This chapter presents the results of the in-plane test campaign on masonry piers representing three different masonry typologies, assembled using vertically hollowed clay units with thin webs and shell and tested under controlled boundary conditions, with different in-plane slenderness ratios and different applied vertical loads. The use of thin web/shell clay unit masonry is becoming increasingly widespread for its good thermal and acoustic insulation performances. Clay units with thin webs/shells could be a source of weakness and brittleness when used in load-bearing masonry walls subjected to shear cyclic excitations. Pseudo-static in-plane cyclic tests on large scale walls, under controlled boundary conditions and with different in-plane slenderness ratios and applied vertical loads, have been performed. The effort of clay unit producers to implement innovative solutions regarding the energetic efficiency of masonry products leads to the development of clay units with very thin webs and shells aimed to improve the thermal and acoustic insulation properties.