Abstract: Visibility has great influence on perception. The physical attributes of the built environments influence the way people perceive it and impact their wellbeing and behavior in their private spaces and in the public realm. Previous research has confirmed that the comparative volume of visible space can indicate the comparative perceived density. Hence, a larger volume of free space would be strongly associated with a lower perceived density [1]. At the same time peoples’ willingness to pay for a view emphasizes the influence of view on perception [18] [19]. The integration of quantitative models that measure visibility in the built environment [2] [3] [13] with qualitative evaluation of visible view would make a comprehensive model. Such an integrated model would come closer to accurately predict human perception of space. This paper is presenting an ongoing research aiming at developing an integrative model combining quantitative and qualitative information of the visible space to predict the human visual perception of space. Two experiments aiming at defining the impact of variables in the visible view on the perceived density are described and their outcome is presented. Relative impact that is being defined by the participants is introduced as a possible ‘view index’. This ‘view index’ could be integrated in the 3D Line Of Sight (LOS) visual analysis [12], quantifying the volume of visible space and distances from view-point to target and surrounding view. This quantitative/qualitative integrative model may suggest quantifying perception. The experiments were carried out in a visualization lab enabling immersion of the participants in a virtual reality projected to them. The experiments groups included over a hundred participants each. Every participant was asked to rank the perceived density and visual privacy in a number of assemblies of views projected. These experiments provided a significant step towards a comprehensive view evaluation. An extended set of experiments will make the foundation for a reliable ‘view index’ to be implemented in the 3D LOS analysis as weighted views. The final section of the paper is referring to the implications of internal view on the perceived density and visual privacy focusing on small apartments. In this case the external view was very similar to keep the participants focus on the internal geometry and arrangement of space. The LOS 3D visual analysis and evaluation for interior space layout was presented and demonstrated on alternative dwelling units. Assessment based on experiments with participants immersed in virtual reality environments is suggested as future experiment. The results of this research have shown its potential contribution for professional users, such as researchers, designers and city planners, at the same time as being easily used by non-research professionals such as city dwellers, contractors and developers.