Taking into consideration the seismic vulnerability of older buildings and the increasing need for reducing their carbon footprint and energy consumption, the application of an innovative system is proposed and investigated, which is based on the use of textile reinforced mortars (TRM) and thermal insulation as a means of combined seismic and energy retrofitting system of existing masonry walls. Medium scale tests were carried out on masonry walls subjected to out-of-plane and in-plane cyclic loading. The following parameters were investigated experimentally: one-sided versus two-sided insulation and/or TRM jacketing, placement of the TRM outside the insulation or in a sandwich form (over and under the insulation), as well as the displacement amplitude of the loading cycles. Additionally, numerical modeling was carried out, to predict the experimental results. From the results obtained in this study the authors believe that TRM jacketing may be combined effectively with thermal insulation, increasing the overall strength and energy efficiency of the masonry panels in buildings.