By Liza Moriconi
Modular construction is a methodology where buildings are constructed off-site as separate modules and later transported and assembled to create a completed structure. This construction method provides a quick solution to uniform and repetitive projects, such as multi-story apartments, hotels, hospitals, and business buildings. The modules are constructed under controlled conditions and designed to the same codes and standards as an on-site constructed building. The same materials are used in constructing the factory-made modules, such as wood, concrete, and steel, as would be used in conventionally constructed buildings. Typically, the modules are constructed to include the fixtures and interior finishes before they are transported and assembled. Once the module units are constructed, they are almost indistinguishable from site-built construction. According to Daniel McLennon, a partner in the San Francisco office of Smith, Currie & Hancock, nation-wide construction lawyers, there are many advantages to modular construction, but many of the challenges come from the legalities and responsibilities associated with contracts.
These disassembled buildings have been a construction solution dating back to the 1600s and were made more popular as the United States expanded west. Many preassembled homes were built in factories and shipped across the country to combat the housing crisis. With the development of the assembly line in 1913, the manufacturing of modular homes became easier and more accessible to consumers. As technology and design became more innovative, the modular construction industry began to shift from constructing homes to constructing more intricate structures, such as schools, hospitals, and office spaces. Today, with the assistance of new technology and resources, modular construction provides an attractive alternative to building customizable structures in a timely and convenient manner.
One of the most attractive aspects of modular construction is the amount of time it can save to complete the entire project. Because the construction of the modules typically occurs simultaneously as the on-site work, projects can be completed in a fraction of the time as compared to traditional construction. In traditional construction, foundation and on-site work must be completed before the construction of the building. The modular methodology allows for these to be worked on at the same time, just in different locations.
Safer construction is an additional advantage of using this construction method. With the help of highly automated robotic assembly lines, up to 60-90 percent of construction can be completed inside a factory. This indoor environment reduces the risk of accidents for skilled workers as compared to traditional construction. Workers are provided with more comfortable working conditions, allowing for higher productivity, more customization for the project, and production of a higher quality building. Since manufacturers can locate their plants where labor is more readily available for constructing modules, the struggle to find and keep laborers located near the project site is reduced significantly, according to McLennon. Factory produced units can also reduce waste in the overall construction process by allowing for more precise sizing and cutting of materials and the use of excess supplies.
Modular construction does, however, come with its challenges and disadvantages. As of now, modular construction is best suited for projects that are standardized and repetitive. These modules are mass produced, so the more uniform the building, the faster and easier the construction process will be. This creates a disadvantage for projects that are unique and require individualized modules to be constructed. More time and money must be spent on constructing these types of module units, making it almost unnecessary to use this method instead of traditional construction. This is why modular construction is typically limited to stackable, undeviating buildings that can be mass produced.
Transporting the module units can also cause problems when constructing off-site. After the modules are completed in an off-site location, they must be transported to be assembled and set in place at the desired location. Many times, the sizes of the individual units is limited by the allowable size on the road and even the capacity of the crane that will be used. Because of this, the project is often strictly limited in size, leaving little room for larger unique units. Moving the units from one location to another can sometimes be tricky. A common legal issue, according to McLennon, that is encountered is deciding who “bears the risk of loss” if a unit is damaged during transportation. Any damage that occurs during the transport could have serious consequences in the installation process. Modules that need to be repaired or replaced can impact the sequence of assembly, costing more time and money.
Modular construction is expected to have major growth as the time and cost savings may provide a significant advantage for the construction industry. This alternative provides a hopeful solution for housing and labor shortages across the country. “Construction can be done where there is labor,” instead of searching for laborers, and more housing options can be built faster to accommodate housing shortages, according to McLennon. There are many advantages that point to a bright future for modular construction, and with the help of advancing technology, this methodology can provide a practical solution for the construction industry.
Liza Moriconi is an intern for Civil + Structural Engineer Media, as well as a senior Civil Engineering student at the University of Arkansas. She can be reached at firstname.lastname@example.org.