Impacts on the embodied energy of rammed earth façades during production and construction stages

Rammed earth is a technique for constructing sustainable buildings, with a low energy demand encompassing the whole life cycle of buildings. Soil from the excavation can be compressed on-site to build a façade. Due to its hygroscopic and thermal properties, rammed earth façades stabilise indoor comfort, which potentially supports the minimisation of use of mechanical systems. In order to reduce the energy demand for the entire life cycle of buildings, the embodied energy must be taken into account. Databases, such as the German Ökobaudat, provide data for a life cycle assessment (LCA). For rammed earth, aggregated data at product stages A1-A3 are provided, but transport, which is included in stages A2 and A4, and construction processes at stage A5 are barely documented. Thus, the energy demand for transport, production, and construction of two rammed earth façades was measured. The results are documented in this paper, which provides a more thorough understanding of the entire building process and helps to expand the database. One can conclude that transportation has the largest impact on the embodied energy of rammed earth façades, so it’s essential to use local material. Furthermore, the results illustrate the implication of transport on a life cycle assessment, as well as for other constructions.