Recently wood is being promoted as a primary material used for public structures. With this promotion, the use of double-skinneDSiding (DS) is being incorporated in new buildings, and as older wooden structures are now being reinforced and reformed for continued use, DS is being incorporated in these buildings as well. We examined the efficacy of DS for maintaining a comfortable thermal environment within buildings. We used accumulated temperature data taken from our experiment location, a public school classroom environment, in the Tokyo Metropolitan area to better understand the use of DS for maintaining a comfortable temperature environment within the building.<br> For our research, we focused on the following two topics:<br> (1) Analysis of the data collected over a year at the experimental site1<br> We used an existing wooden structure that had had DS added to it. We were able to note the change in the room temperature with the addition of DS. In the summer, the inside of the DS with natural ventilation had a rate of circulation of 2027 m3/h, and with the fan, the amount of air circulation was noted as 13.1 times per hour. With DS, direct sunshine was reduced by 47.2% and helped to reduce energy consumption for cooling by 20%, and the PMV±0.5 was within the comfort zone.<br> In the winter, sunlight warmed the DS, and the warmed air was pulled into the room via the floor ventilation, and when the temperature of the DS room was compared with a room without DS, the room with DS had a temperature 5° higher. The interior wall and floor surface temperature also rose by the vents installed in three areas in the room. The temperature of the inner glass surface of the DS was stable throughout the day contributing to the comfort of the room. During the nighttime, the fan could be stopped, and the use of the warmed air accumulated in the daytime was used to maintain warmth in the room.<br> During the intermediate seasons, the use of the fan to circulate the air from the natural ventilation in the DS and the floor ventilation system was incorporated. With natural ventilation of the DS, the removal of the heat of about 30W/m2 occurred, and the DS room had a 5° differentiation in temperature when compared with a room without DS.<br> (2) Examination of the Simulation Model for various environmental and climatic conditions<br> The LESCOM-mint program was used to simulate the amount of energy required to maintain a heating and air system when DS is used for a wooden structure. Actual temperature data accumulated as well as theoretical considerations were combined to gain an understanding of the air and heating neeDS according to different climatic environments.<br> We examined actual temperature measurements and the theoretical value for the summer and found both measurements to be in agreement. When considering the application of these findings for an elementary school environment, we determined that for optimal energy saving and maintenance of a comfortable environment a regular classroom should be on the southern side of the building and open space on the northern side, with DS of 1.4m placed on the southern wall. Through the use of the latest data collected from the Japanese Meteorological Agency (SDP) for Tokyo between 2010 and 2015, and the data collected from Sapporo and Naha from 2015, we have found that in areas like Tokyo, the adoption of DS is an energy-saving way to maintain a comfortable environment. In Sapporo, the warming effects and reduction in energy usage is also quite effective. For Naha, DS is effective in hot and humid environments.