Morphological Diversity of Thai Stupas: Developing a Synthetic Process through Modular Systems and Shape Grammar

Abstract

This research focuses on the "form-generating system" of Thai stupa architecture, aiming to expand the field of study from traditional art history toward the development of systematic design tools. The primary objectives are to analyze morphological structures and establish a standardized system of Modular Units capable of systematic synthesis into novel forms. Adopting a Design-Based Research methodology, this study conducts morphological experiments on six primary stupa typologies: The Bell-shaped Stupa (Chedi Song-RaKhang), The Prang-style Stupa (Phra Prang or Corn-shaped tower), The Prasat-style Stupa (Castle-style or Tiered-tower), The Lotus-bud Stupa (Phum Khao Bin), The Square Lotus Stupa (Bua-Liam), and The Ornate Stupa (Song-Krueang). The findings reveal that the Thai stupa can be defined as a vertical structure with a fixed hierarchical sequence of five constituent levels: 1) Lower Section, 2) Lower-Middle Transition, 3) Middle Section, 4) Middle-Upper Transition, and 5) Upper Section. By standardizing cross-sectional coordinates and interface points under Shape Grammar rules, the study demonstrates the generative potential of 7,776 unique variations (6⁵) while maintaining complete structural identity.Through Silhouette Analysis, the researcher identified three core "formal logics" acting as critical morphological variables: 1) Silhouette Directionality, 2) Silhouette Continuity, and 3) The Positioning of Inflection Points. The analysis of silhouette profiles reveals that new variations can be generated through the systematic permutation of components across five levels. By alternating between 3 lower section types, 3 lower-middle transition types, 4 middle section types, 3 middle-upper transition types, and 4 upper section types, a total of 432 unique morphological variations (3x3x4x3x4) can be synthesized. The contribution of this research lies in the proposal of a design tool that shifts the perspective of Thai architecture from traditional stylistic reproduction toward Generative Design, providing a robust, logical, and verifiable foundation for both pedagogical applications and Thai architectural creation.