Abstract
Glazing is considered as a preferred solution for the buildability, aesthetic, and comfort of commercial buildings since glass cover can protect occupants from external environmental conditions, ensure the light transmission, and provide view and ventilation. At the same time, in the context of climate change and global warming, the use of renewable solar energy, such as solar and wind power, are encouraged to be utilized. Specifically, solar energy has become a renewable energy source that is clean and endless, at reasonable cost, to contribute to energy security as well as ensure sustainable development. Therefore, the study proposes a method for supporting the decision making in installing solar panels on vertical glazing façades of the building in the worst case that the remaining radiant energy from the sun was only transferred to the inside of the building. The Life Cycle Assessment and the Life Cycle Costing methodologies are applied to consider both environmental and economic aspects. The proposed method can (1) minimize the project cost (including initial investment cost and operation cost) during the building lifetime; (2) analyze the optimal budget to minimize the total life-cycle cost of the building over its lifespan and maximize the renewable energy generated from the sunlight entering buildings in different directions. The results show that with different initial investments, the investor will have a corresponding solution for choosing an optimal installation ratio for each type of glass combined with the installation ratio of solar panels on the façades to reach the optimal energy efficiency as well as environmental performance. This study is beneficial for investors in selecting energy-saving solutions in office buildings in the beginning phase of the project life cycle.