# Space Efficiency of Tall Buildings in Singapore
## 3 Research Method  
A case study approach is administered to thoroughly collect and analyze data on 40 significant high-rise buildings in Singapore (Figure 1). This research method is widely recognized for its ability to capture a rich blend of qualitative and quantitative data, making it particularly effective for in-depth studies that require a nuanced understanding of complex subjects [76; 77; 78; 79; 80]. This case study method allows for a detailed exploration of the architectural and structural characteristics of these high-rise projects, providing insightsthat might be overlooked in broader surveys or purely quantitative analyses. By focusing on specific examples, this approach facilitates a granular analysis of real-world applications, highlighting both the unique and common features of each project. This level of detail helps to uncover subtle design elements and structural decisions that contribute to the overall spatial efficiency and functionality of these towers. According to the Council on Tall Buildings and Urban Habitat (CTBUH), a \"tall building\" has at least 14 stories or reaches a height of 50 m [81]. This paper adopts this standard to ensure consistency with established industry benchmarks in its analysis and discussion. CTBUH, a nonprofit organization, is dedicated to advancing global urban development by promoting sustainable and resilient cities, particularly in response to the challenges posed by rapid urbanization and climate change. As a respected authority in the domain of skyscrapers, CTBUH not only establishes criteria for classifying building heights but also bestows prominent titles such as \"World's Tallest Building\". The careful selection of 63 cases for this study ensures that the findings are both robust and broadly representative, particularly given the relatively limited number of modern high-rise buildings in Singapore. This substantial sample size enables the identification of key patterns in spatial utilization and design attributes. An array of the surveyed towers, which vary in height, and architectural style, greatly enhances the applicability and relevance of the research outcomes as shown in Appendix A. By incorporating such a diverse selection of cases, including a detailed comparison with international examples, this research provides a comprehensive and nuanced view of up-to-date practices and trends in high-rise building projects in Singapore. The selection of the 63 towers for this study was guided by a careful consideration of several factors to ensure that the sample is both representative of Singapore's modern high-rise architecture and diverse enough to capture key trends in spatial efficiency. The buildings chosen reflect a broad range of functional uses, including residential, office, hotel, and mixed-use developments. This variety is essential to ensure the findings can be generalized across different types of high-rise buildings in Singapore, which face unique spatial and functional challenges. As shown in Appendix A, the sample encompasses buildings of varying heights, ranging from mid-rise towers to some of Singapore's tallest buildings, such as the Guoco Tower (284 m, 65 stories) and Capital Tower (255 m, 52 stories). By incorporating buildings of different heights, the study captures a wide spectrum of space utilization strategies, which vary according to the scale and purpose of the building. The diversity in architectural style and structural systems--prismatic, free-form, and peripheral core designs--further  
Figure 1: Research method chart (by authors). enhances the study's ability to generalize the results. This approach ensures that the analysis is not biased toward any particular design or structural system, as evidenced by the wide array of structural materials and systems used in the selected buildings, including concrete, steel, and composite structures.