The aim of this experimental study is to develop high strength, lightweight concrete mixture suitable for 3D printing in construction. This work investigates the effect of replacing normal aggregate either partially or totally with expanded perlite aggregate. This material allows for better thermal insulation properties, thus decreasing the energy usage within the life cycle of the concrete structure. Expanded perlite aggregate was used in concrete by 20 vol.-%, 40 vol.%, 60 vol.%, 80 vol.-% and 100 vol.-% in replacement of the natural aggregate. Material characterization tests of compressive strength, flexural strength, and thermal conductivity were carried out for six concrete mixtures. The proposed concrete mixture, which has 100% of expanded perlite aggregate achieved reduction percentage of thermal conductivity around 62% (0.69 W/mK) relative to normal weight concrete the mixture has a compressive strength of 42 MPa at 28 days. This mixture is appealing for 3D printing in 3D concrete printing as it reduces the environmental impact of the built environment by improving the thermal insulation and decreasing the energy consumption during building operation phase.