FRIDAY, MARCH 10, 2023
A contractor is reportedly using a “top-down” construction method to build a 16-story-tall mixed-use building near downtown Detroit, with work expected to be finalized in June this year. According to reports, once completed, the building will be the first successful top-down project in North America.
“We’re taking a sequence of work that had traditionally been done in a serial manner and identifying where we could pull all of those activities in parallel,” Steve Houston, Senior Director of LIFTbuild, told The Architect's Newspaper.
“Unlike with conventional methods, in which the building footprint is consumed with the ground floor construction, the LIFTbuild system allows us to continually use this area, effectively creating ‘more space’ on our tight site.”
About the Project
Plans to move forward for the $64 million project were first announced by LIFTBuild in 2020, adding the first residential tower to Greektown’s skyline. Dubbed Exchange Detroit, the 207-foot-tall building is anticipated to feature 165 residential units.
In addition to condos and apartments, spaces offer 5,800 square feet of retail, hospitality and office space on the first floor.
LIFTBuild is serving as the general contractor for the project, as well as being a member of the development team. Dearborn-based Ghafari Associates and the architecture firm 1+1+ are working as part of the design team.
LIFTbuild was launched in 2017 to improve worker safety, construction timelines, and other longstanding issues commonplace to the American construction industry.https://t.co/XtRK3MW0Nw
— The Architect's Newspaper (@archpaper) March 6, 2023
The project broke ground in September 2021. At the end of April of last year, it began its first lift on the project and was locked into place on May 1. Work then began at grade on the 16th floor, which LIFTbuild attributes to an “effort to emulate an efficient, manufactured process, much like an automotive assembly plant.”
The novel, top-down approach reportedly allows workers to efficiently sequence work around the structural cores while coordinating with material suppliers to create unitized assemblies for everything from the building’s walls to its mechanical, electrical and plumbing (MEP) systems.
Additionally, the method allows workers to construct on the small triangular, three-quarter-acre site, as it is surrounded by city streets, businesses and Detroit’s elevated People Mover system. These obstacles reportedly prevented any potential tower crane usage.
Two concrete cores were first constructed to form the main structural element of the building, containing the stairs and elevators. Then, as each floor was completed, eight strand-jacks lift the floor into position over a period of seven hours. A video of this process can be viewed here.
The floor segments rise at a speed of about 20 feet to 30 feet per hour, connected to the strand jacks by a proprietary steel-frame rigging system built by Engineered Rigging that can be reused for subsequent floors, Engineering News-Record reports.
The assembly team also lifts the structure of each floorplate 6 to 8 feet to install MEP systems, akin to mechanics working on the underside of a car. A jacking system then lifts and locks each fully enclosed and weathertight floor into place.
According to reports, this process took between 9 and 10 days per floor. Painters and other workers were even able to continue on the interiors in a regulated setting during a snowstorm earlier this year.
Most of the building’s façade is reportedly clad in alternating vertical stripes of glass and metal paneling. Conventional methods would require the building envelope to be installed by workers on the outside, wearing safety harnesses and a crane bringing materials up to height.
“Here, it’s coming unitized and prefabricated in one already completed piece,” said LIFTbuild Chief Operating Officer Joe Benvenuto. “But it’s still a conventionally tested joint that has been engineered and somewhat modified to just accommodate our system and methodologies. We try to use the connections and other aspects of conventional construction that have been tested and relied on and not have a bunch of one-off systems.”
LIFTBuild reports that this process is 30% faster and 20% cheaper than a conventional build process, partly because only 50 workers are required on site. Additionally, worker safety is improved due to less fall hazards and “comfortable” working heights.
“We constantly communicate and talk to our subcontractors about why this is the right height for us for access, installing work, or for moving around the site,” said Benvenuto. “We can do that at any elevation. It’s all about the efficiency of the worker.”
According to recent reports, the top 14 stories are now in position, with only two ground floors left to be added using conventional construction methods. Work is anticipated to be completed by June.
Tagged categories: Building Envelope; Commercial Buildings; Condominiums/High-Rise Residential; Construction; Contractors; Design; Design build; General contractors; Good Technical Practice; Mixed-Use Facility; Ongoing projects; Program/Project Management; Projects - Commercial
