## 1 Introduction  
### Motivation  
In 2016, the total population of the world reached 7.44 billion, and it is still rising [1]. Architecture is undoubtedly a necessary condition for human existence, not only for residences, but for industry, agriculture, commence, and other activities (e.g., buildings are needed as carriers for production or as offices). In view of the rapid growth of the population, the construction industry must also develop at the same speed to address such growth. Currently, the energy consumed by the construction industry comprises the largest part of the world's energy consumption [2]. The energy consumption in commercial, residential, and public buildings accounts for 30-40% of the world's total energy consumption [3]. In developing countries, this situation is even more pronounced. According to data from the Building Energy Research Center of Tsinghua University, China in 2018, the total energy consumption used in the building industry in 2018 reached 1123 Mtce; this was divided into commercial and non-commercial consumption energy. In China, the amount of energy consumed by residences was 1032 Mtce (the equivalent of one million tons of coal,1 Mtce = 20-30 GJ), accounting for 20% of the country's total energy consumption. The total annual carbon dioxide emissions of the residences were approximately 2.2 billion tons. The energy consumption of residences in 2018 was almost double that of 2001, and the per capita energy consumption increased from 291 kgce/cap to 739 kgce/cap (\"Kgce\" is the energy of 1 kg of standard coal and \"cap\" is the energy consumption per capita) [4]. This phenomenon has aroused the attention of scholars, who have begun to try to use renewable energy such as solar energy, wind energy, biofuel, biomass energy, geothermal energy, and hydroelectric power generation to put forward various theories and approaches for residential energy conservation [5]. This is a good beginning. Although scholars and architects continue to work on improving residential energy efficiency, the results are often not as expected. [PERSON] [6] mentioned that it is unreasonable to implement a unified technology and energy consumption indicator system for low-energy buildings. The joint application of key technologies is an important strategy to achieve low energy consumption goals. It is predicted that by 2050, there will be twice as much energy consumption and building-related carbon emissions today than the current levels, or even more [7]. Most scholars and architects only focus on energy conservation issues in cities. They refer to successful cases of energy-saving in developed countries, and formulate a large number of similar building codes and laws to restrict the energy consumption of urban buildings. This approach has achieved certain results [8]. However, the effectiveness of saving energy depends on the national conditions. In China, 42.65% of people live in rural areas [9]. This energy consumption is also considerable, and thus, there is great energy-saving potential. China's urban residential buildings are mostly high-rise, centralized residential buildings. Once they are completed, it is difficult to carry out large-scale reconstruction. Therefore, the energy consumption issues are mainly considered before construction. In contrast, most rural residential buildings adopt an independent courtyard-style residence mode, and the connections between buildings are not close. Any small-scale renovation of any building will not have a significant impact on other surrounding buildings [10]. In addition, rural buildings are generally closer to nature, and can effectively use the surrounding natural environment for passive energy-saving designs. If the unique advantages of rural courtyard-style residential buildings can be efficiently used and concepts of passive design can be introduced into the designs of rural buildings, these will greatly reduce energy consumption, and effectively improve energy utilization.