Optimization of Natural and Artificial Lighting System Design in the Library of the Faculty of Economics and Business, Universitas Gadjah Mada

Library requires illumination condition that provides comfort used by visitors for crucial academic activities along the day. These activities require proper illumination that consump lot of energy. This paper aimps to find a lighting system scenario with optimum efficiency involving daylight-artificial lighting and full-artificial lighting in the library to obtain optimal visual performance with low energy consumption. This research examines the case study of Library of the Faculty of Economics and Business, located in Universitas Gadjah Mada, Yogyakarta. The research uses quantitative method with simulation modelling using DIALux Evo 8.1. Simulation shows that the scenario is able to meet the illumination level standards based on SNI with LPD values of 5.539 W/ m
²
for daylight-artificial lighting conditions and 6.69 W/ m
²
for full-artificial lighting conditions. Natural lighting can illuminate 32% of the total area so that the library can be categorized as a Green Building according to illuminating energy standard. The cost required for illuminating energy consumption for a year is Rp10,978,312,-which can save costs up to 25.2%.