Aerogel is synthetic porous material, in which the liquid component of the gel is replaced with a gas. Aerogels have remarkably lower thermal conductivity (≈0.013 W/mK) than the other commercial insulating materials and specific acoustic properties. They also have superior physical and chemical characteristics like being translucent. Not surprisingly, they are considered as one of the most promising thermal insulating materials for building applications. Besides its applications in residential and industrial buildings, aerogel has a great deal of application areas such as spacecrafts, skyscrapers, homes, automobiles, electronic devices, clothing etc. Although current cost of aerogel still remains high compared to the conventional insulation materials, intensive efforts are made to reduce its manufacturing cost and hence enable it to become widespread all over the world. In this study, a comprehensive review on aerogels and their utilization in buildings is presented. Thermal insulation materials based on aerogels are illustrated with various applications. Economic analysis and future potential of aerogels are also considered in the study.