The Independent: A Case Study on Delivering the Architect’s Vision with an Economical Concrete High-Rise

The Independent—the latest high-rise in Austin, Texas—is the tallest concrete residential high-rise west of the Mississippi. LAM+DCI was the engineer of record for the 63-story high-rise totaling 89,930.5 m² (968,000-gsf); 360 residential units; and 728 parking stalls. This paper covers the design challenges required to develop a simple and cost-efficient structural system for The Independent; to accommodate wind loads based on the building’s shape and orientation; and to maintain the leading edge architectural design of the building with an economical solution. These results were achieved through coordinating the construction sequencing, including contractor means and methods; a basic grid of concrete corner columns and mega columns supporting post-tension slab and tension rods supporting extended cantilevers; a lateral design with a thin concrete building core, an outrigger system, and tuned liquid sloshing damper tank.