We have written recently about how the general construction industry is pushing for, and has moved towards a greater degree of integration with prefabrication and modular construction. Further evidence of this is contained in a new report from the McGraw-Hill construction group titled Prefabrication and Modularization: Increasing Productivity in the Construction Industry. The theme of the report is focused on the “trend to and re-emergence of prefab and modular“ through the use of BIM and green building, but the report also goes into another area of particular interest to the modular building industry, Lean Construction.
The lean construction concept was developed in the early 1990’s from the seminal work of Finnish professor Lauri Koskela, whose efforts focused on the inadequacies of the time-cost-quality tradeoff in construction management. Derived as a way to “design production systems to minimize waste of materials, time, and effort in order to generate the maximum possible amount of value,” lean construction is at the forefront of the latest tools and techniques employed by contractors for reducing and eliminating waste while recognizing significant savings in both schedules and budgets. This is especially true for companies in the modular building industry. The off-site construction and prefabrication of the building structure using an assembly line approach in a controlled factory environment not only saves significant time, but allows for a more structured use and recycling of construction materials compared to traditional site construction methods. As well as the improvement of overall product quality, the reduction of material scrap is best achieved in a production environment through the use of framing jigs for walls and roofs and the off-line assembly of plumbing, electrical, and HVAC systems. Modular manufacturing plants also utilize paint booths to minimize the release of harmful chemicals into the atmosphere while aiding in the overall speed of the production process.
The addition of prefabrication and modular building components in the lean construction mix has forced conventional construction firms to rethink how they manage tolerances to minimize waste when integrating these elements into their projects. The McGraw-Hill report includes an interview with Gregory Howell, cofounder and managing director of the Lean Construction Institute who emphasizes this point when he says, “When you’re doing stick built, everyone can adjust things in the field. When you do prefab and modular the game is different.”
