Usability of Heritage Building Materials: A Case Study of Hadhramaut (Yemen) and Najran (Saudi Arabia)

Abstract

This study investigates the usability of heritage building materials in two prominent regions of the Arabian Peninsula—Hadhramaut in Yemen and Najran in Saudi Arabia—both known for their rich architectural traditions and extensive use of earth-based construction. Employing a mixed-methods approach rooted in comparative case study methodology, the research synthesizes secondary data from academic publications, conservation reports, and architectural surveys to assess the performance and adaptability of traditional materials, particularly mudbrick (adobe) and layered mud (teen), timber, stone, and traditional plasters like qadad. Findings reveal that both regions utilize similar materials, yet their usability differs based on environmental conditions, socio-political contexts, and conservation infrastructure. In Hadhramaut, mudbrick offers excellent thermal performance and ease of construction, but political instability and economic decline have hindered consistent maintenance. Conversely, Najran benefits from structured governmental conservation programs, though increased rainfall presents challenges to material longevity. Quantitative comparisons of climatic data, wall dimensions, thermal conductivity, and documented restoration costs underscore the role of local context in determining material viability. The study highlights key usability factors, including availability, durability, workability, environmental impact, and socio-cultural value. It concludes that traditional building materials remain viable for sustainable construction and heritage preservation, provided that conservation strategies are tailored to local realities. By reinforcing the importance of traditional knowledge and material science, the research contributes to the discourse on sustainable heritage architecture and offers insights for policy makers, architects, and conservationists working in arid and semi-arid regions.