Sustainability is one of the most important design issues today, especially for tall buildings, the construction of which requires an abundant amount of resources. Selecting and designing a particular structural system for a tall building does an important role in determining its sustainability in terms of structural material usage. The braced tube, developed in the late twentieth century for tall buildings, is a very efficient structural system because it carries lateral loads primarily by axial actions of the perimeter columns and bracings, and still prevalently used for contemporary tall buildings. This paper studies various geometric configurations of the braced tube to determine more efficient ones which use less amount of structural material to meet design requirements and consequently save our limited resources. Braced tubes of different perimeter column spacings, bracing shapes and bracing densities are studied comparatively. Based on the study results, more sustainable geometric configurations of the braced tube are presented.