Ambient and indoor air pollution in China contributed to more than 1 million deaths in 2017, of which more than half were attributable to the residential sector, particularly the massive and inefficient use of solid fuel for heating and cooking in rural households. To address persistent severe air pollution, the Chinese government launched a clean heating campaign in 2017 to replace millions of solid fuel stoves with various clean heaters. However, replacing solid fuel stoves with clean heaters usually increases household heating costs. One of the major reasons for high heating costs, which has been largely overlooked in the current clean heating transition, is the poor thermal performance of Chinese rural residential buildings. We provide the first attempt to examine energy-saving potentials, costs, benefits, adoption strategies, and CO2 emission mitigation potentials of improving building envelope efficiency in Chinese rural residential buildings.