A large share of the world population lives in an unreinforced masonry house. These structures are extremely vulnerable during earthquakes and the main cause of casualties. Thus, it is necessary to improve their seismic performance through retrofitting. The efficiency of PP-band meshes to increase the seismic capacity of masonry structures has been experimentally and numerically verified. These plastic straps are inexpensive, durable and worldwide available. In this paper, a methodology to design these meshes to retrofit low earthquake resistant houses is outlined.