In recent years, modular construction has made its way into the mainstream construction conversation, being used for everything from hotels to office buildings. And as the construction industry continues to face a workforce shortage, raising costs and other uncertainties, modular construction is being turned to as a way to improve safety, productivity, quality, cost, schedule and sustainability performance.
A look at the current and future prospects of modular building
Hyatt Place modular hotel, built by NRB Modular Solutions. Photo courtesy of the Modular Building Institute.
Increased Interest
There are two types of modular construction: permanent and relocatable. Permanent modular construction (PMC) is used for single- or multi-story whole building solutions that can be delivered in modular sections. The PMC modules can be integrated into site-built project or used as stand-alone solutions complete with MEP, fixtures and interior finishes. Relocatable modular construction (RB) is designed to be reused or repurposed multiple times and can be transported to different building sites. These types of buildings are most commonly used for schools, construction site offices, medical clinics, sales centers and other places where a temporary space is needed.
On the permanent side, John McMullen, marketing director at the Modular Building Institute (MBI), notes that affordable housing has seen a huge boom. He notes that the Canadian government recently announced that it is continuing its multibillion-dollar effort to build modular housing, while big cities around the United States are pushing their own similar initiatives. “On the relocatable side,” he says, “the demand for space remains steady, particularly for education and mobile office space.”
Overall, “The market for commercial modular construction has just about doubled in the past few years,” McMullen says. “Various drivers have caused the demand for different segments of the industry—multifamily housing, hospitality, health care—to fluctuate, but on the whole the entire industry has benefitted from greater awareness of the benefits of modular construction and greater capability as more factories open up.”
Even though wood-frame construction has been the most common type of modular construction, in recent years there’s been a shift toward more steel-framed modular construction, which can be used for taller buildings. “Both side of the industry are seeing an increased interest,” says McMullen.
“Wood and steel are used for different kinds of projects (low-rise versus high-rise, for example) and vary in use in different countries, but modular construction on the whole has increased. Again, this is due to larger industry bandwidth and more owner/developers realizing the benefits (shorter construction schedule, cost certainty, faster ROI, etc.) of modular construction.”
Blossom Street Stack in Houston, built by Boxprefab. Photo: Rame Hruska
A Design Evolution
Rame Hruska, AIA, LEED AP, co-founder of Houston-based Boxprefab, shares that after starting Intexture Architects with her husband Russell Hruska, doing purely design, they quickly saw the need to transform the practice to a design-build firm to ensure their designs were executed in the best possible way for their clients. “Working in modular construction is one more evolution to that process, and while there are technical complexities involved, it’s a construction method that can be applied in different ways from modules to components to suit the project needs,” she explains.
The Hruskas started Boxprefab because of the challenges they saw with typical site-built construction, especially the ability to ensure the building is built correctly, down to every detail such as window flashings and roof penetrations. “Even with a full-time superintendent on a job site, it’s just not possible to verify every detail in the field and if one thing is not done right and covered up by a subcontractor it can lead to huge issues down the road,” she says.
“Modular is our preferred method of construction because it allows us complete control of the construction process,” she adds. “Through our team members and quality control process, we can truly ensure that every aspect of the structure is built correctly and tested in advance—it’s simply just not possible to do that with conventional site-built construction.”
Interior of Blossom Street Stack in Houston, built by Boxprefab. Photo: Rame Hruska
A Controlled Environment
While the overall planning and design process for modular construction is similar to that of traditional construction, there are many reasons architects and contractors have taken an increased interest in modular. By building the modules in a controlled factory setting, there is less waste with fewer site disturbances to contend with. Construction can occur simultaneously as site work, allowing projects to be completed anywhere from 30 to 50% faster than traditional construction.
During the pandemic, many construction sites were required to limit the number of people on the job site. Having fewer people on-site at one time, as well as maintaining social distancing, made getting all of the trade work done in a timely manner more difficult. On the other hand, the controlled environment of modular construction allows work to continue around the clock.
According to Hruska, the biggest advantages to modular construction include the speed and reliability, quality, and sustainability. “Residential modular construction is typically half the timeframe of conventional site-built construction,” she says. “This is achieved because work in the factory is not subject to weather delays and can happen concurrent to site work and foundations, reducing variables and adding reliability to the construction process.”
In terms of quality, Hruska explains that they have a quality assurance team, enhanced processes and testing procedures that simply are not possible in site-built construction. “Additionally, we build with additional structural members, strapping and hardware to create an enhanced structure to withstand the rigors of transportation. Our structures meet the equivalent of hurricane-force winds traveling down the highway and the equivalent of an earthquake as they are lifted and set in place. We create stronger buildings and tighter, more energy-efficient envelopes than typical site-build construction through this process.”
“Because our structures are built in a controlled environment and materials don’t get wet during construction, they have tighter tolerances and are not subject to warping, shrinking, swelling, mold and mildew,” she adds. “Modular construction is inherently more sustainable with the ability to utilize material more efficiently with less waste and create less impact on site. The ability to produce buildings that are both good for people and the planet is really important to us.”
Harvest Marijuana Dispensary, built by Modlogiq Inc. First-place winner in the Permanent Modular Retail category of the Modular Building Institute’s 2021 Awards of Distinction. Photo courtesy of the Modular Building Institute.
Future Potential
The demand for modular construction has definitely been increasing. “After the pandemic became widespread here in the U.S., there was an immediate need for hospital rooms and urgent care facilities,” McMullen notes. “Once those immediate needs passed and we started to understand the longer-term effects of the pandemic, affordable and multifamily housing really took off. We’re proud of all our members for stepping up, and we’re proud that the groundwork we laid over the past years helped get a lot of these projects moving quickly.”
However, Hruska says a common misconception is that modular construction should be less expensive than site-built construction. “In fact,” she says, “modular construction is built to the same building codes and utilizes the building materials as site-built construction but has significant additional costs including enhanced structural members, additional transportation and setting costs, factory overhead, and full-time quality control processes. There are also efficiencies with the process, and for us right now these costs are balancing out so that we are in line with comparable high-quality, site-built construction in our region.”
When it comes to the future of modular construction, McMullen thinks the future is extremely bright. “With an increasing need for affordable housing, a renewed focus on hospitality and education as we hopefully near the hopeful of the pandemic, and a shrinking industry workforce, it’s only a matter of time before more and more projects go modular. The benefits are too good to ignore.”
And, according to Hruska, modular construction has enormous future potential to transform the construction industry. “Labor is becoming increasingly expensive and more difficult to obtain skilled workers especially for single-family residential construction,” she explains. “We see the ability to bring good design to scale while still allowing customization for clients’ needs and specific sites. In the future we are looking ahead at the ability to integrate additional technology and robotics into the construction process.”