Modular buildings, to paraphrase, “are not your grandfather’s mobile home.” Well, some are, in fact, mobile, but the majority of modular construction projects are permanent, fixed, and profitable buildings. Modular, as a construction concept, dates back more than 150 years—according to the Modular Building Institute, perhaps as far back as the 1600s.
The first wide use of true, modular construction in the U.S. can be dated to the 1800s, when the California Gold Rush generated an increased need for buildings to house the influx of prospectors. Prefabricated buildings, broken down into panels and shipped West by train—steam or wagon—were raised on individual claims and in collections to create towns filled with housing, saloons, and churches for miners and those who followed to provide services to them.
Since then, modular building construction has been used for a variety of purposes. An increased need for housing, changes in the labor force, and growing dissatisfaction with the current onsite methods of construction, have renewed interest in modular construction. The COVID-19 pandemic has created a need for additional hospital and emergency facilities in many countries and areas—famously, in Wuhan, China, two hospitals with 2,600 total beds, were raised using modular techniques and simple steel frames, in just 10 days.
In the United States, from 1947 to 2010, productivity in construction barely changed at all according to McKinsey & Co. Meanwhile, productivity increased by more than a factor of eight in manufacturing and by more than a factor of 16 in agriculture—both industries that have embraced automation. Ah, automation. Will robots replace carpenters?
There are three primary opportunities for automation in construction. The first is automation of what are considered traditional physical tasks on-site—for instance, robots laying bricks and machines paving roads. The second opportunity comes from the automation of modular construction—or rather production—in factories, including 3D printing of components such as facades. And the third centers on digitization and the subsequent automation of design, planning, and management procedures.
A substantial shift to modular construction off-site could have a significant impact on the construction workforce, but the transition will take decades. Producing individual components, or modules, in factories lends itself to much more machine use than what can be done on-site. A lot of the construction in these factories is still done manually, but over time, as scale increases, the process will become more automated. McKinsey estimates that about 15-20% of new building construction will be modular in the United States and Europe by 2030.
But not all benefits come from productivity gains. According to Markets & Markets, the growth in modular can also be attributed to increased concern toward work-zone safety, need for lower environmental impacts, and supportive government initiatives. Permanent modular buildings, by type, accounted for the largest marketshare in the modular construction market. As for modular building materials, steel is the fastest-growing segment in terms of value and volume. Steel frames are lighter in comparison to other wall materials, which allows building structures to be transported and craned into a place more efficiently, resulting in less disturbance to the local area and reducing cost. It is also recyclable, and hence, buildings made from steel can be easily dismantled. It is one of the most popular materials for use in relocatable buildings used as commercial buildings, warehouses, and retail outlets.
Residential accounted for the most significant demand for modular construction in 2019, in terms of value and volume. Modular construction can build residential building structures in about half the time as compared to conventional site-built construction methods.
Because the easiest tasks to automate are repetitive and physical activities in predictable environments, onsite construction is less likely to become fully automated. Construction environments are usually unpredictable: not only do people and equipment move around, each construction site and project is tailored to specific customer demands, architectural designs, and geographical and site requirements.
Automating more of the construction process could help deliver infrastructure and buildings faster, without needing to reduce headcount. This means there will be demand for construction work—and workers—for a long time to come. McKinsey expects the overall number of jobs in construction to grow rather than shrink, with up to 200 million additional jobs by 2030 if countries fill global infrastructure gaps and boost the affordable housing supply.
Redshift, a division of Autodesk, notes that a variety of technologies are used in manufactured buildings such as additive manufacturing, 3D printing, robotics (both on and off the jobsites), CNC-controlled machining, and laser scanning for field verification. Collaborative project-delivery models such as IPD (integrated project delivery)—which put information sharing at a premium—are moving toward more integration, too. Early signs suggest that robots might be as important to construction as people—eventually.
With many trade skills disappearing, and skilled workers harder and harder to come by, builders are looking for alternative methods to handwork and manual methods of assembly. With the combination of technology breakthroughs, economic shifts, fewer workers, and increased cost to skilled trades, the demand for prefab has never been higher—or more critical. Right now, buildings are still mostly built; in short order, claims Redshift, they are going to be assembled.
Again, take hospitals. In a time when the nation’s inventory of healthcare facilities is stretched to its limit by the COVID-19 crisis, Alabama-based BLOX is industrializing the task of hospital construction. With a flexible, integrated cycle of design, manufacture, and construct, BLOX’s approach to modular hospital construction serves as a model for adding capacity to a stressed healthcare system.
BLOX started out prefabricating smaller standard components such as ceiling racks, surgical racks, hospital headwalls with electrical and medical gas systems, and bathroom modules complete with plumbing. Today, it has taken the concept to what it calls “uber modules”—15-feet wide, 15-feet tall, and 60-feet long—that can comprise an entire trauma center, or a set of rooms such as labs, imaging rooms, patient rooms, and even break rooms.
The BLOX team uses a building delivery system called DMC (Design Manufacture Construct). With DMC, a building can consist of any combination of standard components, subassemblies, panels, modules, and uber modules. Components are designed and fabricated in the factory environment using repeatable processes and systems. The actual hospital construction site then becomes an assembly site.
The Modular Building Institute explains modular buildings are generally stronger than site-built construction because each module is engineered to independently withstand the rigors of transportation and craning onto foundations. Once together and sealed, the modules become one integrated wall, floor, and roof assembly. Building offsite ensures better construction quality management. Manufacturing plants have stringent QA/QC (quality assurance/quality control) programs with independent inspection and testing protocols that promote superior quality of construction every step of the way.
Beyond quality management and improved completion time, modular construction offers numerous other benefits to owners. Removing approximately 80% of the building construction activity from the site location significantly reduces site disruption, vehicular traffic, and improves overall safety and security. Additionally, the modular process allows contractors to do foundation work at the same time others are building walls and components. This concurrent construction gets a jump on the structure, with walls going up as the foundation cures.
With these schedule advantages, projects are completed 30-50% faster than traditional construction. And in the case of modular homes being constructed in California’s Napa Valley by Factory_OS, 1,300-sq.ft. structures are being assembled in a mere four hours—from foundation to turning the lights on.
Original Article: https://constructech.com/getting-in-a-modular-mood/
