【大手ハウスメーカー】本当に高気密高断熱か…？平屋の注文住宅を丸裸にしてみたin岐阜

A House Where a 5-Year-Old Cries from the Cold: Exposing the "Lie" of High Airtightness and High Insulation A home built believing the promise of "warm in winter and cool in summer." However, the reality was a harsh environment where "the floor was freezing cold and the child cried in the bathroom." In this revealing project, we visited a single-story house in Gifu Prefecture. Despite employing heat exchange ventilation and foundation insulation, why was it so cold? A professional investigation using specialized equipment revealed surprising facts. 1. The "Temperature Boundary" Revealed in the Site Survey A thermographic camera (thermal imaging camera) survey visualized the overwhelming temperature difference between the living room and the north-facing area (entrance and bathroom). Performance of Resin Sash: The surface temperature of the windows themselves remained stable at around 20℃. The Demonic North Zone: The temperature clearly dropped near the entrance and dressing room, revealing a "weakness in insulation and airtightness." Inadequate Gaskets: Cold air intrusion from near the door was identified. 2. Shocking Airtightness Test Results and the "Trap of Numbers" The airtightness test showed very good results numerically. However, this is where the pitfall of "specs-first" thinking lies. Concentration of Gaps: While there were few gaps throughout the house, the remaining gaps were concentrated around the foundation. Localized Discomfort: Cold air rushed in through tiny gaps around the entrance and bathrooms, drastically lowering the perceived temperature. Construction Blind Spot: The "joints with the foundation," which the urethane spraying contractors didn't touch, were a blind spot. 3. Why is a "High-Performance House" Cold? Three Root Causes The investigation revealed that the reason this house was cold wasn't simply due to "gaps." The insulation performance was equivalent to "Grade 4," the lowest level for modern high-performance housing. The roof and walls were not thick enough, making it highly susceptible to outside temperatures. Heating Plan Mistake: Only one 6-tatami mat size air conditioner was used for a 27-tsubo (approximately 90 square meter) space. The amount of heat from the "whole-house continuous heating" system is overwhelmingly insufficient to make the heat exchange ventilation system function properly. Ventilation path defects: The ventilation system is drawing in cold air through gaps in the foundation and carrying cold air from under the floor to each room. 2. Professional tips for recovering from a "freezing home" We provided specific advice to overcome this situation and create a home where your children can live happily. Adding air conditioners: Don't overestimate the performance; add air conditioners to ensure adequate heat output. Airtight construction focusing on the north side: Reinforce areas like the dressing room where people get undressed and the entrance area, which is an entry point for cold air, with caulking and airtight tape. Reviewing the operating method: 24-hour heating is recommended to maximize the capacity of the heat exchange ventilation system. Frequently Asked Questions (FAQ) Q: Why is it cold even though the airtightness score is good? A: Even if the score is good, if gaps are concentrated in the "foot area" or "water areas," the cold air entering from there will increase discomfort. Furthermore, insufficient insulation thickness and poor selection of heating equipment are also major contributing factors. Q: If a heat exchange ventilation system is installed, is a small air conditioner sufficient? A: No. Heat exchange ventilation is a system that "prevents existing warmth from escaping," it does not generate heat. A heating capacity (air conditioner, etc.) commensurate with the overall heat loss of the building is essential. Q: Is it possible to repair airtightness even after construction? A: Yes, it is. As in this case, even just treating visible and accessible areas such as around the entrance and underfloor inspection hatches with caulking can change the perceived temperature. #HousingPerformance #HighAirtightnessHighInsulation #AirtightnessTesting #CustomHomes #SingleStoryHomes #InsulationDefects #RoomTour #GifuPrefecture #MyHomeRegrets #HouseSupplements