Assessment of Visual Privacy and Its Change in Dense Urban Environments

Great efforts have been made to evaluate the residential environment under the urban expansion, while residential visual exposure relating to privacy is rarely involved. This paper introduces a quantitative indicator, namely, the Potential Visual Exposure Index (PVEI), to assess visual privacy by measuring the damage of potential visual incursion from public spaces and neighborhoods in high-density residences. To validate the proposed PVEI, a case study with a neighborhood located at the center of Kowloon, Hong Kong, was evaluated. Moreover, the PVEI change of each residential opening was further detected and calculated by considering a newly built dwelling. The results were under the common-sense notion that lower floors are subjected to poor visual privacy, and privacy is relatively well-preserved in upper floors in a building. However, residents of middle floors may suffer the worst circumstances concerning visual privacy. With the involvement of the newly built dwelling, significant PVEI changes can be found on the north of the neighborhood, where the newly built dwelling is located. The PVEI can be a useful indicator to assess visual privacy for optimal control of new buildings in the early design stage.