This paper aims to propose an approach to automated lighting layout system in indoor space in the perspective of auto-generation of design alternatives. Lighting environment is one of the most important factors in the domain of interior design. Well-designed lighting environment enables occupants to perform their actions safely. Furthermore, it supports occupants? psychological stability. In existing lighting design process, difficultness is that the process is usually depended on experts? experience and it is performed manually based on 2D CAD drawings. Thus, it tends to be time-consuming to create alternatives and error-prone to meet standards in the early phase of design. In this regards, as the way to create alternatives of lighting environment based on quantitative data, this paper suggests an approach to auto-layout system of lighting objects in indoor space in BIM plug-in form. The entire system consists of three major parts: 1) derivation of properties from BIM object and user parameter, 2) calculation of illuminance and the number of lighting fixture according to derived properties for creating alternative which meet standards and 3) suggestion of automatically generated alternative, reports on result value associated with created alternative and visualization of created alternative. In short, this paper proposes a way to create design alternatives of lighting design intuitively using properties included in BIM model by auto-layout of lightings. And it also includes provision of output data associated with result reports from performance analysis.