The trade-off between density and other objectives: A re-examination of planning norms

Abstract

Residential density (dwelling units per area) affects the quality of life in urban environments in many direct and indirect ways. Determining the optimal level of density requires in each case, balancing all the relevant factors and influences, and should depend on the preferences of the potential residents and their financial resources. A residential neighborhood has many characteristics. Usually people trade off one characteristic against another. For instance: people can trade off density against cost or accessibility against space. The aim of good planning is to find the combination of characteristics that will give maximum level of satisfaction to the residents of a neighbourhood subject to the limitations of their budgets. Density standards should, therefore, be adapted to the preferences of the potential residents and their preferred compromise between the various attributes of their environment. To make things more complicated, the concept of density has many definitions, and different definitions are relevant when analysing the various effects of density. It seems that people do not perceive the gross residential density as it is measured, but are influenced by variables such as set-back distances, the percentage of building coverage and the like. Evidence is cited from an investigation in Kiryat-Gat which suggests that the perception of density is affected by other factors except the density itself. If people do not perceive the density as such but are affected by other factors, then modification of these factors is very important. If planners are to design neighborhoods according to the residents' preferences, they should have quantitative estimates of the residents' relative evaluation of these characteristics, including possible savings in the price of housing. The problems of investigating residential preferences are discussed, and examples of studies addressed to these questions are described.