Designing with earth, reeds and straw for contemporary sustainable welfare architecture

Earth, straw, reeds and wood are the main natural building materials in many parts of the world. These materials have several positive properties including thermal resilience, climatic adaptive performance, and a lower-impact on the environment, which have been tested and proven in vernacular architecture over the years. In contemporary practice there is still a very limited use of vernacular natural materials. Conventional industrial materials dominate, even when traditional materials offer the same quality with the same cost and performance, if not sometimes better. This study is part of a semester-long course in sustainable architecture for students completing masters. It will present students’ hands-on experimental work for 8 different wall sections using wood, earth, reeds and straw in several combinations. The wall sections are built at a 1:1 scale and tested in a living laboratory environment consistent with the Danish climate. Energy performance and U-values were mathematically calculated to assure compliance with Danish energy-efficient building standards. Life cycle costs and a life cycle analysis were calculated as they were of prime concern. Thermal performance, time lag and heat coefficient values were modeled and simulated as well. Students also had to consider water and fire resistance and the formation of moisture in their design proposals. The study proved that using traditional materials can provide equivalent thermal performance outcomes as contemporary industrial materials while producing better indoor air quality and a lower impact on the environment through their minimal carbon footprint (based on cradle-to-cradle calculations). The paper concludes that there are diverse challenges that still hinder the use of vernacular thinking in contemporary practice.