Lightweight concretes with thermal insulation properties and good compressive strength can be produced by the replacement of normal aggregate of cement mixture with low-density materials. In this study, sand in a cement mixture has been replaced totally with silica aerogel powder as well as replacement of cement with fly ash. Furthermore, nano silica and silica-fume were added and incorporated into the concrete matrix. The most obvious finding to emerge from this study was that a lighter sample with no sand contributed to the lowest thermal insulation reduction by 58% of the reference sample and reduction in density to 22.8%, with reduced compressive strength of 27.11 MPa at 28 days. Obtaining of a lighter concrete by using aerogel, a chance of reduced building cooling and heating energy consumption and enhanced indoor comfort with the reduction of mold and condensation on buildings wall was obtained.