The buildings are responsible for more than one-third of power consumption in India. Glass is one of the significant building enclosures to control cooling loads in buildings. This paper describes how various low emissivity glasses used for building windows affect thermal performance of green energy buildings. This paper presents the thermal performance of five double glazed low reflective window glass materials such as clear low reflective glass, bronze low reflective glass, green low reflective glass, grey low reflective glass and blue-green low reflective glasses. In this paper, mud brick buildings with five low emissivity glass material windows were designed in three different climatic zones of India such as warm and humid (Mangalore), hot and dry (Jodhpur) and composite (Hyderabad). The results showed that buildings with double glazed low emissivity grey glass window are found to be energy efficient from the least heat gain point of view among all buildings studied in three climatic zones of India. © 2017 Elsevier Ltd. All rights reserved.