Is Modular Construction Right for You? Weighing the Pros and Cons

We’re seeing an increased interest in modular home construction in Los Angeles following the recent Palisades and Eaton Fires. While this may be suitable for some residents, we hope this article can help homeowners decide for themselves whether it is appropriate for their circumstances or not.  First, we must understand the differences between the terms. Many use the terms “Prefabricated” and “Modular” interchangeably, but an important distinction needs to be made.

Prefabricated (prefab.) is an umbrella term, referring to any part of the construction process that is handled off-site, from a roof truss to a stair assembly. Wall panels could be prefabricated, for example, flat-packed onto a flatbed truck, and delivered to the jobsite for assembly. Many steel components are prefabricated as they allow welding to take place indoors, in a controlled environment.

Modular construction is a type of prefabricated construction, in which entire building modules (a kitchen/living unit or the entire home) are manufactured off-site in a warehouse and delivered to the jobsite where they are assembled into a complete building or are delivered fully finished and simply bolted to the foundation. You can think of modular construction as entire buildings or rooms being delivered to the jobsite on a truck. These buildings are typically finished with interior and exterior cladding already installed to reduce work on the jobsite. These homes are built to meet the California Residential Code and are treated as real estate, subject to local property taxes like site-built homes.

Manufactured homes (referred to as “mobile homes” if built prior to 1976) are built to federal HUD code, often built on a steel chassis so they can be moved and can be taxed as personal property if they are built on temporary piers or real property if they are permanently attached to the foundation.

Now that we have a better understanding of what Modular Construction is (and is not), let’s weigh the pros and cons.

Modular Home Benefits:

• Expedited Build Time – Since modular building components are built off-site in a factory, construction timelines can be accelerated as site prep and foundations can commence while the home is being built in the factory.

• Economies of Scale – Since these home builders build repetitively in bulk, there are potential cost savings in purchasing large quantities of building materials across many homes. This can lead to pass-through savings for the homeowner.

• Cost Predictability – The builder has more certainty over construction costs as the home was designed by the builder and there will be fewer surprises when construction starts.

• High Quality – Factories typically have tighter quality control protocols than on-site construction as construction occurs in a clean environment.

• Reduced Waste – Materials are ordered precisely, minimizing off-cuts and waste.

• Weather Independence – Since construction occurs indoors, inclement weather events (rain, snow or other events) don’t affect the progression of the project. 

Modular Home Drawbacks:

• Limited Design Flexibility – Custom designs, based on the needs of the residents are limited to the suite of standard modules offered by the company. Deviation from these standard plans can bring the project over-budget.

• Transportation Constraints – Modules are limited in size to 14’ wide when designated as an Oversize Load (with permits). 

• Site Limitations – Sites in remote areas, with difficult access, or with steep terrain can make craning and rigging impossible or at least cost-prohibitive.

• Resale Market Perception – Although quality has improved, some buyers still perceive modular homes as “less valuable” than site-built homes.

• Limited Customizability – Changes to the design at all phases can be difficult to incorporate due to the rigidity of the increased design parameters.

• Customer vs Client – In this scenario, the homeowner is considered a customer, rather than a client receiving tailored services.

• Up-front Payment – Manufacturers typically require significant deposit payments before construction. With the volatility of the industry, this means sometimes homeowners are left with no recourse if the builder goes out of business.

• Supply Chain Vulnerability- Often modular home builders will build their modular homes overseas in China and abroad where labor is cheap but will ship them to the US. This “offshoring” makes them susceptible to tariffs and trade policy fluctuations and may negate the original goal of increasing quality.

Our Approach: “Partial Prefab.”

At Form Found Design, our strategy is client-driven. For many of our clients, our response is to offer a hybrid solution that sees the time and labor savings of prefabricated construction and the site-specific advantages of a tailored design. We like to propose “partial prefab.” in which components can be manufactured off-site into walls, trusses, and other structural elements, then shipped to the site for assembly. With each of these partial prefab. options, the owner sees savings in terms of time on the jobsite (as much of the construction occurs in a factory setting with higher tolerances) as well as reduced waste (as parts are made to order).

One of these partial prefab. systems is a kit-of-parts process we like to call “Computational Framing”.  We’re able to design a custom home, then let the software generate a digital framing model that can be sent to a machine that prints each structural member to its exact length. Every wall and truss is comprised of steel studs that are printed to size based on pre-engineered specifications. A roll-former machine starts with a coil of steel, then with assembly-line precision punches, swages, and labels every structural member, resulting in a set of studs that are screwed together in the factory to form a wall or truss. These walls and trusses are then flat packed onto a truck and delivered to the jobsite where they are assembled and bolted together in just a few days. This system avoids the traditional pitfalls of wood-framing including the waste of off-cuts that are associated with wood-framed construction. Typical wood-frame construction generates from 10-30% construction waste, while computational framing sees 0% steel framing wasted as each member is printed to order. Steel framing is also termite and insect-proof as it is inorganic. Steel is also non-combustible, which equates to less fuel in the event of a fire. The high-precision of computational framing also eliminates the need for additional adjustments and modifications including backing for towel racks, etc. that would normally drag out the wood framing phase. This precision also allows other building components to be ordered faster with more certainty. Computational Framing takes all the benefits of prefabrication (speed, ease of assembly, higher tolerance, reduced waste) and combines them with the ability to create a fully tailored design based on the client’s needs.

Another partial prefab. system we’ve employed in the past is a system we call “Panelized Prefab”. This system arose from the desire to design large openings that necessitated steel beams and columns. The typical approach would have involved hiring a structural engineer to design a custom steel frame, but this approach is typically cost-prohibitive. We pursued over 50 pre-engineered steel building companies until we found one that would work with our design intent. These are often used for industrial buildings that require large open spans. The result was the Cleft House, which reduced the total cost of construction by 1/3 while achieving all of the ambitious design moves we sought. Not only was the steel frame prefabricated, but the exterior walls were also prefab. insulated metal panels with a Kynar finish. The result was a tailored design for a modular price.

While every project may be different, our values remain unchanged. Good design and the articulation of that design in service to our client’s needs is foundational to everything we do. If you have questions about your project, we’d be happy to meet with you and help you evaluate your options. Whether you're just beginning to explore possibilities o

r already have a clear direction, we're here to listen, guide, and bring your vision to life with purpose and precision. Let’s start the conversation.