Prefabrication, Preassembly & Modular Construction

The benefits are clear consider Prefabrication, Preassembly & Modular Construction for your next development project.

Construction workers typically are exposed to high levels of noise, dust and airborne particles, adverse weather conditions, and other factors that can cause fatigue and injuries and thereby reduce efficiency and productivity. New types of equipment can make an activity physically easier to perform, easier to control, more precise, and safer for construction workers. Similarly, changes in materials can reduce the weight of construction components, which in turn can make them easier to handle, move, and install. Manufacturing building components off–site provides for more controlled conditions and allows for improved quality and precision in the fabrication of the component.

Prefabrication, preassembly, modularization, and off-site fabrication involve the assembly or fabrication of building systems and/or components at off–site locations and plants. Once completed, the systems or components are shipped to a construction job site for installation at the appropriate time. One study that examined the relationship between changes in material technology and construction productivity based on 100 construction–related tasks found the following:

  • Labor productivity for the same activity increased by 30 percent where lighter materials were used;
  • Labor productivity also improved when construction activities were performed using materials that were easier to install or were pre–fabricated (Goodrum et al., 2009)

Prefabrication and related techniques allow for the following:

  • More controlled conditions for weather, quality control, improved supervision of labor, easier access to tools, and fewer material deliveries (Construction Industry Institute, 2002).
  • Fewer job-site environmental impacts because of reductions in material waste, air and water pollution, dust and noise, and overall energy costs, although prefabrication and related technologies may also entail higher transportation costs and energy costs at off–site locations
  • Compressed project schedules that result from changing the sequencing of work fl ow (e.g., allowing for the assembly of components off-site while foundations are being poured on–site; allowing for the assembly of components off-site while permits are being processed);
  • Fewer conflicts in work crew scheduling and better sequencing of crafts persons;
  • Reduced requirements for on-site materials storage, and fewer losses or misplacements of materials; and
  • Increased workers safety through reduced exposures to inclement weather, temperature extremes, and ongoing or hazardous operations; better working conditions (e.g., components traditionally constructed on-site at heights or in confined spaces can be fabricated off-site and then hoisted into place using cranes) (Construction Users Roundtable, 2007).

Prefabrication and related techniques are commonly used in the construction of industrial projects, but they are also used, if less frequently, for commercial and infrastructure projects. The committee believes that greater use and deployment of these techniques (if used appropriately) can result in lower project costs, shorter schedules, improved quality, more efficient use of labor and materials, and improved worker safety.

Read the full report from the National Research Council here:

modular house construction