For the analysis of centric and double-eccentric wall compression tests, a comprehensive database of different highly thermally insulating clay unit types is being compiled for the first time. The objective of the analysis is, on the one hand, to characterise the load-deformation behaviour of highly thermally insulating clay unit masonry and, on the other hand, to analyse the resulting stress distribution at the cross-section level. In addition, the influence of the increasing load inclination angle with decreasing test specimen slenderness is also shown. With regard to the wall compression tests under double-eccentric loading, the effects caused by the load inclination become obvious and lead to an average reduction of the load-bearing capacity of 41% compared to the centric compression tests. Furthermore, an opposite effect can also be observed with regard to the generally known interaction between decreasing specimen slenderness and increasing load-bearing capacity. According to this, lower load-bearing capacities result with constant eccentricity and decreasing slenderness, so that a back calculation to a uniform slenderness ratio with the relevant normalisation functions is not possible. The reason for this is due to the linearly increasing load inclination angle and the resulting increasing shear stress within the transverse webs.