Framework for Balancing Structural Efficiency and Operational Energy in Tall Buildings

Abstract

Buildings are responsible for a third of worldwide energy demand as well as anthropogenic greenhouse gas emissions. Therefore, a holistic approach for energy-efficient design over the life cycle of buildings is necessary. In this work, the relationships between structural efficiency, energetic performance, and aesthetic design are explored in the context of tall buildings. The goal is to reduce the structural mass in order to reduce embodied energy while considering operational energy as well as the aesthetic expression of the structure. For this, we propose a framework that integrates code-based structural design of tall buildings with energy demand simulations, and perform a multiobjective optimization for a tall building in various climate zones. We show that structure can act as shading, that is, cooling savings are achieved with respect to a fully glazed building. Further, we illustrate the trade-offs between buildings with reduced mass, with comparatively little cooling savings, and heavier buildings, with increased cooling savings potential, for example, up to 50%. Finally, we discuss the impact of the column design in different climate zones. The resulting trade-offs allow the architect to make an informed decision between structural design and energy efficiency of the building without sacrificing the architectural intent.