Choosing between prefabrication vs. on-site fabrication isn’t always easy. However, it becomes more straightforward when people take the time to weigh the specifics associated with their project and its resources. Here are some considerations to help. 

Supply Chain Availability 

Proceeding with on-site fabrication typically requires contractors to source materials or find partners who can. That’s not always the case with prefabrication. Prefab components often come from massive, highly specialized factories. The long-term and bulk agreements made between suppliers and representatives from those businesses may protect them from some supply chain shortfalls. 

A recent feature from the Sheet Metal and Air Conditioning Contractors' National Association (SMACNA) detailed the industry difficulties surrounding sourcing materials during the COVID-19 pandemic. Will Goff is the director of steel and commodities at Conklin Metal Industries. In September 2021, he said lead times were as long as 13 weeks, more than double the normal time frame. 

A related issue comes from the steel mills’ allocation policies that limit how much customers can purchase from them. Most won’t offer availability beyond their contractual minimums. Don Modesitt, the steel products manager at Hercules Industries Inc., also weighed in for the SMACNA piece.

“Domestic spot buys right now are completely up to the mills in terms of discretion, and most of them are not giving anything to anyone that has not bought from them in the past,” he says. 

These examples highlight why prefabrication could remove many supply chain struggles. That’s particularly true if the chosen providers have materials ready to use. 


Eco-friendliness is more frequently on people’s minds, and some contractors may think about sustainability as they ponder prefabrication vs. on-site fabrication options. Fortunately, certain materials are excellent choices in this regard. 

For example, aluminum provides infinite recyclability because people can melt it down for reuse without compromising quality. Some providers even ensure their aluminum primarily contains recycled materials. However, sustainability discussions should also include mentions of project-related transportation. On-site fabrication eliminates or greatly reduces the distance pieces must travel before use. 

Prefabrication can reduce production waste, however. ACP Sheet Metal makes prefabricated pieces by using modeling software. Nathan Dills, the company’s owner, says, “We’re experiencing greater output with less input and optimal material utilization. With this approach, we have increased shop productivity and cut material waste by approximately 60%-70% and can fabricate less expensively, faster and safer — all while reducing material waste.”

Progress with curbing waste can happen through methods other than prefabrication, however. 3D printing is one possibility. It’s already proving an option that makes home construction more affordable and efficient while producing less waste.

However, someone also used a desktop 3D printer to make molds for forming sheet metal. Each only costs about $5 in materials, making it a cost-effective choice. Many 3D printing construction projects use recycled materials, aligning with the sustainability aim.

Labor Requirements

Another challenge is that both the contracting and manufacturing sectors face labor shortages. One study revealed that 54% of civil contractors had difficulty keeping projects on schedule due to scheduling requirements. Additionally, in the fourth quarter of 2021, 64% of contractors said the skill levels of available workers didn’t meet projects’ needs. 

People thinking about prefabrication vs. on-site fabrication should assess how easily they could recruit the necessary local assistance for on-site work. If that seems like a far-fetched prospect, prefabrication could be more feasible. Manufacturing has struggled with labor shortages, too. However, some off-site fabrication facilities are well-equipped to meet customers’ needs. 

Rob Cross is the operations manager at Baker Group Advanced Manufacturing. He clarified how growth necessitated a recent expansion, saying, “We’ve done prefabrication work since the 1960s. We added a large shop in 1998, and since then, we’ve steadily gained momentum. Our growth necessitated this new expansion last year.” He was referring to a 144,000-square-foot facility that could have as many as 75 craftspersons working per shift. 

Tom Wengert, the vice president of the company’s sheet metal business unit, says, “The dynamic of the entire construction industry today is built on quality and speed. With this facility, we can prefab systems in a controlled environment, which improves quality while reducing labor costs.” He also noted that prefabrication reduced project site rubbish and construction congestion. 

Prefabrication vs. on-Site Fabrication Does Not Mean One or the Other

When some people weigh the differences in prefabrication vs. on-site fabrication, they conclude that they must only choose one of these options for each project. However, that’s an unnecessarily prohibitive assumption. 

The better approach is to assess whether certain project needs or phases are best suited for one or the other. Speaking to the client to get their preferences is another good solution. Explaining the pros and cons of each method can help them weigh in with informed perspectives. 

In any case, it’s important to consider that a project can certainly include on-site and prefabrication. Taking the time to gauge the best times to use each method is essential for overall success.