Developing a simplified parameter for assessing view obstruction in high-rise high-density urban environment

View is a key factor that influences property price. Previous studies represent view either by simple pictorial description of a scene, or by rather sophisticated mathematical methods. Both hinder proper allocation of a premium for different view obstruction levels for high-rise high-density urban environments. View obstruction level and the applicable premium are useful information for stakeholders of the property market for making optimum decisions. Accordingly, there is a need to develop a simple parameter for assessing view obstruction level. While view is difficult to define, reference is made to law cases which often settle view disputes by the extent of daylight obstruction. Shading mask is typically used to assess availability of daylight outside a residential unit and hence is an ideal parameter for assessing view obstruction. Computation of shading mask values (SMK) is a very complex task that needs meticulous site surveys, 3D drafting skills, and computer simulations. They are too effort intensive for stakeholders. This paper summarizes the relevant considerations and the case studies conducted to establish the average angle of unobstructed sky (θ) as a simple parameter to represent mean SMK for assessing view obstruction. Correlation analysis of mean SMK of 708 case study residential units determined by the detailed computer simulation method and the corresponding angle of unobstructed sky showed that the latter can be used to assess view obstruction adequately close to simulation predictions. Given average angle of unobstructed sky can easily be determined based on the geometrical primitives of a residential unit, this can enable future allocation of a premium for different view obstruction levels for stakeholders.

► Review of transaction records indicated that view obstruction level affected property price.
► A simple and yet scientific indicator was developed based on shading mask simulations.
► The simple indicator provides a precise, continuous and objective measure of view obstruction.
► The indicator enables future allocation of a monetary value for different view obstruction levels.