Research Stories

by Adelheid Fischer

The new streetscape outside Phoenix Sky Harbor's Terminal 2 provides a cool and environmentally friendly shelter to travelers, while still meeting safety codes and disability standards: (photos courtesy Darren Petrucci)

In spring 2008, Darren Petrucci landed one of architecture's dream prizes. His VH R-10 gHouse on Martha's Vineyard was among nine international residences to win a coveted Record Houses award from Architectural Record magazine. Petrucci's island retreat is as trim, compact and elegant as a Shaker chest. Completed only a year ago, it has already graced the pages of several glossy magazines.

Projects such as the VH R-10 gHouse could pigeonhole Petrucci as a gentleman's architect. But nothing could be further from the truth. When it comes to design, the Harvard-educated director of the School of Architecture and Landscape Architecture at Arizona State University maintains a kind of dual citizenship.

Petrucci is as much at home in the sear and grit of urban streets as he is in the remove of a historic seaside village. Witness the work of SCAPE, the research and design studio that Petrucci founded at ASU. SCAPE stands for Systems, Components, Architectural Products and Environments.

As principal architect, Petrucci has tackled streetscapes that would make less visionary designers lose their will to live. And he has done so with award-winning results.

In 2002, for example, he snapped up a prestigious Progressive Architecture Award. The winning project was a revitalization plan for a jumbled, 1960s-era strip along Scottsdale Road in Scottsdale, Ariz. Four years later, he won the Prize for Creative Integration of Practice and Education in the Academy from the National Council of Architectural Registration Boards. NCARB cited Petrucci for his rejuvenation of ailing 7th Avenue in downtown Phoenix.

These days, Petrucci and SCAPE project architect Phil Horton have overhauled another messy holdout from the 1960s. Their task has been to renovate the streetscape outside Terminal 2 at Phoenix Sky Harbor International Airport.

Terminal 2 was sleek and modern when it was built in 1962. In recent years, however, it had begun to show its age. Especially sagging was the terminal's streetside exit.

During the hot summer months, travelers stepped through sliding glass doors into the spotlit glare of the desert sun. Heat radiated from the concrete buildings and asphalt roads. To catch shuttles and cabs, travelers dodged traffic to a narrow median.

Once there, they bumped and scraped luggage along an obstacle course of trash cans, utility poles, benches, fireplugs, and signposts. Planes roared overhead; buses and automobiles streamed perilously close on either side. It was the design equivalent of all-out urban warfare.

The street might have continued to function in its present form until 2012. That's when Terminal 2 is scheduled to be demolished and rebuilt. But the streetscape couldn't wait that long. In 2006, a disability check revealed that the cluttered outer curb failed to provide the necessary clearance for visitors in wheelchairs. It was time for a more functional and friendly redesign. Airport officials turned to Petrucci.

The design brief called for packing a wallop of features into a tight space

A mere 1,000 feet long and an average of five feet wide, the project appeared relatively straightforward. But it ended up being "incredibly difficult," Petrucci says. The design brief called for packing a wallop of features into a tight space. Each design move was constrained by a laundry list of safety and airport-security concerns.

The materials used to build pedestrian shelters, for example, had to withstand solar extremes while minimizing heat gain. Occupants needed to be sheltered from the sun and yet visible to airport security. At the same time, the shelter materials had to withstand damage from vandals and errant vehicles.

The narrow median strip also needed to supply electric lights, shade, water, and pedestrian seating. Yet three feet of wheelchair access had to be factored between each structural element and the curb.

In short, the design had to combine function with safety, comfort, and elegance. It was tall order for a budget of $1 million.

From the outset, Petrucci and Horton adopted two overriding goals. Simplicity was at the top of the list. And each design element was required to multitask.

"Lots of architectural moves would have complicated an already complicated space. We needed to create a quiet versus an emphatic space," Horton points out. "And the constraints were so tight that each part had to serve more than one function."

To serve these ends, Petrucci and Horton settled on hangman's scaffolding as the basis for their design. In this scheme, light poles were set at 30-foot intervals. The vertical poles supported horizontal spans of steel trusses. Signage boxes could be hung from this skeleton. So could perforated metal panels that provided shading and definition for waiting areas.

"Our strategy? We needed to have as few things touching the ground as possible in order to liberate the ground for wheelchair accessibility," Petrucci explains.

Keeping the space comfortable in the desert's extreme climate proved to be a challenge. For example, Petrucci and his colleagues used thermal-imaging cameras to photograph traditional metal bus shelters on the streets of Phoenix. Their measurements show that shelter temperatures can soar to more than 140 degrees F under the desert sun.

The ASU team scouted for ways to prevent the buildup of heat. For starters, Horton discovered a company in Wausau, Wisc., that could clad the project's metal screens with durable, insulating layers of a thermoplastic powder coating. The finish prevents the metal from conducting and radiating heat.

Specially coated screens prevent heat from building up in the roadside structures.

The team developed additional design strategies for coping with the desert sun. The metal panels, for example, were formed into a series of cascading pleats. The strategy eliminates the flexing and denting that can occur with large expanses of metal sheeting. The angled panels also create visual interest. At the same time, they shade one another from the hot desert sun, helping to reduce heat gain inside the shelters.

To further cool pedestrian shelters, the team specified evaporative coolers that could be activated with timer switches. Quiet and energy efficient, the units also recycle their own water.

Petrucci and Horton also kept comfort and elegance in mind when redesigning the seating for the project. The benches' bold, chiseled forms perch like sculpture along the median.

But unlike sculpture, the benches are designed with ergonomics in mind. Their hard backs provide superb lumbar support. And their angled pedestals allow people to tuck in their feet to open up floor space for moving pedestrians. Together, they also serve as a bulwark against cars that inadvertently jump the curb.

To avoid the heat gain of traditional concrete, the benches are precast in crumb-rubber concrete. To make this material, a portion of the sand used in mixing the concrete is replaced with rubber bits from recycled tires. Crumb-rubber concrete dramatically cuts heat retention. Its performance will be monitored by scientists from ASU's Sustainable Materials and Renewable Technologies (SMART) lab.

Best of all, the design is composed of integrated, modular units that can be dismantled and moved or repeated at other terminal locations. The units also are designed to be easily fitted in the future with sun-capturing photovoltaics.

"The real goal here is to create a unified, shaded scrim that establishes a new image for the airport. After all, terminals are the city's first chance to make a good impression," Petrucci says.

The streetscape design work for Terminal 2 was supported by the City of Phoenix and Sky Harbor International Airport. For more information, contact Darren Petrucci, School of Architecture and Landscape Architecture, College of Design, 480.965.3536 Send email to Darren.Petrucci@asu.edu