Lighting Simulation is used to optimize day lighting inside the building to minimize light trespass from the building and to reduce sky glow during nights. Optimum day lighting reduces the energy required for lighting building interiors. Day lighting and outdoor views also connect the building to nature thus helping increase occupant productivity. Day light design involves a careful balance of heat gain and loss, glare control and visual quality. Shading device, light shelves, courtyards, atriums and window glazing are all the strategies employed in day lighting design. Important consideration includes the selection of building's orientation, window size and spacing, glass selection, reflectance of interior finishes and locations of interior walls.

Proper day lighting not only saves electrical energy used by artificial lighting but it also reduces the energy required for running the air conditioning system. Proper glazing design helps reduce the heat energy coming inside the building but at the same time allows for adequate day lighting. Light pollution reduction involves strategies of reduction in light trespass from the building. Minimum light pollution provides better visual comfort and improved visibility resulting in aesthetically pleasing environments. This also helps in improving night time visibility through glare reduction and also reduces development impact on nocturnal environment.