Three-dimensional concrete printing (3DCP) is one of the new emerging techniques in construction sector. By focusing on the development of more efficient thermal insulation materials and techniques, 3DCP contributes to the creation of sustainable and energy-efficient building walls. In this direction, the primary objective of this study aims to explore two different lightweight aggregate (expanded polystyrene (EPS) bead and rice husk (RH)) that minimize the transfer of unwanted heat across the building envelope, thereby reducing the energy demand for maintaining desired indoor temperatures. At first, the thermal performance of the 3D printed solid and hollow slabs was evaluated and found that hollow slabs underperform with higher inside surface temperature (4.326 ºC) compared to the 3D printed solid slab. To improve the thermal performance of hollow slabs, lightweight concrete was prepared as infill material with three different volume fractions (20, 40, and 60%) of EPS beads and RH replaced with normal aggregate (sand) and binder (fly ash). With increase in the replacement level, both EPS- and RH-infilled concrete slabs were found to show notable decrease in the inside surface temperature. To be specific, 3D printed hollow slab infilled with EPS concrete was found to perform better as it decreases the inside surface temperature by 9 °C as compared to 8 °C for RH concrete for 60% replacement level.