Thermal-comfort modeling has traditionally incorporated radiant effects via the metrics mean radiant temperature (MRT) and radiant temperature asymmetry. These metrics have not until recently, considered the effect of incoming solar radiation directly heating the occupants, though it significantly affects their thermal comfort. In this paper, we describe a new approach for the calculation of the hourly effective radiant field (ERF) and mean radiant temperature (MRT) for an occupant near various façade systems and office layouts. The new method uses Radiance to assess the hourly intensity of solar radiation that passes through a facade and lands on the human body. The proposed method, for commercial buildings, allows calculating with high accuracy the comfort effect of solar radiation on occupants throughout the year.