Using material flowcharts on wood and carbon, the study was made as follows:
1) With flowcharts developed on building-related woody waste and forest wood residues, the current status was analyzed.
2) Through field survey, regional supply-demand imbalance was revealed as a major obstacle to of wood residue utilization.
3) Subsequently, carbon flow analyses resulted in different carbon evaluations depending on whether fixed carbon was considered or not, but either case showed utilization of wood residues has substantial effects on fixed-carbon increase.
4) The study concludes that utilization of wood residues can help bring about a lower carbon society.