## 1 Introduction  
The global construction industry is pursuing the conversion to a digitalized smart construction system through the convergence of Fourth Industrial Revolution technology, spurring fierce competition to improve productivity and lead the market in the construction industry [1]. Major issues in conventional construction methods are inadequate response measures for productivity, digitalization, and aging, in addition to the need for changes in conventional construction work methods due to an expansion of contactless types of work [2; 3]. In particular, the digitalization index of the construction industry is lower than that of other industries such as agriculture, manufacturing, and information communications [4]. Furthermore, the average age of infrastructure technicians is gradually increasing, while the working age population is predicted to decrease [5]. Due to the expansion of contactless types of work during the COVID-19 pandemic, changes in the construction industry are occurring through the utilization of the metaverse where virtual and real technologies involving extended reality (XR), artificial intelligence (AI), the Internet of Things (IoT), and blockchain are being applied [6]. Especially in the maintenance domain of the construction industry, digital twins have been actively introduced based on the technologies of the Fourth Industrial Revolution, as explained above. The emergence of a digital twin is attributable to advances in various information technologies [7; 8; 9]. Various technologies for expressing the real world in three dimensions such as computer-aided design (CAD) and building information modeling (BIM) have matured,thus enabling the design of a newly created real world (reality) in three dimensions. Other technologies such as light detection and ranging (LiDAR), photogrammetry, and Pictometry realize real objects (buildings, roads, rivers, forests, etc.) as three-dimensional spatial information, and the advancements of sensors help to identify real-world situations [10]. In addition, communications and internet networks such as 5G transmit sensed data in real time. Similarly, the circumstances for forming a digital twin have been established through the convergence of a variety of technologies including the visualization of three-dimensional models, advancements in big data and artificial intelligence (AI) technology, and simulation technologies such as agent-based models. Owing to a growing interest in 3D spatial-information-based facility management through digital twin technology and the digitalization of deteriorated social overhead capital (SOC) and disaster response services in recent years, the utilization of various three-dimensional spatial models has also increased. Such virtual models are being used as base models in diverse areas such as facility management, urban management, and disaster management, and there is a growing need to establish and manage interior as well as exterior space information. Existing spatial information and application services have been developed mostly for exterior spaces, and data models have also been defined and developed with a focus on exterior spaces. Moreover, the models have been developed mainly to express objects and thus have insufficient property information, which limits their performance in spatial analysis. Thus, an interior space data model is needed to support the services using 3D interior space data and geographic information system (GIS) technology [11]. These data models must fundamentally provide visual information about an interior space and be capable of performing spatial analysis.