Because estimating the amount of disaster waste will affect all subsequent restoration processing, it is necessary to quickly estimate the quantity and extent of disaster waste. This estimation can be accomplished using remote sensing data with the development of a method for extracting detailed information buried in a one‐pixel mixed class (‘mixel’). In a previous study, the use of RapidEye data observed during, before and after an earthquake, we proposed methods to extract detailed information buried in the mixel and classify land cover information. Moreover, we proposed methods of estimating disaster building domain and disaster building numbers. However, the amount of disaster waste has not yet been estimated. In this paper, we propose such a method using the results of estimating disaster building numbers. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.