Survey: 41.0% Have Felt Their Home Environment Affects Health, While 81.0% Have Not Considered the Link Between Insulation and Health Risks

NEXER and Jin Koumuten Co., Ltd. conducted an online survey of 500 men and women across Japan on the relationship between housing and health. According to the survey, 41.0% of respondents said they had felt that their home environment affected their own or their family’s health. The most common situation was “feeling unwell due to summer heat,” cited by 44.4%. This was followed by “being concerned about mold or humidity” at 40.0%, and “being more likely to feel unwell due to winter cold” at 39.0%. Items related to indoor air quality and allergies, such as poor ventilation, effects on sleep quality, and sneezing or rhinitis caused by house dust, were also cited by more than 20% of respondents. Regarding sick house syndrome and health problems caused by chemical substances used in housing materials, only 5.4% said they knew the issue in detail. Meanwhile, 50.0% said they had heard of it, and 44.6% said they did not know about it. While more than half of respondents were aware of sick house syndrome to some extent, few had detailed knowledge. On indoor air quality, 40.8% said they pay attention to ventilation, humidity, mold, house dust, and related issues in daily life. Among those who take measures, the most common action was “ventilating frequently,” cited by 68.6%. This was followed by “cleaning frequently” at 43.1% and “using an air purifier” at 35.3%. The results suggest that most people rely on basic measures such as ventilation and cleaning, while fewer use appliances or measuring devices for more advanced control. In contrast, only 19.0% said they had considered the relationship between a home’s insulation performance and health risks, while 81.0% said they had not. Among those who had considered it, the most common triggers were “winter cold felt severe” and “seeing news or information about heat shock,” both at 65.3%. Other reasons included concern about family members’ health at 30.5% and concern about cold sensitivity or allergies at 24.2%. Respondents also mentioned real-life concerns such as mold in bathrooms, itchy eyes and sneezing in certain rooms, condensation on windows, the burden of cold environments on the heart, and measures against heat shock when bathing in winter. The survey suggests that many people become aware of the connection between housing and health not through prior knowledge, but after they or their family members experience physical discomfort. Overall, the survey found that around 40% of respondents had felt that their home environment affects health, while most had not connected insulation performance with risks such as heat shock, cold sensitivity, or worsening allergies. When choosing a home or considering renovations, the report suggests that people should look beyond appearance and floor plans and also consider insulation performance and indoor air quality to create a healthier living environment.