This article deals the selection of optimal glazing materials for solar thermal applications with multiple performance characteristics among the twelve alternatives using the Taguchi's grey relational analysis approach. The processing parameters thermal properties, mechanical properties, optical properties, environmental and economic conditions are optimised with multi-response characteristics, including density, thermal conductivity, specific heat capacity, the coefficient of thermal expansion, notch impact strength, tensile strength, refractive index, transmittance, cost, and environment. In this investigation, twelve alternative materials and ten criteria used for material selection for the optimal design. The outcomes revealed that crystal glass has the highest grey grade of 0.588, which is the optimal glazing material among the twelve alternatives. © 2019 Informa UK Limited, trading as Taylor & Francis Group.