefabricated buildings have been significantly enhanced, making the production of building components more precise and efficient. Particularly, BIM technology offers comprehensive technical support, enhancing management levels, removing barriers in information communication through effective information quality management schemes, and providing new possibilities and directions for improving the quality management of prefabricated buildings [9]. However, while the advantages of BIM technology lie in the richness, shareability, and integration of architectural information, the BIM models still need to be improved by three-dimensional effects and animations and provide an intense immersion and real interactive experience. It is difficult for non-professionals to interpret drawings, models, and data, leading to insufficient feedback on the design. Additionally, virtual reality (VR) technology, as a novel design communication tool, has the advantage of enhanced visualization [10], allowing users to have immersive and interactive experiences in virtual scenes, facilitating design from a human-experience perspective [11] and fully expressing design intentions. However, current research and development mainly focus on hardware devices with most applications being in the realm of the final virtual reality effects. To overcome the limitations of existing methods, this study proposes a framework that applies BIM and VR integrated technology in the design phase of prefabricated buildings, aimed at assisting architects in process design and outcome expression. This will help improve communication efficiency, reduce design conflicts, and enhance the quality of the design phase, thereby further improving the overall quality of prefabricated buildings. This study explores critical quality factors in the design phase of prefabricated buildings, addressing quality issues such as fragmented design phases, inefficient collaborative design, and low-level visualization affecting design decisions, and it proposes a quality management framework for the design phase based on BIM and VR technologies. This framework outlines the basic requirements, design work content, and specific application functions of BIM and VR that can be implemented to enhance the design quality across six phases of prefabricated building design.