Research on the environmental performance of a natural material wooden house

In this study, we examined the advantages of houses that use a lot of wood and natural materials and that also have breathable walls. There is insufficient research literature concerning the characteristics of effects obtained by using substantial quantities of wood for interiors. Typical Japanese modern houses have a damp-proof membrane but this risks being damaged during the tenure of residents or by earthquakes. Breathable walls do not have such a damp-proof membrane. We measured the environmental performance (indoor thermal environment, thermal environment and humidity in walls, and energy consumption) of four houses that use large amounts of wood, with each house using approximately 1.5 times the amount used by a typical wooden house. Results for one of these houses using large amounts of wood, even the room that was not air conditioned was most stable in terms of relative humidity, and 73.1% of measurements were classified as being within the central range of humidity. And the humility inside the wall was low enough to avoid the mold growth. From the viewpoint of energy, generally theses houses consumption of energy were smaller than the national average, but one was bigger because of the size of family and neighborhood circumstances.