Scan-to-BIM and Digital-Twin-Enabling Documentation of Architectural Heritage: A Comparative Technical Assessment of Ecuadorian Practice (2015–2025)

Digital-twin technology promises real-time virtual representations of the built environment, yet accurate 3D documentation—its foundational layer—remains underdeveloped for architectural heritage in Ecuador, where 170,000 inventoried assets face seismic exposure and limited institutional capacity. This study examines scan-to-BIM and 3D documentation practices underpinning digital-twin creation for Ecuadorian built heritage (2015–2025) and proposes the C1–C5 matrix as a diagnostic tool for digital-twin readiness. Here, 3D documentation precedes the digital twin, not the reverse. A qualitative-descriptive design combined structured searches of international and regional databases and 38 Ecuadorian university repositories with a comparative analysis of eighteen indexed cases—including scan-to-BIM and HBIM workflows—coded via the C1–C5 matrix and validated by a five-member expert panel. Results identify three stages—exploratory (2015–2018), consolidation (2019–2022), and diversification (2023–2025)—with SfM photogrammetry and hybrid methods each representing 27.8% of cases, and geographic concentration in Azuay and Loja (66.7%). A structural gap persists between academic production and indexed dissemination: only 12–15% of relevant theses reach indexed publication. The study concludes with guidelines—shared equipment networks, interuniversity training, and open-source migration—to strengthen digital-twin documentation foundations in comparable Latin American contexts.