Above: CO Architects topped Cal Poly Pomona’s Student Services Building with an undulating, 2-acre standing-seam aluminum roof that spans two structures totaling 140,000 square feet.

Undulating aluminum roof shelters students and faculty with energy-efficient design

September 2020 - California State Polytechnic University Pomona (Cal Poly Pomona), part of the sprawling state university system, sought for years to build a new Student Services Building but budget constraints dashed those hopes for a while.

In 2019, however, the dream was realized when the school opened a 140,000-square-foot facility that consolidates enrollment, registration, financial aid, cashiering and prospective student services into one-stop service centers adjacent to administrative functions.

The main structure encompasses 100,000 square feet across three stories with another 40,000-square-foot two-story “wing” across a breezeway. CO Architects in Los Angeles won the bid to design the Student Services Building and had to stay within a strict $60 million budget that was approved back in 2010.

CO Architects topped the SSB with an undulating, 2-acre standing-seam aluminum roof that spans the two structures. The shape and orientation of this feature is driven by performance and function—to optimize energy management, maximize daylight and offer views of the surroundings.

Land grant - The Pomona campus “used to be the Kellogg family’s winter ranch, which bred Arabian horses,” says Alex Korter, associate principal with CO Architects in Los Angeles. “The Kellogg Foundation deeded the land to the California State University system to create a new university. The historic horse stable remained, and the school still breeds Arabian horses.” Before land use changed significantly, “this area of Southern California was full of citrus groves. It is a beautiful setting against the San Gabriel Mountains to the north,” the architect notes.

Antithesis of hierarchy

The new building replaces the triangular CLA building to the north, says Alex Korter, associate principal with CO Architects, Los Angeles. “We started with a campus survey of faculty, staff and students, and they wanted something less hierarchical and more representative of the campus. We went with the antithesis of the tower—a low-slung, egalitarian building. Something that was collaborative, not just where you meet administrators in the elevator.”

In addition, “it had to provide access daylight and views to occupants and relate to the context and topography of the mountains beyond. So we wanted movement in the roof.

“We also sought to bring the energy usage down as much as possible. The roofing is the main energy use-reduction performance driver,” Korter says. “It acts like a big umbrella. When it gets 100 or 110 degrees in the summer, everybody is looking for shade. We wanted to make sure it protects the building and campus community.”

CO Architects chose the Kalzip roofing system. Started in Germany, the company has facilities in Valparaiso, Indiana, and Beamsville, Ontario. Korter says the choice was “natural, because we wanted something that was cost effective but would last a very long time. It would not be a maintenance burden. It could be versatile and it could be shaped.”

Regarding the paneling system, Korter says, “We enjoyed exploring an off-the-shelf material, molding it and testing its limits.”

CO Architects explored off-the-shelf material for the paneling system.

Light and shadow

The architects devised the roof as the primary performance driver for the curving building to achieve an advantageous Energy Use Intensity of 31 (the average at the time of design was 65). The roof ties the building to its context by referencing the topography of the campus, the foothills and the nearby San Gabriel Mountains.

The roof is the SSB’s primary shading device. The architects used extensive daylight, glare and solar heat-gain analysis models to optimize the roof geometry, minimize energy loads for lighting and cooling, and increase users’ visual and thermal comfort.

While shading the open pedestrian path between the two buildings, the roof’s perforated metal overhangs vary from 5 feet to 28 feet deep to protect the aluminum-framed, reflective glass exterior wall from the sun, filter dappled sunlight and optimize daylight to the interiors.

To achieve the complex curvatures of the Kalzip standing-seam roof, custom-shaped panels were fabricated on site using roll forming machines. The roof required 19,000 attachment clips to keep the panels in place.

Standing-seam roofs are “rarely as complex” as this one, according to Korter, whose firm has completed many educational and government building projects over its 30-year history. CO Architects has completed projects across California, Texas, the Midwest, Southwest and the East Coast, and is currently designing a building in Scotland.

“The work is mostly for mission-driven clients—higher education for science, technology and medicine. We started on medical education projects about 12 years ago and have become experts. We design a lot of hospitals, clinics and medical office buildings,” Korter says.

“We like very, very complex project typologies and push to find beautiful architectural solutions.”

Bird’s-eye view: The low-maintenance Kalzip roofing system is versatile and can be shaped, according to the architect.

3D design

The architectural firm uses digital technology, such as 3D and Building Information Modeling (BIM) tools. “This roof is almost impossible to document as a 2D drawing,” remarks Korter. “All the work was done in a 3D modeling environment. Support structures, small members, large members, bends—everything was created in 3D.”

CO Architects partnered with Kalzip as the panel fabricator and CMF Inc., an architectural sheet metal fabricator in Orange, California, as the installer.

“We worked with the fabricator collaboratively, and virtually, to optimize the shape and panelization—including straight standing seams, tapered paneling and XT-type, complex compound-curve panels. Each of those has a completely different geometry, and the fabricator took our geometry and extracted each panel shape while establishing the overall layout. That data was then extracted individually and fed directly into three roll form machines on site.”

One machine produced straight-seamed roofing, one specialized in tapered paneling and one produced only XT panels, he says. The digital method generated no printed drawings, with the exception of a topographical map for reference, meaning the process was essentially “completely paperless.”

The architectural firm uses digital technology, such as 3D and Building Information Modeling (BIM) tools.

Roll forming

Having the fabricator perform roll forming on site was very efficient in terms of cost and productivity, according to Korter. “Everything is predesigned in modeling before the coil arrives. We know how much length is needed. Panel lengths and geometries are predetermined.”

The perforation of the aluminum panels that act as overhangs allows for shading but daylight still enters office spaces, saving energy on lighting while still keeping the interiors relatively cool. “That’s partially how this building achieved a LEED Platinum rating. The building consumes less energy mainly because of the roof,” he says.

Aluminum has a high recycled content and “is extremely long lasting, including its coating,” says Korter. “It is under warranty for 30 years but you probably won’t have to touch it for 50 to 60 years.”

Cal Poly Pomona’s Student Services Building, opened in early 2019, won a 2019 Architecture MasterPrize and took top honors in the education category at the Los Angeles Business Council’s Architectural Awards. MM