2014 年 10 巻 3 号 p. 287-298
Objective. Modern wooden houses are constructed from various materials, some of which result in high CO2 emissions during factory production. We have to clearly understand the environmental impact of modern wooden houses. Most researchers focus only on CO2 emissions from energy consumption in a household after construction. There is little research focused on the CO2 emissions from actual home construction. Most researchers in Japan calculate CO2 emissions using construction material measurements from housing blueprints. However, these values are not accurate. These inaccuracies stem from the difficulty in calculating the total weight of construction materials from blueprints. This leads to a difference between the weight based on actual measurements and the estimated weight based on calculations. We measured all weights of the construction materials and waste. We chose four target houses: one high-foundation wooden house (House A), two two-story wooden houses (Houses B and C) and one three-story wooden house (House D). We compared the weight of construction materials and waste between these four houses. Next, we calculated CO2 emissions using the weight in construction materials we measured.
Results and Discussion. We obtained the weight of four houses, accurate data of construction material and waste. The number of different construction materials used for the target houses was between 840 and 1525. House A’s weight per floor of construction materials and waste were 997.4kg/m2 and 12.9kg/m2, respectively. House B’s weight per floor of construction materials and waste were 751.5kg/m2 and 14.2kg/m2, respectively. House C’s weight per floor of construction materials and waste were 707.1kg/m2 and 24.9kg/m2, respectively. House D’s weight per floor of construction materials and waste were 725.0kg/m2 and 24.3kg/m2, respectively. We compared the weight in construction materials per construction area for every job type. Most of these values varied because of the differences in house specification. The four values of interior finish work were close. The amount of CO2 emissions due to construction materials could then be calculated depending on the exact weight.
Conclusions. We clarified the actual weight in construction materials and waste for the four houses. We were able to calculate CO2 emissions based on the actual weight. In order to more fully understanding, we must now gather more data from other construction companies.