Buildings are large consumers of energy in all countries. In regions with harsh climatic conditions, a substantial share of energy goes to heat and cool buildings. This heating and air-conditioning lost can be reduced through many means, such as the selection of the building thermal insulation materials. The proper use of thermal insulation material in buildings does not only contribute in reducing the annual energy cost but also helps in extending the periods of thermal comfort without reliance on mechanical heating and air-conditioning. Aerogel is one of the novel insulation these years, thermal conductivities of 0.04 W/mK less can be achieved using it. The paper is concerned with a review of Microporous Aerogel for building applications. And it also provides information about their performance.