This article was published in the journal, Building and Environment [© Elsevier Ltd.] and the definitive version is available at: http://dx.doi.org/10.1016/j.buildenv.2009.01.007Suitable experimental methodologies for determining the hygrothermal properties of stabilised rammed earth (SRE) materials have been presented along with comparative experimental data for three different SRE mix designs with parametric analysis of the influence of these variables on material function. Higher bulk porosity corresponds to reduced volumetric heat capacity (C), but increased sorptivity (S) and vapour permeance (W). Since bulk porosity and void size distribution (VSD) are interdependent variables, it follows that for constant particle size distribution (PSD) and compaction energy an increase in porosity results in an increase in the mean pore radius, for a material. This explains why the magnitude of liquid/vapour transfer (S and W) terms are inversely related to the hygroscopic moisture capacity, ξ since the capillary potential, Ψ will increase when the mean pore diameter decreases. The implications are that the hygrothermal properties of SRE materials can be designed and predicted by manipulating particle size distribution and compaction energy

This paper provides powerful evidence empirically demonstrating for the first time the reliability of the co-heating test. The test is widely used throughout Europe to measure the total heat transfer through the fabric of buildings and to calculate the heat-transfer coefficient (HTC; units W/K). A reliable test is essential to address the ‘performance gap’, where in-use energy performance is consistently, and often substantially, poorer than predicted. The co-heating test could meet this need, but its reliability requires confirmation. Seven teams independently conducted co-heating tests on the same detached house near Watford, UK. Despite differences in the weather and in the experimental and analytical approaches, the teams’ final reported HTC measurements were within ±10% of the mean. With further standardization it is likely to be possible to improve upon this reproducibility. Furthermore, uncertainty analysis based upon a 95% confidence interval resulted in an estimated uncertainty in HTC measurements of ±8%. This research addresses persistent doubts about the reliability of the co-heating test. Avenues to further improvement of the test are discussed. This work helps to enable the test’s wider adoption as a component of the regulatory process and thus improvements to standards of house construction.