The research aims to develop a simplified calculation method for double glazing facade to calculate its thermal and solar properties (U and g value) together with comfort performance (internal surface temperature of the glazing). Double glazing is defined as 1D model with nodes representing different layers of material. Several models with different numbers of nodes or in different positions are compared and verified in order to find a simplified method which can calculate the performance as accurately as possible. The performance calculated in terms of internal surface temperature is verified with experimental data collected in a full-scale facade element test facility at Aalborg University (DK). Comparison was conducted between the simplified method and WIS software on the accuracy of calculating internal surface temperature of double glazing facade. The method is based on standards EN410 and EN673, taking the thermal mass of the glazing into account. In addition, angle and spectral dependency of solar characteristic is also considered during the calculation. By using the method, it is possible to calculate whole year performance at different time steps, which makes it a time economical and accurate tool in design stage of double glazing facade. (C) 2013 Elsevier B.V. All rights reserved.