The residential environment clearly affects health. For example, a previous study has established relationships between specific environmental factors and the health status of residents in detached houses. However, studies focused on apartment buildings are still insufficient. Therefore, in this study, a large nationwide questionnaire survey of residents of apartments was conducted. The residential environment was subjectively evaluated using a Japanese Comprehensive Assessment System for Built Environment Efficiency (CASBEE) tool: the CASBEE Health Checklist. The results showed that residents living in apartments who score higher on the checklist tend to have a lower prevalence of various diseases, indicating that residential environment may be an important determinant of health. Furthermore, the odds ratios for residents living in apartment buildings were lower for diabetes mellitus, hypertensive diseases, heart diseases, cerebrovascular diseases, chronic lower respiratory diseases, and inflammatory polyarthropathies compared with residents living in detached houses. These findings support the general link between the residential environment and residents' health and suggest that housing typology is an important factor.

Costs are a barrier to improving residential environments during new construction and renovation. Previous research suggests that improving residential environments may contribute to improved health. If such health effects are quantified and recognized as economic benefits (lower medical costs and income from absenteeism), increased investment in residential improvements can be expected. Therefore, this study aimed to quantify the benefits of improving health through improvement of residential environments considering individual and household attributes. The effects of residential environment improvements were quantified at the individual and household levels. Data were collected via nationwide surveys of more than 45,000 residents in 15,000 households in Japan. Health status was compared between good and poor residential environments. Results showed that an improved residential environment contributed to reducing the likelihood of the onset of cardiovascular, allergic and other diseases. The annual economic benefit of improving the thermal insulation of windows for a man living alone was 7,000 JPY for example. This study contributes to promoting residents’ health by quantifying the economic benefits of the health effects of good-quality residential environments, which then contributes to achieving Sustainable Development Goals 3 and 11.