Understanding Prefabricated Building Enclosure Systems

Why: The decision to utilize prefabricated wall systems is one that must be made early in the design process and is based on a wide range of factors, including the complexity and size of a project, the amount of repetition or typical modules, the project sched­ule and the capabilities and experience of the project team. This approach requires "buy-in" from all parties, and recognition that early planning and coordination are critical. Just as well-planned prefabricated systems have the potential for both time and cost savings, poorly planned systems can result in delays, added costs and performance problems over time. Designers need to be aware of the benefits and limitations of these systems in order to deliver successful projects.

How: This article outlines basic considerations for choosing a prefabricated wall system including: sealant application, flashing, thermal performance, jointing strategy, and typical failure modes.

What: Buildings with significant exterior surface area and large amounts of material repetition are excellent candidates for unitized curtain wall, while buildings with less repetition, more unique wall conditions/geometries and smaller surface areas are less-suited for unitization and often use field-fabricated or "stick-built" construction methods. Unitized construction is not limited to glass-and-aluminum curtain walls, however. Many manufacturers offer prefabricated wall systems for more traditional cladding, such as brick veneer and metal panels-usually with windows and other fenestration already integrated into the assembly. Both unitized curtain wall and prefabricated wall panels provide an opportunity to maintain a heightened level of precision with respect to tolerance and workmanship through factory-controlled processes and methods, as well as quality assurance and quality control protocols. This article outlines the pluses and minuses of using prefabricated building enclosure systems.