4 min read

Site Fabrication vs Prefabrication: Evaluating the Right Mix for Your Building Project

Written by: Thomas McCarthy

08.11.20

While use of prefabrication in construction dates back centuries, recently, the method is gaining significant traction in the industry. Various market segments are reporting an increase in prefabricated components, mainly due to their positive impact on cost, communication, and schedules. They also have various potential uses, the most common of which include:

• Exterior wall assemblies (glazing systems and skin systems)
• Structural steel
• Mechanical, electrical, and plumbing service racks and rooms
• Bathroom units and healthcare patient room service walls

A panelized wall system was used at the Microtel project in South Hill, VA.

The prefabricated construction market is projected to grow at a compound annual rate of 6.9%, reaching $153 billion by 2023. Several key trends are influencing this growth, including the use of Building Information Modeling (BIM), lean construction methods, and an emphasis on sustainable and resilient building practices. The use of BIM and lean construction methods result in a fully vetted and meticulously planned design that is much less likely to change once construction begins, reducing potential cost and schedule impacts. Fewer change orders also result in a significant reduction in construction waste.

This model depicts a large mechanical room that supports a mission critical operations and data center. With BIM and 3D modeling, each piece of equipment and the associated piping and valves was modeled. Piping was prefabricated off-site and installed using heavy equipment riggers.

Project teams share a common goal of reducing the time, materials, and labor required for a project. When controlling those three factors, the project experiences a reduction in overall cost. The benefits of prefabricated construction result in a level of productivity that may be unseen with traditional building methods. Research conducted by McGraw-Hill Construction reported several key benefits of prefabricated construction:

• Sustainable focus and waste reduction: Improved accuracy in the design stages results in the elimination of unnecessary material waste. Seventy-seven percent of industry professionals saw a decrease in waste on projects using prefab.
• Accelerated project schedule: Shorter installation duration result in a compressed schedule, quicker occupancy, and revenue generation. Sixty-six percent of industry professionals saw a decrease in the overall project schedule.
• Cost certainty: Minimizing rework and change orders, economies of scale result in overall project cost savings. Sixty-five percent of industry professionals saw a decrease in budget.
• Enhanced quality: Controlled environments result in a greater focus on details and minimized weather impacts. Seventy percent of industry professionals saw quality improvements.
• Safer work environments: Controlled factory-like, assembly line work environments result in cleaner, more organized workspaces and fewer hazards. Over one-third of industry professionals (34%) who are currently using prefabrication have seen site safety improve as a result.

VCU Health’s Adult Outpatient Pavilion in downtown Richmond features a variety of exterior wall systems. A glass curtain wall system that encompasses the bulk of the façade and cold formed metal panels where designed early in the coordination process to incorporate modular installation. The modular, unitized panels were prefabricated, dramatically reducing installation time. Panels were installed using a robotic arm, reducing manual material handling and overall risk exposure.

While incorporating just a small amount of prefabrication into a project produces noticeable benefits, it’s not necessarily the best option for every project. Project teams may choose to incorporate varying amounts of prefabrication based on several factors:

• Project delivery method: Prefabrication is particularly popular for design-build projects. Early collaboration between architects and designers/builders results in fewer change orders, and because prefabrication relies on solid design plans, this makes it an easy pairing.
• Schedule requirements: Depending on how tight the project’s timeline is, teams may choose to incorporate more prefabrication to ensure they meet the schedule demand. Using prefabrication minimizes on-site fabrication time.
• Weather and environment: Various weather or environmental conditions may make it difficult for teams to build safely on-site. This is an opportunity to implement prefabrication to ensure the safety of the project team along with a focused schedule management approach.

The construction industry is seeing a huge increase in the amount of prefabrication used on projects. Thanks to technological advancements, the prefabricated components used today are more reliable than those used for the last several centuries. With benefits such as reduced schedules, materials, labor, waste, and overall cost, many project teams are incorporating prefabricated elements into their project.

Previous Post Next Post