# Space Efficiency of Tall Buildings in Singapore
## 3 Research Method
NFA is determined by subtracting the space occupied by the building's core (including stairwells, elevators, and mechanical systems) and other structural components from the total GFA. A higher NFA-to-GFA ratio indicates that a greater percentage of the building's overall area is being used efficiently for functional purposes, maximizing the building's utility. This is particularly important in high-rise developments where every square meter counts in terms of both functionality and economic return. The ability to achieve a high NFA-to-GFA ratio is crucial for developers and investors seeking to optimize the building's financial performance while delivering functional spaces for tenants. The core-to-GFA ratio, on the other hand, provides insights into how much of the building's total space is occupied by essential infrastructure--such as elevator shafts, staircases, and mechanical systems. This ratio helps determine how much of the building's area is consumed by non-usable spaces. A lower core-to-GFA ratio is generally preferable, as it signifies that a smaller portion of the building's total area is devoted to non-revenue  
Figure 2: Classifications by (**a**) core design; (**b**) form; and (**c**) structural system (by authors). generating elements, leaving more room for practical and rentable spaces. However, achieving an optimal core-to-GFA ratio also involves maintaining a balance between functionality and safety, as certain core elements like stairwells and mechanical shafts are essential for fire safety, accessibility, and building maintenance. Thus, while a lower core-to-GFA ratio can improve overall space efficiency, it must be achieved without compromising on the building's core functions. Both the NFA-to-GFA ratio and the core-to-GFA ratio are essential tools for understanding and optimizing space efficiency in high-rise buildings. Together, they provide a detailed perspective on how floor space is distributed between functional areas and essential services. By analyzing these ratios, architects and engineers can develop designs that maximize usable space without sacrificing structural integrity or building performance. For example, strategic core planning can significantly reduce the footprint of non-functional spaces, while advanced structural materials and systems can allow for slimmer load-bearing elements, further enhancing space efficiency. This holistic approach to space efficiency is not just about maximizing usable floor area--it also aligns with broader goals of sustainable urban development. Efficient space utilization minimizes the environmental footprint of a building by reducing the need for excessive construction materials and energy consumption. At the same time, it enhances the building's financial viability by increasing the amount of rentable or functional space, thereby generating higher returns for developers and investors. In cities where space is at a premium, such as Singapore, efficient space utilization is a critical factor in urban planning and development, contributing to the creation of sustainable, economically viable high-rise environments. By applying these insights, architects and developers can design high-rise buildings that meet practical, aesthetic, and financial goals while also addressing the environmental challenges of modern urbanization. Maximizing space efficiency not only ensures that buildings are functional and profitable but also supports the long-term sustainability of urban landscapes. In this way, optimizing space utilization plays a vital role in shaping the future of high-rise construction and sustainable urban development.