This report makes an overview of 2D, 2,5D and 3D approaches for indoor space subdivision for the purpose of indoor navigation. The report starts with a conceptual framework for indoor space utilisation. We introduce and elaborate on the concepts of indoor space (navigable and non-navigable), agent, activity, resource and modifier. Using these concepts, we investigate navigation cases and discuss information requirements for space subdivision. Two sections make review of 2D and 3D research for sub-spacing. We classify 2D and 3D approached in three groups with respect to the subdivision (partial or complete) and the type of navigation (grid or graph), and provide analysis of the approaches against the user requirements for indoor navigation. Section 6 concludes on challenges and future developments. This research was supported by a grant (11 High-tech G11) from Architecture & Urban Development Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.