## 2 Literature Review
### Building Information Modeling Implementation in Vernacular Architecture  
VA, characterized by its utilization of regional resources, traditional craftsmanship, and environmental responsiveness, represents a significant cultural legacy and a valuable source of inspiration for sustainable contemporary design principles [45]. Initially developed for new construction projects, BIM has expanded into heritage preservation through the framework of HBIM, which facilitates the precise documentation and management of vernacular structures. Technologies such as laser scanning and photogrammetry enable the creation of highly accurate 3D models, capturing intricate details unattainable through conventional survey methodologies [46]. [PERSON] et al. [47] described HBIM functions as a semantic framework that integrates geometric representations with diverse datasets, encompassing construction techniques, material properties, and historical information, thereby proving particularly effective for preserving the cultural significance inherent in VA. Nevertheless, the standardized data structures inherent in BIM technology pose challenges in accurately representing the unique and often non-uniform geometries characteristic of vernacular buildings. This necessitates the development of specialized parametric object libraries, derived from integrated scan data and traditional construction expertise [45]. This approach safeguards critical conventional knowledge and supports the integration of vernacular principles into conceptual design for contemporary architecture, fostering culturally resonant and sustainable solutions. Implementing BIM in VA presents significant technical and conceptual challenges, particularly concerning the modeling of complex architectural geometries. [PERSON] et al. [48] highlighted that, while modern scanning technologies generate detailed point clouds, the automated conversion of this data into parametric BIM models is often hindered by the absence of robust feature recognition algorithms. Consequently, workflows frequently rely on time-consuming manual or semi-automated modeling approaches. Standard techniques, such as manual modeling, fitting primitive shapes to point clouds, or extruding surfaces, \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Region** & **Structure Used** & **Design Method** & **Measuring Tool** \\ \hline \multirow{3}{*}{North} & Truss Set, stacked timber & Based on triangle ratios, length, and height & Sam ruler–right angle \\ \hline \multirow{3}{*}{Central} & 4 components: Column, Rafter, Tie-beam, Purlin & Based on beams, columns, and slope, 50–65\% & Nach ruler–equilateral triangle \\ \hline \multirow{3}{*}{South} & 3 columns: 1 large center, 2 small sides & Based on body dimensions, and slope 60–65\% & Nac ruler–equilateral triangle \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of VA styles in regions of Vietnam. are commonly employed; however, these methods often prove insufficient for accurately representing the diverse and irregular forms inherent in VA [44; 47]. Furthermore, [PERSON] et al. [49] underscored the fundamental mismatch: the inherent conflict between BIM's standardized, uniform framework and the idiosyncratic, non-standardized configurations characteristic of VA, for which the BIM platform was not originally designed. To address this, [PERSON] et al. [50] advocated for adaptable object libraries with pre-defined attributes to streamline modeling and enhance HBIM's effectiveness. However, a critical challenge persists in defining the appropriate level of detail for HBIM models, particularly for conceptual design applications, where balancing detail with stakeholder needs, such as those of heritage conservationists or architects developing new VA-inspired structures, requires further exploration [45]. In addition to its role in heritage conservation, the application of BIM to VA holds considerable promise for fostering sustainable modern design.