Design builder is the first comprehensive user interface to the EnergyPlus dynamic thermal simulation engine. Building geometry can be created in the Design Builder’s OpenGL modeller or imported as a gbXML file from an architectural modeling program. Moreover,Design Builder can be used to evaluate a range of facade options for the effect of energy use and visual appearance. Energy Plus can calculate heating and cooling loads using the ASHRAE-approved ‘Heat Balance’ method [24]. Figs. 2 and 3 show an actual photograph and the Design Builder model of the studied green building respectively.