Ask anyone in offsite and modular construction what slows them down and the building code will come up. It is fair to be frustrated. It is also worth understanding why the system works the way it does, because the people who run it are not the obstacle. Most of them want the same thing we do: buildings that are safe, durable and affordable.
How the building code changes
The model codes most of the country uses are updated on a three year cycle. In year one, proposals for one group of codes go through committee hearings. In year two, the second group goes through the same process. In year three, there is a public comment hearing on everything, followed by an online vote of governmental members, who are mostly building code officials. The vote that will shape the 2027 editions took place this past May.
Then the real clock starts. Each state, and often each local jurisdiction, decides when to adopt a new edition and how to amend it. It is common to work in neighboring jurisdictions that are on different editions of the same code.
Is that slow? Yes. Is it slow by accident? No. Codes are life safety documents written largely from lessons learned the hard way. Consensus takes time, and confidence matters more than speed.
Building codes and modular construction
Much of the system assumes inspection happens on site, with walls open. In a factory, walls get closed up long before a local inspector would ever see them. States handle that through modular programs and third party in plant inspection, but the rules vary from state to state, which makes it hard to build one product for many markets. It is one of the five reasons I gave in February for why offsite adoption is slow.
There is real progress. In 2021, two consensus standards for off site construction were published: ICC 1200, covering planning, design, fabrication, transportation and assembly, and ICC 1205, covering inspection and regulatory compliance. They give jurisdictions a common framework. Like the codes themselves, they only help once they are adopted and used.
For context, factory built homes under the federal manufactured housing program have had a single national standard since June 15, 1976, one HUD describes as the only national building code in the United States. Modular buildings do not have that. They follow the same state and local codes as site built construction.
The cost of a slow approval system is not abstract. Federal Reserve researchers found that construction productivity declined most in places where permitting takes longer.
How offsite builders can help the code keep up
Show up. Participate in the code process and comment on proposals. Bring data from our plants and projects, not opinions. It's not secret sauce. Invite code officials and plan reviewers into the factory so they can see what in-plant quality control looks like. Hopefully it's not still a paper traveler. It's almost 2027. And design to the code that exists today, completely and clearly, so the first impression a reviewer has of offsite is a well-coordinated plan set.
Is the code holding offsite back? Partly. Are we holding ourselves back by not engaging? More than we would like to admit.
Code change is a long fight, and it rewards the people who keep showing up. As Rocky Balboa put it, "It ain't about how hard you hit. It's about how hard you can get hit and keep moving forward."
The code changes at the speed of evidence. If we want it to move faster, we have to bring more of it.