© 2021 Elsevier LtdIn this work, the influence of PCM wall utilization on the heating energy consumption of a typical northeastern Chinese rural house is numerically investigated by EnergyPlus, together with its economic and environmental impacts on carbon emissions. Simulations are conducted considering three different configurations of the PCM layer and other building materials inside the wall by taking the wall without PCM as the reference case. Furthermore, three wall directions, namely north, south and west, for the installation of PCM and eight different phase transition temperatures (Tm) are considered in order to evaluate the situation in different aspects. In the second part of the study, the cost-saving, payback period and reduction of carbon emissions by PCM utilization are discussed. The computed results revealed that the orientation of PCM close to the inner surface inside the wall saves 12.9% of energy during the heating period, while improper configuration slightly increases energy consumption. Besides, the PCM with Tm = 16 °C for the indoor temperature set to 18 °C results in the highest energy saving, while the PCM with Tm = 26 °C has the lowest payback period (1.8 year). Carbon emissions are reduced by 52.7 kg/m2 by using the most suitable PCM wall, throughout its lifetime.