The Relationship Between Ventilation and Building-Related Symptoms in Modern High-Performance Japanese Houses: A Cross-Sectional Study Using Building-Specification Data

Ventilation plays a key role in maintaining indoor air quality and reducing building-related symptoms (BRSs). Although prior studies suggest that ventilation volume and system type may influence BRSs, few have examined their combined effects in residential settings. This cross-sectional study investigated associations between ventilation volume, system type, and BRSs among 3970 residents of newly built detached houses in Japan. Data were collected in two waves in 2023, and the ventilation volume per floor area and per person was calculated from building specifications. BRSs were assessed using the MM040EA Sick House Syndrome questionnaire and analyzed using binary logistic regression stratified by system type. In air supply and exhaust systems, higher ventilation volume per person was linked to a lower prevalence of general symptoms (OR = 0.46). In exhaust-only systems, greater ventilation volume was positively associated with mucosal irritation symptoms (OR = 1.60). These findings highlight the complex relationship between ventilation and health and emphasize the importance of system type. Although air quality parameters were not measured directly, the results provide evidence based on building specifications, thereby offering insight to refine building codes, guide post-occupancy assessments, and inform preventive public health policy.