Key Considerations for Modular Construction

Modular construction has the potential to eliminate half of the time and virtually all of the stress associated with large-scale commercial construction projects. The technique requires a number of key decisions to yield the greatest success, however.

Here are four important considerations regarding modular construction:

1. Pre-Construction Design Process

Unlike stick-built construction, developers cannot change small project details throughout the construction phase. To realize the benefits of modularization, developers and designers must plan to use modular construction from the outset, and commit to a building design earlier in the process than in conventional construction.

Unfortunately, it is usually late in the game, oftentimes not until spending three to six months or longer designing traditional plans, when developers realize those plans are incompatible with modularization. That’s because the foundation and platform, or plinth, on which the modular units will be assembled needs to be designed to accept the structural point loads of the units. Therefore, designing footings and foundations before knowing the modular structural system to be used will likely render plans obsolete.

2. Structural System

Once an owner has decided to use modularization, the next step is to decide the material to be used for the structural system. Steel, concrete and wood are all common options, and the choice will impact the resilience of the structure, so it’s important to know the limitations of each.

Wood is the weakest of the three, susceptible to rot and pests, and flammable. Therefore, it is most commonly used for smaller structures of only a few stories, such as single-family homes.

Concrete is strong and noncombustible, but also very rigid, with a tendency to crack under stress more easily than other materials.

Steel is considered the best option for large-scale modular construction. It’s the strongest and least vulnerable to warping, pests and fire. Not all steel is the same, though.

There are two common options for modular steel structures: structural steel, also called “black iron,” or light-gauge stud framing, made of cold-rolled steel. A developer’s choice will likely depend on the height of the building they’re looking to erect. Light-gauge steel can only support buildings of up to eight stories, making it a good choice as a substitute for wood framing. Structural steel, on the other hand, is strong enough to support buildings towering 30 stories or more.

3. Modular Manufacturer

The next most important decision one needs to make early in the process is which modular manufacturer to select. Like everything else in life, not all modular manufacturers are the same. Today, there are less than 100 modular manufacturers in the United States, with roughly 90% building only with wood. These modular manufacturers focus primarily on the single-family modular home market, and sell to a network of dealers/contractors who transact with the public.

The other 10% are the modular manufacturers in the United States able to use steel. Of those, only a handful have the experience, capacity and capability of producing high-quality black iron-based structural steel for modular buildings. iBUILT is one of them.

An important question to ask when considering a potential manufacturer is: Can this modular manufacturer produce the structural framing system the developer/owner wishes to use for this building?

4. Type of Construction Contract

Finally, after selecting the modular manufacturer, one needs to consider how to manage the pre-construction and construction processes. This usually boils down to determining who will design the building, permit the building, construct the building, and what modes of contracts will be used.

Another consideration is whether they seek a single, turnkey approach to the building—where one company handles all aspects of construction, including both onsite and offsite work—or whether to use two separate teams.

Some owner/developers want a single source responsible for everything, from design through permitting, construction and completion. Others may have already brought on a contractor to handle the onsite work, and will seek a separate manufacturer to handle the modular units.