The Westminster Presbyterian Church expansion project in Minneapolis is designed to connect the church’s 1895 Romanesque architecture with a new modern, light-filled space for the community to enjoy for the next 150 years.

Glazing and metal contractor Empirehouse Inc., based in Mounds View, Minn., won the Minnesota Construction Association’s (MCA) subcontractor/specialty contractor award at the MCA Awards of Excellence Gala on January 31 for its part in the Westminster Presbyterian Church expansion.

The company teamed with general contractor Mortenson Construction and architecture firm James Dayton Design as the architectural glass and metal contractor and design-assist partner. Unique features included a 30-foot wide domed skylight, oversized sliding aluminum-framed glass doors, folding glass walls for sound control and dichroic-filmed curtainwall to simulate modern stained glass. The project includes a total glass area of approximately 11,000 square feet.

Empirehouse worked with Mortenson to develop a safety rig line configuration to hand set 9,000 pounds of glass within the skylight frame four stories above ground.

“Empirehouse was selected … based on our innovative approach toward some of the more challenging design elements. Our input on these custom elements helped to ensure the project would be delivered to meet the scheduledand maintain the specified budget,” says Patrick Lawrence, Empirehouse director of sales and marketing.

His first impression of the project was that it is very complex with multiple façade systems integrated into the design.

“In addition to standard aluminum and glass systems, the project incorporates three separate monumental design elements that create an open and inviting environment,” says Lawrence. “The high-span curtainwall provides an unobstructed view of the architecture of downtown Minneapolis, while the oversized dome skylight floods the central stair with natural light. The jewel of the expansion, the point supported structural glass fin wall, was covered in dichroic film that creates an explosion of light inside the gathering spaces.”

Oldcastle Building Envelope® supplied the vertical glazing systems, custom dome skylight system, standard slope glazed skylight systems, point-supported structural glass wall systems, aluminum curtainwall and entrance systems for the Westminster Presbyterian Church expansion. The glass is clear with a Vitro Solarban 60 coating.

For vertical glass applications, the point-supported structural glass wall system included glass as large 42 inches by 148 inches. The custom domed skylight frame was crowned with a 481-pound center flat oculous insulating laminated glass lite which spans 84 inches wide.

There were a number of unique glass and metal challenges. These included assembly access of the metal framing, and glazing a 30-foot wide by seven-foot tall custom dome skylight to be placed over a four-story staircase. The solution was to assemble the 4,500-pound skylight metal framing on a steel lift ring which was tower-craned over the fourth floor opening.

Then a safety rigging was engineered for the glazing team of four to hand install 9,000 pounds of glass units into the skylight over the fourth floor opening.  Today’s safety standards require fall protection tied to a 5,000 pounds per person anchor point.

Completed structurally glazed point-supported system treated with a dichroic-film application.

Another challenge was installing a structurally glazed, point-supported system with a surface-applied dichroic film. Glass units, as large as 44 inches by 136 inches, were point-supported with spider fittings, which meant that the glass needed to be filmed in Empirehouse’s production facility before being loaded, transported, unloaded, craned and glazed into the opening without applying too much pressure on the dichroic film.

Before the film was applied, Empirehouse worked with Mortenson Construction and James Dayton Design to determine where to place the dichroic film in order to showcase its full range of color as the sun shifts across the room each day. Once placement was determined, the dichroic film was applied to each 4- by 11-foot, 350-pound glass unit in the production facility before being transported to the jobsite for installation.

Empirehouse provided design assistance to determine the fin dimensions, whether the fins would be visible or recessed, whether the system would be base loaded or top loaded, address the live load in the roofing, and develop a structural steel mechanism to anchor the structurally glazed point-supported system and accommodate roof deflection upon the arrival of snowy winter months.

Another curtainwall system had a fly-by condition at the ends with no structural support behind it or at the head. Through engineering and design-assist innovation, steel was used within the system to accommodate the load transfer and secure the glass and framing.