Some Assembly Required: Building Skyscrapers With Modular Construction

SAR4Modular construction has been around for decades and used in a variety of applications such as single-family residences, data centers, schools and hospitals. A number of benefits of modular construction have been cited such as decreased costs, shortened project schedules, reduced waste and safer conditions. With the modules being constructed inside a factory it eliminates weather delays caused by rain and snow that normally affects buildings constructed using conventional methods. Because the modules are constructed in a controlled environment in an assembly-line method, material waste and man-hours can be greatly reduced. Modular construction also offers a safer approach since working at height is eliminated. This is not to say that modular construction won’t have its fair share of critics and controversy.

When modular goes wrong, it can go terribly, horribly wrong. The Pacific Park B2 project in New York was started back in 2013 and at that time was going to be the world’s tallest modular construction at 32 stories and 322 ft. The project was going to cost 15% less than a conventionally built project of the same size and be completed in just 18 months.

Early on, the B2 project was the subject of a lawsuit filed against the NYC Department of Buildings and its commissioner by a pair of trade organizations. The Mechanical Contractors Association of New York and the Plumbing Foundation City of New York accused the department of violating the city’s construction codes by not requiring licensed plumbing and fire suppression contractors do the work on the modules at the offsite construction facility, which they argued would compromise the safety of the project. The Department of Buildings fired back stating that since the units are being constructed offsite, the construction codes don’t apply and will be compliant as long as licensed professionals perform all the connections once the modules are erected and secured into place at the construction site.

That was just the beginning of the problems. About a year after the project began work was stopped near the end of August 2014, stalling the project out at 10 stories. On September 2, 2014 the developer Forest City Ratner and the contractor, Skanska USA filed lawsuits against each other, each blaming the other for cost overruns and delays in construction. Skanska claims the plans for the project were flawed leading to misalignment of the modular components. Forest City blamed Skanksa for poor execution and accused them of closing the factory where the modular units were being built to bilk more money out of the project.

The company building the modular units was a joint venture between Forest City and Skanska and was their first foray into this type of construction. Forest City has since bought Skanksa out of their portion of the business and is working to complete the project. Even when it does get completed, it won’t be competing for the title of world’s tallest modular anymore since taller modular projects have been completed since B2 began. Their approach involved building the modular shells at one site and then shipping them to another to be fitted out before being delivered to the construction site for placement

SAR3On the flipside, when modular is done correctly, it can be done cheaper, faster and safer than when employing conventional construction methods. Prime examples include the projects being completed by Broad Sustainable Buildings. The company has completed a 30 story hotel in 15 days and a 57 story building in 19 days earlier this year. BSB’s methods are a little different, their modular components are reminiscent of those old Erector sets you played with as a kid. Instead of manufacturing completed units, they cut and weld modules such as columns, crossbeams and floors. The floors are fitted out the floors with plumbing, electrical and HVAC ducts. All of the components including walls and doors are numbered, placed on top of the floor units they correspond with and shipped to the construction site where they are lifted into place and bolted and welded together.

The rate at which BSB’s structures are assembled is impressive and several time-lapse videos of projects being erected have gone viral. This is not to say that BSB hasn’t run into any issues. The 57 story project finished this year was on hold for a year after only a week of work had been completed. The building was in a heavily used flight path and negotiations resulted in the original 97 story building losing 40 floors in order for approval to resume construction. BSB’s plan to build the world’s tallest building was sidelined in 2013. That project, known as Sky City, looks to be getting back on track and may actually get built if construction permits can get approved.

It’s been proven that modular construction can deliver on its promise of faster, cheaper and safer.  Whether or not the use of modular construction for skyscrapers will ever match that of conventional building methods remains to be seen.

This article first appeared in the Fall 2015 “Skyscraper Issue” of our Construction Data Quarterly.

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