# Performance-Based Evaluation of Courtyard Design in China's Cold-Winter Hot-Summer Climate Regions
## 4 Discussion  
In the development and evolution of traditional courtyards in the southern Jiangsu Province, a series of relatively mature and simple ecological strategies that suit regional features have emerged. However, there are still many issues that arise when bringing this traditional courtyard design element into modern architectural design. These issues include insufficient mastery of the spatial layout of traditional courtyards and ignorance concerning reasonable applications of ecological buffer spaces. This study focused on suitable strategies to affect and improve courtyard thermal environments. The Expert Building area of Jiangnan Furniture Museum serves as a case study to qualitatively analyze traditional ecological techniques. The environmental simulation software, PHOENICS, and the energy simulation software, DesignBuilder, were used to conduct quantitative analysis. From the analysis of the wind environment simulation results, the initial design, and the improved design, in winter and summer, several suggestions arise for the design phase:  
1. Adjust the spatial layout of courtyards to maximize natural ventilation for free cooling in summer and to prevent/minimize cold wind in winter. Courtyard buildings can be oriented with an opening toward the southeast to guide summer wind-pressure-driven ventilation and with closure towards the northwest to avoid cold currents in winter;
2. adjust the aspect ratio of the courtyard based on the impact of the depth and height-width ratio of the front and rear courtyard on natural ventilation. The aspect ratio of the courtyard can be determined based on other functions. When combining the front and rear courtyard, it is  
Figure 14: The energy use for thermal loads in rooms 1, 2, and 3 in winter under the initial design and improved design. recommended to moderately broaden the depth of the front courtyard and reduce the depth of the rear patio to promote wind-pressure-driven ventilation. Also, it is advised to moderately increase the height of the rear patio to promote the combined ventilation driven by both the wind pressure and thermal pressure. A further suggestion is to moderately increase the height of the enclosing wall on the northern side to form a rear patio to resist the cold northwestern wind in winter; and
3. build the ecological buffer space to consider its micro-climate regulating function and the impact of the opening and closing form of the ecological buffer space on energy use. Adjusting the ecological buffer space of the courtyard should also meet other functions. Boundaries between the usable indoor rooms and the corridor can be determined to separate the balcony from other buffer spaces. It is recommended to install operable and closeable glass on their lateral side to keep them opened in summer so that the buffer spaces are open wide for sunshade and cooling, while keeping them closed in winter so that the buffer spaces are closed tightly to preserve heat and save energy. Although three design parameters were evaluated with simulation models in this study, the study has some limitations. Firstly, the case study focuses on the integrative courtyard type in the southern Jiangsu Province, while extending results of this study to other courtyard types or other climate regions should take into consideration local culture, climate, courtyard form, etc. Secondly, this study is a preliminary phase of the mono-climatic regional analysis. The study of the ecological strategy of the quadrangle type in northern China, the patio type in southern China, and other types of courtyards which suit different regions need to be studied further. The discussion of the ecological strategy of courtyards focuses on building a suitable residential thermal environment. The impact of the ecological strategy of courtyards on other aspects (e.g., cultural impact) was not discussed in this study.