Overheating, glare, and high-energy demand are recurrent problems in office buildings in Santiago, Chile (33°27’S; 70°42’W) during cooling periods. Santiago climate is warm and dry, with high solar radiation and temperature during most of the year. The objective of this paper is to evaluate the thermal and daylighting performance of office buildings transparent façades composed of three different complex fenestration systems (CFS). Each CFS contains a different external shading device (ESD): (1) external roller, (2) vertical undulated and perforated screens, and (3) tilted undulated and perforated screens. The study was carried out by in situ monitoring in three office buildings in Santiago, Chile. Buildings were selected from a database of 103 buildings, representing those constructed between 2005 and 2011 in the city. The monitoring consisted of measuring the short wave solar and daylighting transmission through fenestration systemsby means of pyranometers and luxometers, respectively. This paper shows measurements that were carried out during summer period. A good performance is observed in a building with the external roller system. This system—applied to a northwest façade—shows a regular and high solar and daylighting control of incoming solar radiation. The other two ESD systems evidence a general good performance. However, some deficiencies at certain times of the day were detected, suggesting a non-appropriated design.