Indonesia lies on the equatorial line that is rich in sunlight throughout the year, sothat natural lighting is an important aspect of buildings. The building planners (architects) should consider the optimal use of natural lighting through openings in the building and in addition must conform to visual comfort standards. A good building must meet the principles of sustainability through the concept of green building. The observation of the case study, teh building of Rusunawa Jatinegara Barat Jakarta, shows that the level of illumination of each floor level is different. The higher the floor level, the greater the chances of sunlight entering the room through openings and the higher the illumination rate. Illumination levels that exceed natural lighting quality standards contribute to the visual discomfort of glare. Glares that occur in some tower units result in residents closing the openings conventionally and prefer to use artificial lighting throughout the day, causing the building not energy efficient, which means it does not support the concept of sustainability (green building). Therefore, it is necessary to design a proper opening in the next planning stage, which can be used as a design recommendation that meets the criteria of visual comfort standards. This study aims to evaluate natural lighting in residential units of Rumah Susun Jatinegara Barat. Quantitative research method is done by using IES-VE v5.3.1 software, where one of the simulation tool, that is radiance, can calculate the level of illumination of natural lighting in unit's area. The sample was chosen based on purposive sampling method with consideration of unit placement and floor height.