With the rapid development of high-density urban areas and the construction of high-rise complexes, the number of skybridges has increased during the last 20 years. While skybridges in high-rise building complexes have been attracting considerable attention, a few studies have been conducted on state-of-the-art skybridges, but not enough typological research on skybridges has been made based on actual cases. In this study, the typological difference among skybridges sharing common properties was verified using a statistical method based on the cases of skybridges in Asia. The completion year, length, width, and relative elevation of skybridges were used for the statistical analysis. Based on the results, six skybridge types, i.e., open circulation, open sky park, open programmatic, enclosed rooftop programmatic, enclosed circulation, and enclosed programmatic, and their characteristics were derived and described by a three-dimensional plot. This study provides a comprehensive understanding of skybridges, and it can be used as a reference material for researchers to understand how high-rise complexes with skybridges will evolve and change their urban environment. It will also help architects to design skybridges and communicate with clients and the public on their value.

Graph-based spatial analysis formalizes relations among spatial units, but the formation of these units and their boundary correspondences remains under-specified. This study defines the structural stage preceding relational abstraction and establishes the conditions under which spatial units and boundary correspondences become analytically determinate. It then develops a layered spatial articulation procedure that derives spatial objects from plan-encoded architectural information by differentiating topographic substrate, building frame, spatial enclosure, and relational boundary conditions. These are organized into a base spatial graph. The topology of this graph is fixed by articulation, and its edges encode admissible relational mode combinations. Using traditional Korean housing (hanok) as an illustrative reference for the proposed methodology, the study shows that heterogeneous spatial conditions can be consistently articulated into a unified structural domain prior to relational abstraction. The resulting base spatial graph defines a finite but combinatorially extensive space of admissible relational configurations. Within this domain, graph-domain operations act without expanding the articulated structure, while certain operations may reduce it through structural transformation. The study shows that spatial units cannot be treated as pre-given entities but must be structurally constituted. By formalizing this prior stage, the study establishes explicit structural preconditions for graph-based spatial analysis and provides a consistent analytical domain for subsequent spatial interpretation.