Modular construction has been around for decades but continues to evolve, with the latest forms falling into three categories: full stack, off the shelf and options from design-development firms. Hassell senior researcher Daniel Davis explores this world of modular, which is attracting major investment as the method gains favor during the coronavirus pandemic.
Modular architecture is having a resurgence. Although some architects have long espoused the benefits of building in a factory instead of on-site—less waste, no weather delays, more consistency—this delivery method has remained an outlier in terms of construction techniques. But change is coming. Fueled by a favorable economic environment, new technological developments, and the COVID-19 pandemic, modular architecture is showing up in new and unexpected ways.
The Only Thing New About Prefabrication Is the Recent Interest
Assembling architecture in a factory isn’t a new idea. In 1943, Skidmore, Owings & Merrill managed to construct 3,000 prefabricated houses for members of the Manhattan Project in the secret location now known as Oak Ridge, Tenn. By splitting construction among factories, field shops, and the job sites, SOM was able to assemble 30 to 40 houses a day from asbestos-cement panels that slid into preassembled frames.
Had the project been completed today, investors would have been salivating over SOM’s innovative application of industrial processes to homebuilding. Instead, the war ended, the federal housing contracts receded, and SOM went on to apply its systematic design approach to sleek skyscrapers. As for the Oak Ridge development, it was largely forgotten, one item in a long list of breakthroughs and sacrifices brought about by the war effort.
Some of the techniques employed at Oak Ridge aren’t too different from how houses are constructed today. Windows and casework are often manufactured off-site and then installed on site. In fact, whole assemblies such as machine rooms and HVAC systems are commonly built off-site and craned into place. Terms like “prefabrication” and “modular” are therefore a little murky since contemporary buildings always involve off-site manufacturing to some degree.
A modular building is a prefabricated building that consists of repeated sections called modules.
Modularity involves constructing sections away from the building site, then delivering them to the intended site. Installation of the prefabricated sections is completed on site. Prefabricated sections are sometimes placed using a crane. The modules can be placed side-by-side, end-to-end, or stacked, allowing for a variety of configurations and styles.
After placement, the modules are joined together using inter-module connections, also known as inter-connections. The inter-connections tie the individual modules together to form the overall building structure.