Prefabrication/Modularization—It’s Not Just for MEP Anymore written by Tim Wies

Prefabrication and Modularization have been two of the hottest topics and catchphrases in the construction industry over the past couple of years. For several years now, the MEP trade contractors have been prefabricating and modularizing large amounts of their scope of work in their shops for just-in-time delivery to the job sites for final installation. It seems that many feel this is a newer concept, especially in relation to the Interior/Exterior Finish Systems Trade Contractors (fancy name for Drywall Contractors). Please humor me as I give a little history lesson and then set out a vision for the future.

Showing my age, when I got into the industry as a pup in the late ‘70s and early ‘80s, exterior wall prefabrication/panelization was the rage on construction sites. Some panels were load-bearing metal stud panels, some were bypass sheathed or unsheathed metal stud panels, and some were completely finished metal stud framed wall panels. While at Wies Drywall at that time, I was involved in the field with panelizing and installing the exposed aggregate cement board panels on the Westport Sheraton tower, the smooth cement/polymer board panels on the Craigshire office building in the Westport area, as well as numerous metal stud-only “ribbon panels” between ribbon windows in the two and three story office buildings in the Westport area. Other drywall companies in the St. Louis marketplace also were involved in panelization in some form at that time. From the mid to late ‘80s to the mid ‘90s panelization totally went out of vogue. What were the causes of the rapid rise and fall of panelization at that point? The rise can be attributed to the 15%-18% interest rates and hyperinflation in the late ‘70s and early ‘80s. Owners were open to any ideas on how to get their buildings built faster – enter prefabrication Version 1. Once interest rates went down and stabilized, the country was still in a recessionary period, so low price was king and panelizing contractors found out it was not cheaper to panelize, just quicker, so the industry reverted back to stick framing as it was more cost-effective and had little upfront detailed engineering required. Prefabrication Version 2 started around the mid to late ‘90s. Grau Contracting prefabricated numerous exterior and interior wall panels on a large project at Fort Leonard Wood, and followed it with finished exterior wall panels and prefabricated interior walls and soffits at the Mills Mall. Prefabrication became a hot topic; the cause was shortage of manpower at that time and hyper aggressive schedules. Once again prefabrication fell out of favor due to increased manpower availability and lack of cost-savings for contractors or owners. Fast-forward to today – what is driving the demand for prefabrication? What has changed since Prefab Versions 1 and 2? What have we learned? And will it become the norm this time?

What we have learned over the years is that not every project is right for panelization.

Today’s demand is due to numerous influences, first on most folks’ minds is the aging and shrinking construction workforce. This manpower issue is compounded by evermore complex construction projects with extremely aggressive schedules being supervised by a less experienced site management team. Complex projects require an extremely skilled workforce which we are fortunate to have here in St. Louis, but that is not the case in a large percentage of the country. Aggressive schedules take a toll on trade contractors in several ways. In a lot of instances, the trade contractor’s manpower graph looks more like an inverted backwards checkmark in lieu of the age-old standard bell curve. This high spike in manpower followed by a “drop-off-the-table” manpower situation at the end of the project, in conjunction with a shrinking workforce, creates scheduling nightmares for trade contractors, especially ones who are typically expected to push the project schedule. Aggressive schedules also require all trades to be working on all areas of the project, all of the time, and at the same time. This would be a challenge even for a grizzled veteran general superintendent to be the conductor of this orchestra – think about the “sound of the music from the orchestra” led by less seasoned superintendents. 

A lot has changed since Prefab Versions 1 and 2. On panels, we no longer weld our studs to the steel concrete pour stop, we must consider deflection and seismic loads and use slide and drift clips. We no longer use hand sketches for panel design – today’s technology allows for multiple detailed drawings for each panel to be used by in-house QA/QC supervisors. They make sure each stage of a panel’s life from framing, to sheathing, to air/moisture barrier, to finish skin, meet the standards required to ensure a quality end product. Another change over the years are the many options available for prefinished exterior wall panels. Sure, we still do finished panels utilizing EIFS, but we can provide many other cladding options as well. If your design calls for fiber cement siding – check; metal panel siding such as Dri-Design, with or without continuous insulation – check; thin brick veneers – check; rain-screen systems – check; standard backup panels, with or without membrane air barrier – check; punched window openings with aluminum frames and glazing – check.

What we have learned over the years is that not every project is right for panelization. Some projects might be better stick-built if they are smaller, they are already fully designed, and there is not enough time on the front-end to engineer, design, and fabricate the panels, or if other jobsite conditions do not favor prefabrication. We also know that prefabrication is not cheaper on its own. The true cost savings is due to shortened construction schedules allowing the owner to produce income sooner and the GC to decrease their on-site general conditions. We have learned over the years that in the traditional Design, Bid, Build project delivery method panelization provides no real tangible cost benefit to the owner/GC due to the intricacies of panel attachments and probable rework of parts of the structural design. To produce the greatest cost efficiency the panelizing contractor needs to be involved up front with the design and engineering team to provide guidance and solutions. This allows them to be fabricating the panels while the sitework, foundations, and steel structure are going up. Once the steel is completed panel installation can start immediately.

This time I do see panelization and prefabrication of load-bearing wall panels and prefinished exterior wall panels to have staying power. TJ Wies Contracting has been installing Eisen load-bearing wall and floor systems for over five years. Owner demand continues to be strong as owners see the value of cutting four to five months off an eighteen-month schedule solely through prefabricated load-bearing wall and floor systems. The same goes for prefinished exterior wall panels. There is true value to having a project not only “in the dry” but finished on the exterior two to three months early.

Tim Wies is President/CEO of TJ Wies Prefab, a division of TJ Wies Contracting, Inc. TJ Wies Prefab is a preferred installer of Eisen Load-Bearing Wall and Floor Systems, and is a Sto Panel Technology affiliated fabricator and installer of exterior prefinished and backup bypass wall panels. 

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