In this paper a method of measuring object diversity, based on an application of a diversity index, is proposed. The problem offinding an appropriate measure of diversity is formulated as a projection from afinite-dimensional space onto a one-dimensional space. In such an approach, the measure of diversity is expressed in the form of a one-dimensional descriptor (index). Properties of the index, such as exactness of measurement of diversity and examination of the behavior of the index as a function in three-dimensional space, are described and illustrated. A procedure f o r normalizing the index and identifying characteristic points f o r the interpretation of the results is proposed. The utilization of characteristic points and a fuzzy set theory to distinguish the levels of diversity is also proposed. A n application of the method to measure the diversity of the housing stock in local areas of some Australian cities is presented. A further application of the normalized diversity index, that is, to find a relationship between housing diversity and population characteristics in particular areas, is also developed.