## 5 Conclusions  
During the buildings' design stage, weakening the impact of the mountain environment on the thermal performance of buildings is an effective strategy for achieving energy efficiency in cold regions with a mountainous climate. In this study, a numerical model was developed to evaluate the thermal performance of a gabion building envelope under three weather conditions, and it was compared to the traditional building envelope. The effect on the convective heat transfer coefficient (CHTC), the wind pressure and the air infiltration were investigated by using CFD and heat transfer simulations. Then, DesT simulations were conducted by using the CHTC results to comparatively illustrate the impact on room base temperature and building load. It is fair to say that the gabion can enhance a building's thermal performance in mountainous climate regions, resulting in the improvement of building energy efficiency and thermal comfort. The main conclusions can be drawn as follows:  
1. Regardless of the weather condition, gabion significantly reduces the CHTC on the exterior building surface by effectively reducing the wind speed on the external building surface, even that of a surface parallel to the incoming flow direction. These leads to a 69% decrease in the average CHTC value for the building under condition I, 67% under condition II, and 63% under condition III;
2. The gabion can obviously change the wind pressure distribution on the exterior building surface, reduce the maximum wind pressure difference on external surfaces of the building envelope, and effectively weaken the impact of air infiltration  
Figure 10: Impact of the gabion on maximum heat load and cumulative heat load for the heating season.  
on the building's energy consumption. Compared to a building without gabions, the air infiltration rate of a building with gabions is also greatly reduced under three conditions;
3. A gabion located on the outside of the exterior wall can improve the room base temperature throughout the heating season, and the average room base temperature is 2.02 \({}^{\circ}\)C higher than that of a building without gabions. Therefore, a gabion can have a significant impact on saving energy for building heating and enhancing the adaptability to the unfriendly external environment;
4. The gabion structure has a non-negligible influence on the heating load while lowering the maximum heat load (up to 10.7%) and the cumulative heat load (up to 24.8%) during the heating season.  
The thermal performance of gabion buildings in a mountainous climate is examined in this paper, and a feasible analysis model and research method are provided. In the future, the thermal performance of gabion buildings under other climatic conditions could be further analyzed. Additionally, it becomes necessary to further construct an experimental system and employ experimental methods for conducting related performance analysis.  
Conceptualization, F.L. and Q.Z.; methodology, Y.L.; software, W.G.; validation, F.L., Y.L. and Q.Z.; formal analysis, Y.W.; investigation, F.L.; resources, Q.Z.; data curation, Y.L.; writing--original draft preparation, F.L.; writing--review and editing, Y.L.; visualization, Y.W.; supervision, Q.Z.; project administration, Y.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The data presented in this study are shown in the paper.  
The authors declare no conflict of interest.