Pilot Survey for the Conservation of Traditional Masonry Houses in Bhutan
From the scientific research aspect, the Tokyo National Research Institute for Cultural Properties (TOBUNKEN) provides technical support for the value evaluation and enhancement of heritage buildings to the Department of Culture (DoC), the Ministry of Home and Cultural Affairs of Bhutan, which aims to expand the scope of heritage conservation to all historic buildings, including traditional houses. While we have been forced to implement cooperation projects online since January 2020 due to the worldwide COVID-19 pandemic, TOBUNKEN agreed with the DoC to resume joint surveys in Bhutan, following the significant easing of travel restrictions in Japan and Bhutan from July and September onward, respectively. From November 5th–15th, 2022, TOBUNKEN dispatched four staff experts, including an expert from the Nara National Research Institute for Cultural Properties.
The mission targeted the traditional masonry houses found in the eastern part of Bhutan. The purpose was to recognize and analyze the fundamental features of settlements and buildings in the region as the preliminary stage of the comprehensive scientific survey, which will serve as the basis for appropriate heritage conservation and development. Effective survey strategies were also examined in the mission. The on-site survey covered Trongsa Dzongkhag, Bumthang Dzongkhag, and the surrounding area, located in the central-eastern part of the country, which is relatively easy to access from the capital city of Thimphu. Measurements, photogrammetry, and interviews with locals were conducted in villages and houses preselected by the Division of Conservation of Heritage Sites (DCHS) of the DoC, based on the governmental archive and information provided by Dzongkhags. We found that the region had its own distinctive village forms. For instance, Trong and Korphu, located in the rugged mountainous area in the southern part of Trongsa Dzongkhag, are particularly unique as their houses are built in rows along a ridge, giving them merchant town-like appearance despite them being farming villages. In addition, while almost all houses in Trong are masonry structures, those in Korphu are both masonry and rammed earth structures, and rammed earth structures retain their older form. In other houses we surveyed, some were originally built in rammed earth, and later expanded or modified in stone. This suggests that, at least in the region surveyed this time, the structural manner of traditional houses shifted from rammed earth to masonry. We also found some masonry houses that have a very complex series of expansion and modification, and there is a possibility that the frequency of modification is generally higher in masonry structures than that in rammed-earth structures. Regarding the survey method, photogrammetry proved to be efficient and very useful in recording the masonry house, which shows random and complex patterns with natural stones and has many distortions in its shape.
After the on-site survey, a Memorandum of Understanding (MoU) for the cooperation in the conservation of architectural heritage was signed at the DoC headquarters, Thimphu, and a meeting was organized with the DCHS to discuss the results of the survey, as well as the prospects and needs of the Bhutanese counterparts. In the future, we expect to develop more on-site surveys and research activities targeting masonry houses in eastern Bhutan in close collaboration with the DCHS.