Unitized and Beyond: What’s Next for Unitized Glazing Products?

Unitization has helped make curtainwall installation cost-effective and efficient with better quality control compared to stick built installation. And unitized curtainwall is just the beginning. Some recent projects have involved installing the glazing into a precast wall panel, and then installing the entire panel on the jobsite. Where else could unitization take the industry?


Vicente Montes, façade engineering associate at Curtainwall Design Consulting (CDC) of Dallas, sees a trend toward more sophisticated unitized curtainwall on a case-by-case basis.

“We’ve done some projects where the team wanted a double-span curtainwall unit that covers two floors with one unit rather than one floor with one unit,” he says, pointing out that this method doesn’t necessarily save time or money. “It takes just as many people to install a double span as it does a single span. For a single span, you may need five people. For a double span, you’d need double the people so you’re not saving on the number of crew members. It also takes just as long to install because it’s not just one anchor on one floor but two anchors on two floors.”

Montes also explains that this type of panelization isn’t always possible because glazing contractors may not have access to the tower cranes needed to install them. The floor cranes many glazing contractors use have limits to their weight capacity.

When working on projects such as these, it’s important to establish who is responsible for the installation, as it can often involve several trades working together.

Schüco USA, based in Newington, Conn., currently has methodologies to build entire terraces to attach to a building onsite. It allows for all  waterproofing to be done in a cleanroom production environment, which means that sealants dry better and gives the fabricator more control over the units’ performance. Schüco USA president Attila Arian says parametric design using 3D modeling is making it much easier to build complicated structures using simple modules. These models bypass paper drawings, allowing the information from a 3D model to be input directly into production and fabrication machinery.

According to the Modular Building Institute, modular construction is a process in which a building is constructed off-site, under controlled plant conditions, using the same materials and designing to the same codes and standards as conventionally built facilities.

Arian says that the productivity of jobsites and construction has been declining in the U.S. over the past 50 years while the cost of operating a jobsite is going up.

“Anything we can move into the prefabrication methodology is going to improve efficiency, including glazing. Can the entire glazing package be prefabricated and modularized? I would say no. There’s always a certain portion of the podium and special entrances that will require field installation,” he says. “I do believe we will see an increase in prefabrication and assemblies in production lines as the ability to build taller buildings with that methodology increases.”


Michael Smalley, director of business development at IWR North America of St. Louis, says his company has worked on projects using panelization but not full modularization. However, he believes the industry may be closer to a modular reality than many think.

In a future where entire buildings are constructed modularly offsite, Smalley feels strongly that all of the same stakeholders and tradespeople should be involved as they would in more traditional construction methods.

“Just because it’s being taken offsite doesn’t mean we can skip steps in the process. The project needs to be designed well and tradespeople need to be involved in the coordination,” he says.

Some of the benefits of modularization could be a decrease in required labor and an increase in jobsite safety. Smalley hopes that in a controlled environment it could be possible to incorporate more recycling and material optimization than on traditional jobsites.

Currently, Smalley says it would be easiest to modularize projects such as hospitality applications and hospital towers where the rooms are all similar. He says the feasibility of including glass and glazing into the modules would depend upon the overall geometry of a building.

“I’m envisioning that punched windows would be the simplest starting point. Could we do the same with window wall and curtainwall? I do think we could get there eventually,” he says.

Arian agrees that low- to mid-rise buildings that are considered “fair and square” are more likely candidates for modularization. However, he believes that with the improvements in digital design, they could become less “cookie cutter like” and more appealing to architects.

“There are a number of companies that have the funds available to come into the industry and disrupt it. Companies such as Uber and Airbnb have disrupted traditional markets that never believed there was a way for a company to come and take over a big piece of the business,” he says. “It’s also going to happen to construction. Glazing contractors should be part of this and embrace it.”


To make modularization involving glazing a reality, many questions need to be answered. For Smalley, one of those concerns is addressing who would manage the construction. Would it be the general contractor or a third-party consulting firm?

Arian points out that big modular construction companies already exist and as more trades become involved, it could be set up like a shop model. He says that many glazing contractors are already familiar with offsite fabrication, so it wouldn’t be a major shift.

“The type of buildings that can now be built in a modular fashion is increasing constantly due to digital tools. Transportation for large units also is becoming more feasible and affordable,” he says.

Another issue Smalley says is that each trade would bring different quality control standards and protocols to the table. They would need to develop a holistic approach to construction and the details of how each system ties into the overall structure. Montes adds the key to making this work would be to figure out how to detail transitions and ensure the system is weather tight.

While small-scale modularization is already happening, it could be a while before more complex facades are included, if at all. If the industry does move further toward this direction, Smalley says it’s important for contract glaziers to be open minded.

Jordan Scott is an assistant editor for USGlass magazine. She can be reached at jscott@glass.com.

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