Net-zero energy passive house and timber loam construction for healthy indoor climate: pilot project "Aktivhaus“- residential estate in Kramsach, Austria

The project “Aktivhaus“-residential estate in Kramsach focuses on (1) energetic aspects and measures to reach the “net-zero-energy-building” and (2) avoidance of low indoor air humidity in winter by using the moisture buffer capacity of loam. The latter is discussed in this paper and results are presented. This investigation includes laboratory measurements on material scale for the characterization of the used loam (sorption isotherm, diffusion resistance). Cross-validation of the building simulation model Dynbil with its hygrothermal wall model is conducted. Furthermore, the hygrothermal wall model is calibrated using laboratory experiments on component scale (hygrothermal behaviour of components in climate chambers).  The building simulation results are compared with measured temperature and relative humidity of the one-year on-site monitoring campaign in the terraced houses. Conclusions about the potential enhancement of the indoor climate are drawn depending on the area weighted moisture retention potential. An optimization with regard to loam formulation, loam area and thickness is conducted by means of simulation.