The Detection and Calculation of Design-Weighting on Indoor Environmental Elements—Illustrated by Real Interior Design Projects

In interior design projects, homeowners’ expectations and thoughts in mind are sometimes ambiguous and hard to pinpoint. This lack of clarity can lead to disagreements between owners and designers, making it difficult for designers to receive due remuneration. At the same time, the design project always has a restricted budget. Suppose the funds could be prioritized based on owners’ preferred weight of the indoor elements, with a larger portion of the budget allocated to the most crucial elements. In that case, it can significantly enhance the owner’s satisfaction. To address these challenges, this research introduces a novel analytical and computational approach that leverages the Positive And Negative Affects Schedule (PANAS) and Heart Rate Variability (HRV) to assess homeowners’ sentiments toward various indoor elements. This method aims to determine indoor elements’ design-weighting, design sequence, and distribution of project budgets, enabling designers to understand better and meet homeowners’ genuine needs and expectations in interior design projects. The efficacy of this approach was evaluated through the analysis of three real-life residential interior design projects. Data from the PANAS emotion scale and heart rate variability (HRV) measurements of the homeowners were collected before and after project completion. The findings revealed high satisfaction among homeowners following project execution. By adjusting indoor elements, owners’ negative emotions decreased significantly, positive emotions surged, and there was an improvement in the activity of sympathetic and parasympathetic nerves, leading to enhanced physical and mental well-being. Furthermore, in-depth interviews with homeowners corroborated the effectiveness of the analytical calculation method in identifying latent negative indoor elements of concern to homeowners, thereby validating the practical utility of this approach in real-world design scenarios.