Traditionally, buildings in the Inner Himalayan valleys of Bhutan were constructed from rammed earth in the western regions and quarry stone in the central and eastern regions. Whilst basic architectural design elements have been retained, the construction methods have however changed over recent decades alongside expecta-tions for indoor thermal comfort. Nevertheless, despite the need for space heating, thermal building performance remains largely unknown. Furthermore, no dedicated climate data is available for building performance assess-ments. This paper establishes such climatological information for the capital Thimphu and presents an investiga-tion of building physics properties of traditional and contemporary building types. In a one month ﬁeld study 10 buildings were surveyed, looking at building air tightness, indoor climate, wall U-values and water absorption of typical wall construction materials. The ﬁndings highlight comparably high wall U-values of 1.0 to 1.5 W/m²K for both current and historic constructions. Furthermore, air tightness tests show that, due to poorly sealed joints be-tween construction elements, windows and doors, many buildings have high inﬁltration rates, reaching up to 5 air changes per hour. However, the results also indicate an indoor climate moderating effect of more traditional earth construction techniques. Based on these survey ﬁndings basic improvements are being suggested.
The Authors. Published by Elsevier Inc. on behalf of International Energy Initiative. This is an open access article under the CC BY license
Mark F. Jentsch a,* , Christoph Kulle a,TobiasBodea,ToniPauera, Andrea Osburg a,Tenzinb, Karma Namgyel b, Karma Euthra b, Jamyang Dukjey b, Karma Tenzin b