Passive House-compliant, Prefabricated Panelized Construction

Challenge:  Within very limited construction time constraints and the need to keep the building occupied during construction, re-skin a 318,000 SF arts education high-rise building on a tight urban site while dramatically reducing the operational and embodied energy load for the building.

The exterior envelope of the existing building has fallen into an irreparable state, requiring wholesale replacement. Simultaneously, the entire HVAC system needs replacement. The objective is to design a high-performance building skin that would reduce the overall HVAC load. Doing so results in the downsizing of the mechanical equipment, which saves valuable space, first costs, and operational energy use over the life of the building.

Solution:  Utilize prefabricated, Passive House-compliant exterior wall panels (such as Megapanels^tm) to re-skin the entire building. These standardized panels – with spans of up to 40’ in length – include the 6” exterior stud framing, sheathing, triple-glazed large-format windows (U-0.12), insulation (R-30), and a geometrically modulated metal panel skin. While the original curtain wall envelope was mechanically fastened to the slab edge of each floor, the Megapanels instead span from column-to-column. This eliminates the need to reinforce the slab to accommodate the weightier panels, and because only one crane-lift can enclose a 40-foot length of building envelope, this system dramatically reduces time required to enclose the building compared with conventional curtain wall replacement.

Benefits:  On a tight urban site bounded by a major thoroughfare and adjacent campus buildings, scaffolding the building to replace the exterior skin is not a viable option. Only craning the exterior envelope into place is practical. Furthermore, because road closures are time-constrained, minimizing crane time is paramount. Large-format, prefabricated panels’ sheer size naturally reduces the number of lifts and time required to enclose the building.

This quick installation naturally reduces the amount of time that the essential teaching spaces need to be temporarily unoccupied – a fundamental disruption-reducing benefit that saves money and swing-space coordination. Built in a clean, temperature- and humidity-controlled factory setting, the assembly line fabricated panels typically provide a higher level of fit, finish, and performance than on-site construction can offer.