## 1 Introduction  
In recent years, activities in the construction industry have progressively been shifting to building renovations, retrofits, expansion, and the deconstruction of existing buildings. This phenomenon is especially notable in the developed countries with low new construction rates and is mainly caused by limited resources, enhanced sustainability targets, and stricter regulations from many authorities that have jurisdiction (AHJs) for energy and resource efficiency in buildings [1, 2, 3]. Although there is a massive increase in construction projects taking place within existing buildings, such projects typically face multiple challenges, including physical constraints with existing facility components, high uncertainty of existing conditions, and limited access to the work area [4, 5]. Moreover, these projects can face additional challenges, as part of the facility may have to remain operational during the construction phase [6, 7]. All these complications and challenges subsequently lead to the fact that many of the construction projects on existing buildings, including renovation and expansion projects, become very complex and require cautious planning and implementation. As a result, successful management of the building design coordination process becomes critical to the efficient delivery of cost-effective and quality projects [8]. In this regard, the construction methods that utilize Building Information Modeling (BIM) have the potential to address many of the significant challenges encountered in design and construction of renovation and expansion projects [9]. The use of BIM has increasingly grown in the Architecture, Engineering, and Construction (AEC) industry due to its many benefits during the design and construction phases of building projects [10; 11; 12; 13]. BIM allows practitioners to develop, capture, and manage building information, which can subsequently enable activities such as as-built documentation, calculation of alternatives and optimizations, onsite progress tracking, measurements, and monitoring activities, which are essential to improve project management and risk mitigation during a facility's operations and renovation phases [14]. Using BIM can be especially beneficial in construction projects involving existing buildings. According to [15], the emerging benefits of BIM in this area are as follows:  
* Utilizing BIM to create a digital mockup of the existing environment that can be seamlessly integrated with the designed model. * Advantages gained in project implementation by using 4D simulations, i.e., 3D models plus project schedule (time). * Improved project management and coordination among multiple disciplines that can result in efficient project financials and planning. * Effectively conveying the renovation or expansion objectives to clients and project partners, including aspects such as comfort, aesthetics, and energy performance. * Providing more reliable estimations of construction waste volume during the renovation or destruction process. * Enabling the use of prefabrication, resulting in more efficiencies. * The standardization of spaces for equipment and building components that can subsequently lead to optimizations in cost, time, and quality. Despite the numerous benefits of using BIM in construction projects, however, the use of BIM in renovation projects has been limited [14; 16; 17], and project stakeholders continue to encounter challenges, particularly in the realm of design coordination [8; 9; 18; 19]. These challenges can be exacerbated when projects include existing buildings, such as in renovation and expansion projects. That being said, the extent of these challenges can vary depending on the level of BIM implementation integrated in a project [18; 20]. Therefore, despite BIM's potential to enhance project management and operational efficiency, its adoption in the context of complex renovations is fraught with unique challenges that necessitate further in-depth investigation.