In order to investigate the influence of these boundary conditions on the force-deformation behaviour of URM walls, six quasi-static cyclic tests were performed. Different boundary conditions were simulated by varying the axial load ratio and the ratio of top and bottom moment applied to the wall. This article presents the test results and discusses the influence of the boundary conditions on the failure mechanism and the drift capacity of the walls. In addition, the results from 64 quasi-static tests on URM walls of different heights and masonry types are evaluated. These tests confirm the influence of the boundary conditions on the drift capacity. Moreover, they show that a strong size effect is present which leads to smaller drift capacities with increasing wall height. For this reason, an empirical drift capacity equation is proposed which accounts for the moment profile, the axial load ratio and the size effect.