A Study on Carbon-Reduction Strategies for Rural Residential Buildings Based on Economic Benefits in the Gannan Tibetan Area, China

The building sector contributes approximately half of all carbon emissions. The heating stage accounts for the largest proportion of building carbon emissions. The focus on carbon-reduction strategies in rural areas could not be copied from urban buildings due to different heating modes limited by economic factors. The Gannan region in Gansu province was selected to carry out an on-site survey on heating conditions, including the heating modes, the energy used for heating, heating fees, residents’ satisfaction with heating, and the thermal environment of the typical building. The results showed that local rural residents burnt scattered coal for heating using primitive heating stoves with low efficiency, causing low air temperatures and high heating fees. The carbon emissions generated by heating reached 5743.28 kgCO2e·m−2. Several strategies for reducing carbon emissions were proposed, considering the economic benefits limited by rural economic development. A parameter of reduced carbon emissions per investment input was proposed to evaluate the carbon-reduction strategies. The results showed that biomass was the most economical way to reduce carbon emissions. Reduced carbon emissions per investment input reached 44.19 kgCO2e·CNY−1 with energy efficiency of 50%, followed by thermal insulation design of 32.31 kgCO2e·CNY−1, natural gas furnaces of 26.08 kgCO2e·CNY−1, and air-source heat pumps of 20.27 kgCO2e·CNY−1. In addition, carbon emissions generated by biomass were 12.4% and 24% of those caused by coal and natural gas supplying the same energy. Moreover, building insulation should be increased according to economic benefits. The optimum energy efficiency was 55% in Gannan. The results provided a reference for building low-carbon heating in rural areas, which could help achieve the low-carbon goal with low investments.