Waste heat, waste material, and waste water are estimated for the production of glass sheets and aluminum frames for architectural window systems. The purpose is to compare the wasted energy and matter in the production process and the heat loss through the window systems. Raw materials, fossil fuels, and fresh water are inputs, while waste heat, waste material, and waste water in addition to the products are outputs. Waste heat of 16.9 MJ versus 502.5 MJ, waste materials of 0.7 kg versus 5.4 kg, and waste water of 0.05 m(3) versus 0.37 m(3) are given off in the production of a glass sheet of 1 kg versus an aluminum frame of 1 kg. A comparison of a single glazed window and a double glazed window was made in terms of the waste heat at the production stage and the heat loss through the windows. It was found that the sum of the waste heat and the heat loss in the case of a double glazed window becomes smaller than in the case of a single grazed window within the first winter season in Tokyo.