# Space Efficiency of Tall Buildings in Singapore
## 3 Research Method
Key considerations include function, the layout of the core, shape, the choice of structural systems, and the selection of materials. These elements are crucial in developing a design that not only satisfies aesthetic and functional requirements but also complies with rigorous standards for the structural integrity and safety of high-rise buildings in the varied and complex urban environment of Singapore. Core planning by [87] was adopted due to their thorough and detailed framework, which organizes the core design into four primary categories, as depicted in Figure 2a. Additionally, Figure 2b categorizes various building forms, with further details provided in Appendix B. This comprehensive model offers a systematic approach to core design, ensuring the seamless integration of multiple architectural elements. The diverse classification of forms enables a broad spectrum of design possibilities, allowing architects to create innovative and visually appealing configurations that also uphold functional and structural integrity. In the context of architectural design, choosing the right structural framework is crucial for optimizing space utilization in high-rise buildings, as it directly impacts the layout, dimensions, and effectiveness of the structural components. This study utilizes the detailed classification by [88], which categorizes tall building structures into various systems, including shear frames, mega cores and columns, outrigger frames, tube systems, and buttressed cores (Figure 2c). This comprehensive categorization ensures a systematic approach to selecting structural systems that enhance both the functionality and spatial efficiency of high-rise towers. Choosing the right materials is essential in determining the size and arrangement of structural components, which has a substantial impact on spatial efficiency. These materials are generally categorized as steel, concrete, and composite. This study focuses especially on vertical load-bearing elements, such as columns, which are fundamental to the structural integrity of tall buildings. The term \"composite\" specifically describes structures where the load-bearing elements are made from a mixture of concrete and steel or incorporate both materials to optimize performance and strength. Space efficiency in high-rise buildings refers to the strategic utilization of NFA in relation to GFA, with the primary goal of maximizing functional utility and economic value. In dense urban environments like Singapore, where available land is limited and construction costs are high, efficient space utilization becomes a critical factor in determining the financial viability and sustainability of tall buildings. By carefully optimizing the distribution of space, developers and architects can create buildings that not only meet functional needs but also generate higher returns on investment. This concept is shaped by a variety of structural and architectural considerations, such as core design, service area allocation, and the choice of materials and systems, which together dictate how space is allocated and used within the building. In this study, space efficiency is assessed by applying internationally recognized standards like BOMA (Building Owners and Managers Association) [89], RICS (Royal Institution of Chartered Surveyors) [90], and IPMS (International Property Measurement Standards) [91] in conjunction with findings from similar studies [92]. Two key metrics are used to quantify space efficiency: the NFA-to-GFA ratio and the core-to-GFA ratio. These ratios offer a comprehensive view of how well space is utilized, distinguishing between usable areas and the space occupied by essential services and structural elements. The NFA-to-GFA ratio is a critical measure of how effectively the available floor space is employed for practical purposes. It reflects the proportion of the total GFA that is designated as NFA--essentially, the area that is actively used for revenue-generating or functional activities.