A formalism for a general theory of subjective multi-domain indoor-environmental quality perception

People can be asked to report their subjective appraisal of specific aspects or domains of indoor-environmental quality (IEQ) including thermal, visual, acoustic, and indoor air conditions in buildings. Specifically, subjective evaluations of these individual IEQ domains as well as the overall IEQ assessment can be obtained via constructs such as “satisfaction” or “comfort”. People can be also asked to provide their overall (or general) appraisal of IEQ. In this context, the present contribution poses the following question: Can people’s assessment of overall IEQ be predicted based on their assessments of individual IEQ aspects? This paper presents a theory and a related formalism to derive people’s overall satisfaction level with IEQ based on the application of weights to their domain-specific IEQ appraisals. Specifically, the theory postulates that domain-specific evaluations of IEQ conditions influence the resultant overall IEQ evaluation in a non-linear fashion, which cannot be fully captured via fixed weight assignments. As such, the weights are suggested not to be constants, but depend on the relative strength of the stimuli in a multi-domain indoor-environmental exposure situation. The paper outlines the concept behind and the elements of this “variable-weights” theory of subjective multi-domain IEQ perception and provides a formalism toward its operationalization. A path to the formalization of the theory is outlined and a preliminary empirical test of its performance is presented.