Due to recent advances in technology and consumer awareness, there is a growing acceptance of the environmental advantages of offsite, prefabricated, and modular building systems.
Think of modular construction as a construction process rather than a type or style of building. The difference between offsite and traditional, onsite construction comes from where the building is built, not how. Sixty to 90 percent of commercial buildings are built offsite in a factory-controlled environment and transported and assembled at the final building site.
Due to the quality-controlled process, modular construction by nature is material and resource-efficient and allows for the following green benefits:
1. Less construction waste
2. Design for deconstruction
3. Repurposing buildings for secondary locations
4. Fewer site disturbances
5. Improved indoor air quality
6. Reduced construction schedules
Less Construction Waste
Offsite construction makes it possible to optimize construction material purchases and usage while minimizing onsite waste. Since modular builders work in a factory controlled environment, they can have many construction projects underway simultaneously in one location, so they are better able to re-inventory materials that may have been allocated to one project, for use in another. With site built construction, a general contractor would send any overage to the recycle bin or to the dump.
Bulk material deliveries sent to the manufacturing facility are also stored in a protected environment safe from theft and exposure to the environmental conditions of a job site.
Design for Deconstruction
Modular buildings are also more readily designed for deconstruction. The fact that the modular building is assembled in modules means that it can be disassembled at the end of its useful life. Buildings can be reused by simply reversing the process in which they were installed on site.
One of the most sustainable concepts for the building industry is remodeling and reusing existing modular buildings instead of building new ones. Relocatable buildings have a useful life of approximately 20 years if properly maintained and permanent modular buildings can last over 60 years. Capital improvements can also extend the useful life of these buildings. Once the buildings have served their purpose in one location, they can be moved or reassembled to accommodate the next use.
Fewer Site Disturbances
Because of the unique offsite construction process, modular construction workers report to work at the same manufacturing facility rather than commuting to and from various construction sites. Once a project is completed in the factory, the building components are then transported to the site for installation. This process greatly minimizes the traffic from workers, equipment, and perhaps most importantly, suppliers. Rather than making multiple deliveries to the site, modular manufacturers buy in bulk with fewer deliveries.
Improved Indoor Air Quality
Many of the indoor air quality issues identified in new construction result from high moisture levels in the framing materials. Because the modular structure is substantially completed in a factory-controlled setting using dry materials, the potential for high levels of moisture being trapped in the new construction is eliminated.
Reduced Construction Schedule
With modular construction the site preparation and construction take place at the same time. This allows for most projects to be completed 30 percent to 50 percent sooner. This streamlined and efficient work process results in few labor hours needed per project, thus fewer trips to the site per project. Earlier occupancy of a building also allows for faster revenue generation.