This month, the biggest event in residential construction takes place in Las Vegas, Nevada. The National Association of Home Builders (NAHB) and the National Kitchen & Bath Association (NKBA) will deliver Design and Construction Week 2025, the 12th anniversary of this partnership.
The NAHB part of the event is the International Builders’ Show (IBS). In the parking lot across from the North Hall of the Las Vegas Convention Center, you will find the IBS Show Village where, in addition to trade booths and displays, you will likely find dozens of houses, ADUs, tiny homes, etc. It’s a great display of the latest in living space options.
And therein lies the issue, what are the living space options? The homes on display aren’t all built to the the codes most show attendees normally work with — the ICC-International Residential Code (IRC) or the ICC-International Building Code (IBC). Instead, some are likely built to the HUD code.
To grasp the difference, you need to understand that the term “modular home” is a misnomer. Modular is a construction technique. Like modular furniture, modular electronics, or modular techniques used by the aeronautics industry for plane manufacturing, it’s a way to divide something into pieces that are individually built and then assembled into the finished product.
In the case of a modular home, modules built offsite must conform to the same codes that regulate site-built structures, which are based on the IBC or IRC.
The HUD code is different. Its official name is the Federal Manufactured Home Construction and Safety Standards, and it was created by the Department of Housing and Urban Development (HUD) in 1976. Homes built to this standard are called “manufactured homes.” The term is often conflated with “modular home,” which creates confusion even among some within the industry.
HUD developed the code so that manufactured homes could be built more affordably. In many cases, a manufactured home can cost 50% less than one built to the IBC or IRC. And the manufactured home industry is fantastic at building beautiful homes with attention-getting designs.
But does a manufactured home have the same value as one built to the IBC or IRC using modular construction? The answer is likely no. But how can you tell the difference? What changes were made to make it more affordable? If the professionals can’t tell, or don’t know the difference, how can we expect the homebuying consumer to know?
And we still haven’t talked about terms like ANSI A119 Park Models, NFPA 1192 Recreational Vehicles, CrossMod®, Tiny Home, or ADU. What code are these homes built to? When you attempt to deliver more affordable living spaces, compromises must be made to save costs. And remember that the homebuyer pays the final cost, not the first cost. Not doing something at the factory may mean that more costs will be incurred on-site. Cost transference isn’t cost savings!
Do the homework. Learn about the different building codes. Discover how costs are lowered and how efficiencies are gained with each. And then study the zoning rules. When a home is built to a specific building code, that may limit the locations where it can be placed or how it can be used. Do your part to learn exactly what the different building codes are and what they mean. Eliminating code confusion starts with you.
When you walk through the homes on display in the IBS Outdoor Exhibits, be prepared to ask what code the home is built to and understand what the answer truly means. If it’s not IRC or IBC, then ask what that means for the buyer. That is how we solve the issue of code confusion.
If you liked this article, you can follow Ken Semler on LinkedIn, where he offers daily insights and commentary about offsite construction.
