Efficiency of Space Utilization in Supertall Towers with Free Forms

Amid rapid urban growth, migration from rural to urban areas, and economic expansion in many countries, supertall towers offer sustainable solutions to the rising demand for housing and commercial space. In contemporary skyscraper design, the adoption of freeform architectural configurations emerges as a highly favored approach, representing a notable trend in the field. The optimization of spatial utilization stands as a paramount criterion in the design process of freeform skyscrapers, bearing substantial significance for sustainability. However, the current literature lacks comprehensive research on space efficiency in supertall towers with free form, despite their widespread use. This study aims to bridge this significant gap by conducting a thorough analysis of data from 35 selected case studies. Two representative case studies are presented in the paper. The key findings of this chapter are as follows: (a) the average space efficiency was found to be below the threshold values of 75%; (b) all skyscrapers with free forms employed a central core typology, primarily catering to mixed-use functionalities; and (c) the outriggered frame system emerged as the predominant structural system, while composite material was the most utilized structural material in the examined cases. The author expects that these findings will provide valuable guidance, particularly for architectural designers, in their endeavors to promote the sustainable development of freeform skyscrapers. In this sense, the architect must take into consideration the structural logic in the design and circulation elements to improve space efficiency, with a special emphasis on the dimensions of the service core and structural elements, as they play a crucial role in achieving this goal.