AbstractOne of the effective ways to improve the energy efficiency of buildings is the use of thermally efficient materials in the production of various building enveloped elements such as wall panels. With the increasing sustainability awareness in the construction industry and the use of cementitious materials being the most used construction materials, eco-friendly materials such as expanded glass can be utilized as lightweight aggregates to produce lightweight mortars for the construction of these elements. The novelty of this work is the results that have been obtained from the evaluation of mortars designed for the production of lightweight thermal-efficient wall panels using expanded glass as aggregates. Various proportion of expanded glass was used in the production of mortars to determine their influence on the properties of the mortar. The properties investigated are flow, thermal conductivity, compressive strength, void content, absorption, drying shrinkage, and resistance to alkali-silica reaction. Ultrasonic pulse velocity test was also utilized as a nondestructive test to assess the mortars. The findings from this study showed that it is viable to produce lightweight thermal-efficient mortars using expanded glass. The thermal conductivity of the mortars was reduced up to 78.4% when the cement to expanded glass ratio increased to 1∶5. Despite the reduction in compressive strength as a result of the presence of the expanded glass, these mortars still possess acceptable properties for the production of wall panels.