The main goal of the article is to compare two methods for evaluating the energy performance of commercial building facades: the BCA Section-J glazing calculator and the ETTV method. The researchers looked at a hypothetical high-rise commercial building in Melbourne, Australia to see how these methods differ in calculating energy transfer through building envelopes. They found significant discrepancies between the two methods, particularly in considering air leakage and infiltration in facade design. Improvements are needed in calculating energy performance through building facades.