The Truth Behind Prefab Homes

The facts and fictions behind building a ready-made, prefab home.

Photo: FabCab / See more of this home here.

It seems like every day we’re introduced to a newer, smarter, more efficient and eco-friendly way to build a home. From the materials, to the positioning, to the structure’s shell, everyone seems to be touting a new way to build even better than before. But when it comes to considering building a prefab home, many of us feel like we’d be taking a step back in time instead of into the future — an opinion that many homebuilding experts are working hard to dismiss.

“People have these preconceived notions about what prefab homes look like, but, in truth, a prefab home is totally indistinguishable from a site-built house. It’s because of this that I’m still surprised when I run into someone who clings to the stereotype that these houses are all double-wides and ugly little boxes,” explains Sheri Koones, author of the new book PreFabulous + Almost Off the Grid. So, what exactly is prefab building? Short for prefabrication, prefab refers to a construction approach in which parts of the building are manufactured and assembled in a controlled environment (typically a factory) before they are transported to the building site.

The idea behind prefab construction is the logic of the assembly line — the assumption that mass-producing building components (think full walls and rooms) in a factory will save time, money and resources. And, as it turns out, most timber homes already fit into this category of prefab construction. Probably the most widely used type of prefabrication is panelized construction, a building method often used in timber framing. Most timber homes are at least partially built from factory-made components, namely structural insulated panels (SIPs) that are typically created from foam insulation sandwiched between two outer panels of plywood or strand board.

Transportable sections of these homes are built in factories and then shipped on trucks to the building site where they are assembled like large 3D puzzles.

Photo: FabCab

Why Build Prefab?

According to Koones, the benefits of prefab homes are as numerous as the ways to build them. Here are the most notable advantages of this building method.

Minimization of Waste

When you build a home on-site, you’re inevitably going to create a lot of wasted materials that end up in dumpsters and ultimately in landfills. In contrast, factories have the opportunity to recycle materials onsite and keep waste to an absolute minimum. “When you’re building a prefab home in a factory, all of the wood that isn’t used can be saved and used for another project. Any extra drywall can be sent back to the manufacturer to be recycled along with metal. Even the windows that are being delivered to your site also can be delivered for maybe five other houses at the same time, so there’s less fuel being used for delivery,” explains Koones.

Controlled Building Conditions

In a factory setting, homeowners can expect the expertise and experience in the construction of their home that comes with controlled factory conditions, experienced professionals and close supervision of each part of the house. To take the preciseness of prefab a step further, many of today’s factories use computer-controlled machinery to produce higher-quality houses at a lower cost. Plus, when you’re working in a controlled environment, your materials have limited exposure to the elements, meaning they have a much better chance of staying healthy and strong for longer.

Quick Delivery and Construction

In a society where we want things fast, prefab building also meets our need for quicker, high-quality construction. Unlike on-site construction, which typically requires sequential construction starting with the footing and foundation, all of the elements can be fabricated at the same time, which reduces the time spent in the factory and on the construction site. In addition, the popularity of structural insulated panels (SIPs) in prefab construction, speeds up the onsite construction time. A study conducted by RSMeans Business Solutions has found that SIP construction is dramatically faster than typical methods, stating that “a conventionally framed and insulated house of similar size and design would take approximately 122 percent longer to erect.”

Inherent Resilience and Strength

Because of the way that prefab homes are transported from one location to another, they must be stronger and more durable than traditional homes. Also, because the homes were built under ideal conditions, precise attention can be paid to the individual sections, and there are few places where the modular parts need to be fastened together on-site. All of these things create homes that will last longer and produce less waste and fill fewer landfills over time.

Photo: fotolia.com / JRP Studio

Prefab Homes: Fact vs. Fiction

There are countless reasons to build a prefab home, but there are still plenty of myths centered on this unique type of construction. Here, we separate the facts from fiction.

FICTION: Factory assembly means poorer quality.

Factory assembly is frequently misinterpreted to mean poorer quality (and, therefore, cheap) construction. “Not everybody realizes that modular construction is built to meet or exceed site-built construction — meaning we have to build to the same code that they build to onsite,” explains Greg Landess, vice president of sales and marketing for Campobello, South Carolina-based Blue Ridge Log Cabins. “In order to be a modular product, you have to design your homes to meet those codes. We exceed those codes because of how easy it is to do it here in our facility versus on-site.” “There is better quality construction in modular homes frequently,” concurs Jeff Whyte, architect for American Sail Cabin LLC near Chicago, noting the controlled environment, repetition and assembly accuracy as contributing factors. “Because [the module] needs to be fairly accurate once it shows up, the quality tends to be better,” he explains. Such accuracy also lends a degree of green building to modular construction, as very little material is wasted.

FACT: Modular-home construction is typically comparable in price to stick-built construction.

Another misconception many consumers have in looking at modular homes is that, because of the streamlined construction method, they are cutting costs. “Frequently, prefabricated and less traditional homes come up because people go into [a home-building project] and realize they don’t have enough money and start looking for other alternatives,” Whyte notes. But, he adds, “In this economy, people think they’re going to build for 50 cents on the dollar.” Although it may be more cost-effective for a developer building several modular homes, for individuals with a more personal, customized focus, there isn’t always such a significant cost differential between modular and site-built homes. “The two different lines aren’t articulated well in the marketplace so that consumers understand,” he explains.

FICTION: Modular homes all look the same: boring and unattractive.

Many people still interpret the building-blocks assembly of modular homes as limiting in terms of design availability. “I think that’s the biggest misconception — that you’re very limited with modular designs,” Landess states. “And you can see that because there are modular designs that are 200 square feet and there are modular designs for a home that’s 8,000 square feet.” Modules can not only be arranged in a variety of ways, but can be stacked on top of one another to create multiple-storied homes, with an exterior aesthetic comparable to any site-built home available.