## 5 Conclusions  
This study examines 14 cases of townhouses in Kaohsiung City, completed in 2022, with 15 different floor plans as research samples, totaling 237 unit plans. The research investigates the spatial configuration types of townhouses. The conclusions of the study are as follows:  
1. For townhouses, the architectural planning of each unit shows an 81.8% probability that the width, depth, and total floor area will fall within the following ranges: the width between 4.1 and 6.38 m, depth between 7.67 and 12.68 m, and total floor area between 136.02 and 192.39 m\({}^{2}\).
2. The width of the building exhibits a low negative correlation with the total floor area; that is, while a larger width tends to be associated with a smaller total floor area, the correlation is not pronounced. In contrast, the depth of the building shows a high positive correlation with the total floor area, meaning that a greater depth is strongly associated with a larger total floor area. Additionally, the width and depth of the building are moderately negatively correlated, indicating that a larger width tends to be associated with a shorter depth.
3. The primary internal space allocations within a building are as follows: habitable room areas account for 78%, stairs constitute 13.1%, and bathrooms represent 8.7%. Both the total area of habitable room spaces and bathrooms increase with the expansion of the total floor area, while the total area of stairs remains constant.
4. The most frequently planned stair location is the rear-right (RB) position, followed by the middle-right (RM) position, with the least frequent being the rear-left (LB) position. The average area and proportion of each stair type, ordered from smallest to largest, are as follows: I-shaped stairs, L-shaped stairs, U-shaped stairs, and C-shaped stairs. The frequency of planning each stair type, from highest to lowest, is as follows: U-shaped stairs, I-shaped stairs, L-shaped stairs, and C-shaped stairs.
5. In the research cases, the highest proportion of staircases across various floors are planned for the rear-right (RB) position, followed by staircases on the middle-right (RM) position in the second and third floors. This trend is primarily due to theprevalence of middle units in townhouses, with fewer units at the head, tail, and corners. Middle units are characterized by partition walls on the left and right sides, with natural lighting limited to the front and rear faces. By positioning the staircase in the central section, windows can be placed in the front and rear sections to provide lighting, optimizing the space for bedrooms and fulfilling the spatial needs of townhouses.  
Conceptualization, C.-C.T. and L.-S.H.; methodology, C.-C.T.; software, C.-C.T.; validation, C.-C.T., L.-S.H. and C.-F.H.; formal analysis, C.-C.T.; investigation, C.-C.T.; resources, C.-C.T.; data curation, C.-C.T.; writing--original draft preparation, C.-C.T.; writing--review and editing, C.-C.T.; visualization, C.-C.T.; supervision, L.-S.H.; project administration, C.-C.T.; funding acquisition, L.-S.H. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors declare no conflict of interest.