The east façade of the Health Sciences Education Building rises like a desert mesa. “The building is essentially a rock, an earth form,” says CO Architects’ Arnold Swanborn, who worked with Ayers Saint Gross and German climate engineering firm Transsolar in choosing the most efficient building orientation and shape.
Bill Timmerman The east façade of the Health Sciences Education Building rises like a desert mesa. “The building is essentially a rock, an earth form,” says CO Architects’ Arnold Swanborn, who worked with Ayers Saint Gross and German climate engineering firm Transsolar in choosing the most efficient building orientation and shape.

In Phoenix, temperatures can hover above 100 F for six months of the year. It seems natural then that for its project with the Arizona Board of Regents, Los Angeles–based CO Architects found inspiration for its design and cooling strategies in the surrounding desert and canyons. Located on the Phoenix Biomedical Campus, the six-story, 268,000-square-foot Health Sciences Education Building (HSEB) looks like an urban mesa, incised with self-shading fissures and a slot canyon courtyard topped by a polytetra­fluoroethylene fabric roof, which blocks rain and diffuses sunlight, reducing courtyard temperatures by as much as 20 degrees on hot days.

The building’s faceted copper skin likewise serves a dual purpose, giving the HSEB its distinctive color and texture while improving energy efficiency. During field trips to canyon country to study different desert microclimates, the designers were struck by the slot canyons’ aesthetics and noticeably cooler temperatures, says Arnold Swanborn, AIA, an associate principal at CO Architects and the project’s senior design architect.

Wall section
Wall section

CO Architects thus designed a skin of custom-fabricated panels to reflect the colors and arrhythmic striations of the region’s canyons. Arizona is copper country, which made the metal a natural choice, though the team used recycled copper from Rome, N.Y., rather than local virgin copper. Horizontal pleats in the copper panels resemble the sedimentary striations seen in the canyon walls, but they also reduce direct sunlight much like the self-shading vertical ridges of the saguaro cactus.

Early in the design and development phase, CO Architects brought on Chandler, Ariz.–based fabricator Kovach Building Enclosures. “We wanted to use them as a resource,” Swanborn says. The collaboration allowed the team to optimize a skin design that uses 16-gauge copper coil in standard widths. Laid in a running bond pattern, the 11-foot-wide panels have 26 unique designs and vary in pleat size and heights of either 12, 18, or 30 inches tall. Thanks to modularity and a stroke of planning luck—the early purchase of 250,000 pounds of copper at a rock-bottom price—the team slashed 48 percent off the façade’s original estimate.

The nearly 6,000 panels took nine months to fabricate and seven months to install. Each panel was bent in a press brake, a punch-and-die machine tool. “The only part of the skin that wasn’t custom made was the screws,” Swanborn says. The cladding doubles as a solar chimney, reducing the building’s cooling loads by wicking hot air up and out of the envelope through a 4-inch air cavity behind the panels. Half-inch vertical joints between panels allow thermal movement in the vast field of copper.

The horizontal ridges in the copper panels mimic the vertical pleats of the saguaro cactus. The 11-foot-long panels come in 26 different repeating panel designs, each varying in height—12”, 18”, or 30”—and pleat size. The panels are laid in a running bond pattern (to avoid vertical pin stripes).
Bill Timmerman The horizontal ridges in the copper panels mimic the vertical pleats of the saguaro cactus. The 11-foot-long panels come in 26 different repeating panel designs, each varying in height—12”, 18”, or 30”—and pleat size. The panels are laid in a running bond pattern (to avoid vertical pin stripes).

The copper panels clip to vertical steel girts, which are attached to a metal framed stud wall. A 4-inch air cavity separates the panels and the structural concrewall. Inboard of that gap is a 4-inch layer of mineral wool insulation protecting an air-and-water membrane, which is adhered to glass fiber-faced gympsum sheathing.
Courtesy CO Architects The copper panels clip to vertical steel girts, which are attached to a metal framed stud wall. A 4-inch air cavity separates the panels and the structural concrewall. Inboard of that gap is a 4-inch layer of mineral wool insulation protecting an air-and-water membrane, which is adhered to glass fiber-faced gympsum sheathing.

The Tempe, Ariz., office of Ayers Saint Gross and German climate engineers Transsolar were crucial partners in helping choose the most efficient site orientation and building shape. The building’s glass-enclosed ground floor space sits back 40 feet from the building’s façade, creating a self-shaded portico inspired by Native American cave dwellings in the Southwest. Slanted copper screens offer further sun protection; they are perforated and arranged at an angle that gives occupants on the second floor views of the greenspace to the west. Windows along the south elevation (shown) fill offices, classrooms, and laboratories with natural light.
Bill Timmerman The Tempe, Ariz., office of Ayers Saint Gross and German climate engineers Transsolar were crucial partners in helping choose the most efficient site orientation and building shape. The building’s glass-enclosed ground floor space sits back 40 feet from the building’s façade, creating a self-shaded portico inspired by Native American cave dwellings in the Southwest. Slanted copper screens offer further sun protection; they are perforated and arranged at an angle that gives occupants on the second floor views of the greenspace to the west. Windows along the south elevation (shown) fill offices, classrooms, and laboratories with natural light.

This is the third and final mock-up by Kovach Building Enclosures. In the previous iteration, Kovach presented a roll-formed panel design, but the straight lines looked too uniform. Kovach and CO Architects resolved the issue by angling some pleats across the panel faces, which meant each panel had to be bent individually in a press brake (a punch-and-die machine tool) at the Kovach plant 20 miles away in Chandler, Ariz. It took Kovach nine months to fabricate nearly 6,000 panels along with copper sunscreens, fins, and other finish pieces. Kovach delivered panels as they were made, allowing an on-site crew to install them. The process took seven months.
Courtesy CO Architects This is the third and final mock-up by Kovach Building Enclosures. In the previous iteration, Kovach presented a roll-formed panel design, but the straight lines looked too uniform. Kovach and CO Architects resolved the issue by angling some pleats across the panel faces, which meant each panel had to be bent individually in a press brake (a punch-and-die machine tool) at the Kovach plant 20 miles away in Chandler, Ariz. It took Kovach nine months to fabricate nearly 6,000 panels along with copper sunscreens, fins, and other finish pieces. Kovach delivered panels as they were made, allowing an on-site crew to install them. The process took seven months.

Small fissures in the structure’s north and south (shown) wings minimize the desert sun’s direct glare while flooding the spaces below with natural light.
Bill Timmerman Small fissures in the structure’s north and south (shown) wings minimize the desert sun’s direct glare while flooding the spaces below with natural light.