The Ghanasyam House of Sivasagar district, Assam, India, is one of the detailed specimens in the ornamented brick architecture monument of the Ahom Dynasty. The monument is built during the reign of Ahom king Rudra Singha (CE 1696–1714), and it is protected under the Archaeological Survey of India, Guwahati circle, Assam (ASI). Multiple terracotta plaques are being used for the ornamentation that includes motifs, patterns, symbols and sculptures. This paper aims to present a visual analysis of the motifs and patterns of the monument. The collected data of ornamentation are sorted considering a categorization theory. This paper investigates the visual composition analysis and symmetrical analysis of the ornamentation. The results provide detailed insight into the visual attributes of the motifs and patterns. The paper identifies rudimentary principles in the composition of the ornamentations within a specific frame of reference. The quantitative data analysis identifies the dominating motifs and pattern types and multiple symmetry operations. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.