As the heights of high-rise buildings increase, their building area and elevation area also increase, consequently increasing their yearly energy consumption. Energy efficiency has become an even more important issue, especially when glass is used for a building’s exterior. In this study, the life-cycle cost (LCC) of the exterior glass of high-rise buildings was analyzed from the perspective of energy efficiency and CO2 emissions. First, the LCC was analyzed according to changes in the selected types of glass. Reflective + Low-E (Type 1), double Low-E + Argon (Type 2), and triple Low-E + Argon (Type 3), which satisfy green building certification criteria and were used in the past for high-rise buildings in Korea, were selected as the exterior glass types. These types of exterior glass were applied to a case building and compared with the Low-E glass that was the existing glass type of a case building. The economic benefit of selected glasses for 40 years was greater in the order of Type 1, Type 3,...