The stepped-back profile of a 66-story skyscraper in Austin, which will be the state capital’s tallest building when completed this fall, is a consequence of the city's height and massing limits to keep the view corridor to the capitol's dome unblocked.
In place for decades, the legal restriction on the height and form of new buildings in certain viewing points of the state capitol is called the Capitol View Corridor. It mandates that a building not intersect with the view of its dome, says Steve Welton, the Sixth and Guadalupe project executive in JE Dunn Construction's Austin office.
Rising from almost a city block site at one of Austin’s busiest intersections, the 865 ft, 2.2-million-sq-ft Sixth and Guadalupe high-rise, designed by architect Gensler, has 19 levels containing 655,000 sq ft of office space, topped by 33 levels of with 630,000 ft of residential units. The tower sits on a 12-story retail and parking podium that fills the city-block site.
Michael L. Hildebrand, LEED AP, vice president of construction for one of the development's three co-developers, Lincoln Property Co., adds: “The parking deck covers the entire site up to the ‘floor’ of the capitol view corridor. He notes that the team used 3D modeling throughout to ensure the design restrictions were met.
The site is also on a prominent block in Austin’s Central Business District, surrounded by commercial and residential buildings, including a historic property which needed to be protected and could not be moved.
For laydown, the team is working around the activity and traffic in the area; scheduling deliveries to 30-second increments; replacing existing utilities; locating worker and material hoists; and coordinating crane placement in the right-of-way. The crane is the tallest in the contractor's history, at an initial freestanding height of 360 ft and a final height of 884 ft under hook.
Work on the tower began in late 2019. Soon, Covid-19 hit and complicated construction by shrinking the labor force. In addition, "demand for skilled trades is extremely high," due to the significant volume of work in metropolitan Austin, "but there is not enough depth of those resources locally,” says Welton.
The high-rise is the first project in Austin to do an exterior perimeter safety screen system, beginning at level 18, to provide maximum protection on the active upper levels of the structure.
“Our team is building three very different projects and components within one building,” says Chuck Lipscomb, senior vice president and Austin office leader for JE Dunn. “That requires the project team to think about the project separately and as one unit at the same time.”