The potential success of a property development is commonly measured by means of a financial metric derived from exponential discounting, typically the Internal Rate of Return or Net Present Value.

Assessment of other aspects such as the environmental or social impact of property developments requires consideration of the fundamental nature of decision-making in general, the methodological constraints of a unidimensional metric and the incorporation of subjective value. 

The purpose of this paper is to place traditional viability studies in the context of recent developments in the theory of decision making and highlight potential approaches to improve the reliability of viability studies. This is done by providing an overview of salient aspects of behavioural discounting and the utility-theory based model of decision making, as well as some recent results from the neuroeconomics of choice. 

Consideration of the fundamental methodological issues involved in making decisions about property developments should contribute to the proper assessment of their longer-term return, as well as their impact on the environment and human society.