The Potential for Light Straw Clay Construction in Japan: An Examination of the Building Method and Thermal Performance

Abstract

Light straw clay is a mixture of straw and clay used as an infill in wood framed construction to create non-load bearing walls. Light straw clay has numerous advantages: Consisting of straw and clay, the raw materials are locally available throughout most of Japan. Light straw clay′s relatively low thermal conductivity provides good thermal insulation, which reduces energy use and CO2 emissions due to heating and cooling. The tools and technology needed to construct light straw clay walls are relatively simple and commonly available. And lastly, upon deconstruction, the walls can safely decompose without becoming landfill. There are relatively few non-commercial insulation materials consisting of renewable materials. The purpose of the present study is to evaluate the potential for light straw clay in Japan, including an investigation of the building method, thermal conductivity and overall heat transfer. The building method was found to take more time than conventional construction, which in turn increases labor costs. The mean thermal conductivity of the actual light straw clay insulation was 0.067W/mK. The heat transfer coefficient for a cross section of the insulated wall was 0.531W/m2K.

Keywords

• light straw clay
• thermal conductivity
• heat transfer