Furie Sumai Soken Survey on Living Environments in an Era of Extreme Heat | 95.4% Experience 'Heat Stress' at Home, 'Summer Comfort' Becomes Key Factor in Home Selection

FLIE Co., Ltd. (headquartered in Chuo Ward, Tokyo), which operates the used home trading platform 'FLIE (Furie)' and provides real estate DX support services, runs 'Furie Sumai Soken,' a content initiative that investigates various topics related to housing and lifestyles. This time, we conducted an awareness survey on 'living environments in an era of extreme heat' targeting 500 individuals aged 18 and over residing in Japan.

In recent years, summer heat has intensified, with growing public attention to extreme temperatures—Japan's Meteorological Agency will designate days with maximum temperatures of 40°C or higher as 'extreme heat days' starting April 2026. Heat impacts not only outdoor activities but also daily life at home, leading to various residential concerns such as sleep discomfort, high indoor temperatures upon returning home, exposure to direct sunlight and west-facing sun, and anxiety over air conditioning electricity costs.

Therefore, Furie Sumai Soken conducted a survey to understand how people perceive summer heat and what discomforts or countermeasures they experience at home. The survey revealed that 95.4% feel stress or dissatisfaction due to heat at home, and 89.2% want to prioritize 'summer heat countermeasures' when choosing future homes. This suggests that 'comfort during summer' is becoming an increasingly important factor in home selection as extreme heat becomes the new normal.

Survey Summary

1) 95.4% experience heat-related stress or dissatisfaction at home. Summer heat is no longer just an outdoor issue but a familiar concern within homes for many people.

2) The most common situation for feeling heat at home is 'during bedtime or upon waking,' reported by 75.9%. Discomfort from extreme heat affects not only daytime activities but also sleep environments.

3) 73.0% have refrained from using air conditioning or raised the temperature setting due to electricity costs. While recognizing the need for heat countermeasures, many are struggling with the burden on household budgets.

4) 89.2% want to prioritize 'summer heat countermeasures' in future home selection. As extreme heat becomes常态化, factors such as insulation, ventilation, sunlight exposure, and air conditioning efficiency are emerging as new decision-making criteria in choosing homes.

Detailed Survey Results

First, we asked respondents whether they feel that summer heat has become more severe than in the past.

<Q1. Do you feel that summer heat has become more severe in recent years?>

・Strongly agree: 70.6%

・Somewhat agree: 24.0%

・Neither agree nor disagree: 4.2%

・Slightly disagree: 1.0%

・Strongly disagree: 0.2%

Combining 'strongly agree' and 'somewhat agree,' 94.6% feel that summer heat has become more severe, indicating that extreme heat is no longer a regional issue but a widely shared experience among residents.

Next, we asked whether respondents experience heat-related stress or dissatisfaction at home during summer.

<Q2. During summer, do you experience stress or dissatisfaction due to heat inside your home?>

・Frequently: 59.8%

・Occasionally: 35.6%

・Rarely: 4.0%

・Never: 0.6%

Combining 'frequently' and 'occasionally,' 95.4% reported experiencing heat-related stress or dissatisfaction at home, showing that nearly everyone feels discomfort from heat indoors.

While homes are meant to be relaxing spaces, during extreme heat, the impact of high temperatures cannot be completely avoided—even in air-conditioned environments. There still appear to be challenges in effectively managing indoor heat.

We then asked when people feel heat-related stress or dissatisfaction at home.

<Q3. In what situations do you feel stress or dissatisfaction due to heat at home? (Multiple answers allowed)> ※Respondents who answered 'frequently' or 'occasionally' to Q2

・Feeling heat during bedtime or upon waking: 75.9%

・Concerned about air conditioning or electricity bills: 72.1%

・Indoor temperature is high immediately after returning home: 47.4%

・Room temperature rises easily due to sunlight or west-facing exposure: 38.8%

・Want to open windows but concerned about security, insects, or noise: 37.9%

・Feeling hot while cooking or using water areas: 36.9%

・Difficulty concentrating on remote work or studying due to heat: 26.2%

・Room does not cool down easily even with air conditioning: 19.1%

・Air conditioning temperature settings don't match those of family or cohabitants: 14.9%

・Other (open-ended): 1.3%

The most common response was 'feeling heat during bedtime or upon waking' at 75.9%, indicating that extreme heat affects not only daytime activities but also sleep quality.

Next, 'concern about air conditioning or electricity bills' accounted for 72.1%, showing that heat countermeasures are not only about comfort and health but also closely tied to household financial burdens.

Additionally, responses such as 'high indoor temperature upon returning home,' 'room temperature rises easily due to sunlight or west-facing exposure,' and 'want to open windows but concerned about security, insects, or noise' were common, suggesting that home structure, location, and surrounding environment significantly influence perceived heat levels.

[Selected Open-Ended Responses]

・Difficulty managing kitchen waste (20s, residing in Kyushu)

・Feeling humid and sticky (60s and above, residing in Tokai region)

・Sweating doesn't stop after bathing (40s, residing in Kinki region)

・Bananas spoil quickly (40s, residing in Kinki region)

Open-ended responses revealed that heat impacts various aspects of daily life beyond just room temperature, including humidity, food preservation, and post-housework discomfort.

Next, we asked those who reported little heat-related stress or dissatisfaction at home about the reasons.

<Q4. What factors contribute to low heat-related stress or dissatisfaction at home? (Multiple answers allowed)> ※Respondents who answered 'rarely' or 'never' to Q2

・Home layout allows air conditioning to work efficiently: 56.5%

・Good ventilation: 43.5%

・Use of circulators or fans: 43.5%

・Use of blackout curtains or blinds to block sunlight: 34.8%

・Not excessive sunlight exposure: 30.4%

・High thermal insulation of the house: 21.7%

・Surrounded by greenery or shaded areas: 13.0%

・High-performance or heat-blocking windows: 8.7%

・Not on the top floor or upper floors, so heat doesn't accumulate: 4.3%

・Other (open-ended): 4.3%

The most common reason was 'home layout allows air conditioning to work efficiently' at 56.5%. 'Good ventilation' and 'use of circulators or fans' followed at 43.5% each.

In homes with less heat discomfort, in addition to fundamental environmental factors like efficient cooling and ventilation, daily efforts such as using circulators and fans, and sun-blocking measures with blackout curtains or blinds, also contribute to reducing heat.

Next, we asked about the locations within the home where heat is most strongly felt.

<Q5. Where in your home do you feel heat most intensely? (Multiple answers allowed)>

・Bedroom: 56.8%

・Living/dining room: 45.8%

・Kitchen: 37.4%

・Rooms with strong sunlight or west-facing exposure: 34.2%

・Toilet: 33.4%

・Top floor or above the second floor