Faade Retrofit Puts An Efficient New Face on Old Buildings
Schüco’s ERC 50 Modernization Façade is a modular retrofit system that improves the looks and thermal performance of a building with minimal occupant disruption.
By Brent Ehrlich
What do we do with the large number of aging commercial buildings that have been built over the last half-century? These buildings often look dated, and they can be extremely inefficient; occupant comfort can be a problem, as can operating costs; and all these factors make it difficult to keep tenants. Demolishing these buildings is a waste (see “”), but bringing them up to date comes at a significant cost to owners and disruption to tenants. The ERC 50 Modernization Façade from Schüco, may help change this. This façade is a modular rainscreen system that incorporates windows and can be installed quickly without significantly disturbing occupants, while potentially delivering high levels of thermal insulation.
Installed on the building exterior
The ERC 50 Modernization Façade includes an aluminum load-bearing framework that is secured to the building structure using specially designed brackets. Installed on the building exterior at the ceiling level on each floor, these brackets can be adjusted in any direction to account for walls that are uneven or no longer plumb. The aluminum grid/frame is anchored to the brackets, and Schüco’s windows are installed and sealed against the building (the original windows are left intact until the entire exterior façade is finished). Mineral wool insulation is then secured to the building, and the thin panels are mechanically attached to the frame using EPDM gaskets—and without the use of caulk, making it possible for the panels to be easily replaced if damaged. After the façade is in place, the original windows are removed, and the interior is trimmed out.
This system can be configured to provide different thermal performance levels and looks depending on budget and need, but it was designed to integrate several Schüco products, including the company’s FW 50 series facades, AWS windows, and even its ProSol TF thin-film solar panels (although most any thin panel can be incorporated).
The FW 50 façade is available in an HI (“high insulation”) version, for example, that provides a frame that is achieves R-8; it can be installed with up to 300 mm (approximately 12") of mineral wool insulation (offering a bit less than R-4 per inch). Coupled with top-of-the-line AWS 90.SI triple-glazed windows that have a whole-window U-factor of 0.14), the system could meet Passive House standards. “We have the only aluminum Passive House window available,” asserted Steve Letourneau, director of operations at Schüco North America, although he acknowledges that a typical installation would most likely use the lower-priced AWS 65 and 75 series windows and less insulation.
New to North America
According to Letourneau, the ERC 50 Modernization Façade can be installed on buildings made from “brick, concrete, and pre-cast—or just about anything suitable for anchors and wind load.” The original cladding also has to be removed before installation, and engineers have to ensure the structure can support the load and that it meets local code restrictions. Adding the extra six or more inches around the perimeter of a building required by a basic ERC 50 system may not be possible in some dense urban areas, although Letourneau suggests that installing it eight feet above sidewalk level could help. And, as with any rainscreen façade system, proper detailing is critical to ensure long-term performance.
The ERC 50 Modernization Façade is brand new to North America, with no completed installations here yet, but the system was used to refurbish the 54,000 ft2 façade on the 1968-era, reinforced concrete Hans-Böckler Haus high-rise in Düsseldorf, Germany. The company installed the façade—removing the stone cladding, replacing the inefficient 0.53 U-factor aluminum windows, insulating the concrete on the building, and installing automated solar shading (a European option not available in North America)—in five months. The original cladding was saved, cleaned, and reused in the new façade.
“It’s a really impressive system,” commented Ralph Dinola, executive director of the New Buildings Institute. “Across the U.S., there are so many ‘vanilla’ buildings that may be old but are not historic,” he said. “We need to have a retrofit strategy for these old curtainwall systems.” So although Schüco’s system can incorporate existing elements—as with the cladding on the Hans-Böckler Haus—while leaving interior finishes largely untouched, “This system is for the 90% of other buildings that are not historic,” said Dinola. “It is going to change the building aesthetics quite dramatically, but a lot of owners would be very attracted by that.”
Schüco claims its system is cost competitive with other façade retrofit solutions, with the added benefit that occupants do not have to vacate the building for the façade and window replacement, which could avoid lost rent revenue. “In Washington D.C., they are replacing facades, but they are having to take the entire building apart to put the new façade on,” Dinola said, “which requires taking everyone out of the building.” With Schüco’s system, they can work floor by floor, and in the case of the Hans-Böckler building, occupants were displaced for only two days for window removal and trim. According to Letourneau, the Schüco system is also more streamlined than other systems that require additional supports, sealing of pre-existing window openings, and integration of products from multiple manufacturers.
The ERC 50 system not only gives buildings a second lease on life but also gives them the ability to adapt to changing energy codes and aesthetics. Windows can be upgraded and panels can be replaced if different colors or materials are desired. And when the building is eventually disassembled, the façade can be easily removed. By creating a modular system that integrates a number of window and façade components, Schüco has simplified the process of renovating a building exterior from the past and provides the tools to help keep it functioning into the future.
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