This article originally appeared on the Builder website.
Recently, a combination of issues have bubbled to the surface of the building industry. A shortage of housing brought on by an increase in construction costs has driven the conversation of factory-built housing to the forefront. In the last three years, the building industry saw a 15% increase in construction costs nationally, and upwards of 30% within some larger urban cities. These increases are fueled by a shortage of workers and skilled trades that never bounced back after the recession. As builders look for more cost-effective solutions to meet the housing demand, factory-built technology is gaining national attention.
Start-up companies have promised to streamline the labor-intensive means and methods of construction with new factories that produce prefab panels, shipping containers and modular cartridge units among an array of other technologies. Factory-built is not a new idea and has been around for years, but its resurgence seems to be hitting the market at the right time under these special circumstances. This, accompanied by modern technology, could be a game changer as it develops shifting the building industry.
I spoke to Ryan Flautz, associate principal, at KTGY Architecture + Planning to explore how these new factory technologies will affect design.
What is the difference between prefab, panelized and modular factory-built construction?
Ryan: Every day we hear these terms tossed around as we discuss and consider our design solutions. Most often the terms are incorrectly used, so let’s clarify.
Prefab is the overall term for off-site factory-built construction. This includes panelized systems, pre-cut, shipping containers and modular units constructed in a controlled environment in what we typically refer to as factory-built.
In modular construction, a structure is assembled in cartridge units, typically six-sided boxes that are prefinished and structurally self-contained. These modular units are then shipped to the site and craned into place. Modular has maximum size constraints for shipping and is typically in a “box” form, which can limit design options.
In panelized construction, the walls of the structure are built in a factory, then shipped to the construction site and assembled. This expedites the construction framing time, is more accurate, and allows for greater design flexibility as there are no “box” requirements.
“All modular homes are prefab homes, but not all prefab homes are modular,” says Revolution Precrafted Properties.
What are the design considerations to go factory-built housing?
Ryan: Every project is different and each needs to be evaluated independently. As we evaluate the design, we can look at both options and what will fit best without jeopardizing the design integrity. For example, the design of the KB Home ProjeKt, using the Entekra panelized system, required spatial variety with large open spaces, transom windows and raised plate heights that would not fit well with the modular “box” limitations. Not to say that it could not be built as a modular “box” project, but the panelized system worked better with our design and removed limitations allowing for greater flexibility.
On larger apartment type projects, where stacking units of consistent sizes are repeated throughout the building, the modular “box” would be a great option and would decrease construction time and increase quality even further as most of the units are prefinished and little field work is required.
Historically, modular homes have been associated with lower quality, but this attitude is starting to wane. The flexibility and quality are much greater than in the past and, once you understand the limitations of modular and prefab, you can then challenge the design and create special environments for the end user.
What are benefits of using factory-built housing?
Ryan: Zero waste, reliable schedules, energy efficiency and higher quality are just a few of the advantages. All of these are great benefits to any project and are serious issues to consider, but the bottom line is time. Factory-built housing is faster to construct and assemble, thereby supplying the market with more affordable housing faster and meeting the demand at a lower cost. Furthermore, some states have code differences, which can also make modular construction less expensive to build.
How will the KB Home ProjeKt incorporate factory-built construction?
Ryan: In designing the KB Home ProjeKt, KTGY’s goal was to design a project that would be Net Zero Energy, sustainable, have great design and, most importantly, be cost-efficient, making the home affordable to the market. This was a tall order. To meet these goals, KB Home and KTGY teamed up with Entekra to discuss utilizing factory-built housing.
When looking at the list of goals and construction timeline, there was no question that a factory-built panelized system was going to be the catalyst to getting us past the goal line. Working closely with Entekra, we were able to utilize their knowledge of panelized systems in the early design stages. This enabled us to tie this technology into the design, maximizing efficiencies, while also allowing for design flexibility.
What is your outlook on modular and prefab being used more in the future?
Ryan: We are still in the early stages of developing a design process when working with factory-built housing. We understand there are great advantages, but there are also challenges that still need to be worked out. The home building industry has legacy processes that, when combined with factory-built housing, create limitations. The traditional production home building process of stick building a structure, attending a “frame walk” or “box walk” and modifying the design in the field during construction, contradicts the effectiveness gained using factory-built housing. Making changes to the prefab systems on the construction site can be extremely costly and difficult to do.
There needs to be more built-in flexibility with factory-built housing to allow for some modification in the field without difficulty, while also allowing more direct decision making earlier in the design process. The traditional process must change, and all the players must buy in on this new way of thinking for the future of factory-built housing to be widely used. However, the outlook is certainly promising, and the benefits should be strong enough reasons for the industry to make changes. The question remains: as economies change, will the advantages of factory-built housing hold?
To learn more about the design process with factory-built housing, be sure to stay tuned to www.builderonline.com/kbhomeprojekt.