Parking Garage at Portland Int'l Includes Office Space & Green Features

The new combination parking garage/office building at Portland International Airport (PDX) in Oregon was designed to be an energy-efficient structure, and statistics from its first year of operation are bearing that out.

The top portion - 205,000 square feet of headquarters space for the Port of Portland - has an energy use index (EUI) of 42, compared to an EUI of 82 for a more traditional building of the same size, reports Steve Reidy, principal and vice president of PAE Consulting Engineers. (EUI is the energy consumed by a building divided by its total square feet.)

In more familiar terms, heating and cooling costs for the three-story office portion of the structure are projected to be 65% of those for a conventional building. The heating bill for the enclosed areas of the 3,500-space parking garage located below are projected to be just 22% of a conventionally built garage's bill. Lighting costs for the combined building are projected to be 70% of those for a conventional structure, thanks to energy-efficient fixtures and abundant use of natural light.

These and other sustainable features have earned the building at least six awards. In 2011, it also qualified for the U.S. Green Building Council's rare Platinum certification for Leadership in Energy and Environmental Design (LEED).

Encore Performance

The Port has an established track record of initiatives designed to decrease its carbon footprint and otherwise demonstrate sustainable practices, and officials wanted the new headquarters to set yet another high standard. "We have a long-standing environmental management system dating back to 2002, where we started looking directly at environmental aspects in our practices and building," notes Greg Sparks, Port of Portland project development manager.

The first seven stories of the structure house the long-term parking garage for PDX; the eighth and ninth floors are office space. The tenth floor, also office space, is set back from the two floors below it. The front "ship-lapped" wall of the building integrates the garage and office space.

"The Port was very interested in telling the story of who they are and what they do ... both aviation business as well as shipping. We developed ideas around the curve of an airplane wing, the bow of a ship, the lapping of hull planks, the verticality of a control tower and the rhythm of railroad tracks," explains Doug Sams, project architect with Zimmer Gunsul Frasca Architects.

factsfigures Project: Parking Garage/Office Building Location: Portland (OR) Int'l Airport Owner: Port of Portland Garage Size: 1.2 million sq. ft. Parking Spaces: 3,500 Office Size: 205,000 sq. ft. Occupants: Port of Portland headquarters staff Cost: $85 million for office space; $156 million for parking garage/terminal tunnels Funding: Working capital & airport revenue bonds Timeline: Dec. 2005 - May 2010 (design to occupancy) Lead Architect: Zimmer Gunsul Frasca Architects General Contractor: Hoffman Construction Co. Prime Design Contractor: Zimmer Gunsul Frasca Architects LLP Consultants: KPFF Structural Engineers; PAE Engineers - mechanical/electrical/plumbing design Estimator: Hoffman Construction Landscape Design: Mayer Reed Landscape Architects Survey: MING Survey Geotechnical: Geotechnical Resources & Environmental Consultants Parking System Management: Standard Parking Corp. Automated Parking Guidance System: Scheidt & Bachmann Revenue Control System: Scheidt & Bachmann Key Elements: Open-concept office space above public airport parking garage Benefits: Lower operating costs; green design Noteworthy Details: Living Machine wastewater treatment system; geo-exchange heating & cooling system coupled with passive radiant panel thermal comfort system; extensive glass & skylights; advanced lighting control; automated parking guidance & revenue control

One particularly green feature resides on the roof of the ninth floor, in front of the tenth floor. Here, a 10,000-square-foot "eco-roof" with a roughly 6-inch deep layer of planted soil absorbs rainwater and releases excess rain to the storm water system. The eco-roof helps keep the roof cool and reduces the heat island effect. Skylights flood the atrium and offices with natural light.

An open office concept, with 42-inch high partitions separating individual workspaces, combines green and social engineering. "There is no visual privacy, but it encourages easy access to people; and it has a huge impact on natural lighting reaching work spaces," Sparks explains. "People got used to it very quickly, and they appreciate the fact that they can turn their heads and see outside." The Columbia River, he notes, is visible from the north side of the building.

Down Under

The sole source of heating and cooling for the building begins deep underground, in 200 holes, each 340 feet deep and filled with piping encased by grout. The piping is part of a closed loop that circulates water through 400-ton chillers, heat exchangers and the 340-foot deep plugs of grout, which themselves act as heat exchangers with the 55º to 60º F earth. Another closed loop carries either warmed or cooled water to radiant panels throughout the building, heating or cooling it, respectively.

The team that developed the system calls it a ground source heat exchanger to distinguish it from geothermal heating systems. To cool the building, warm water (85º F, for example) is sent down into the holes and is delivered back up after it is chilled (to 65º F, for instance). To heat the building, cool water (35º F) is sent down and warmer water (50º F) is returned.

"The Earth is a heat source or a heat sink, depending on the time of year," Sparks summarizes.

According to Reidy, PAE was at the forefront of the new method. "But now, a lot of people are doing this," he adds.

All those holes, 1,500 pilings, giant trenches for two pedestrian tunnels, a new utility tunnel for chilled water, plant steam and an FAA duct bank made for a busy worksite. "The project was challenging from many perspectives, but the ground plane was probably the most challenging," Sams notes.

Waterworks

The building was designed with efficient plumbing and a recycling system called the Living Machine to cut water consumption by about 80%.

The Living Machine, by Worrell Water Technologies, is a twist on traditional septic tanks and fields. The system includes a buried septic tank and a series of aboveground tanks the company calls tidal flow and vertical flow wetlands. Black water, minus solids, is progressively pumped and purified by plants and bacteria in the tanks and then reused to flush toilets.

Some of the tanks are inside the building. In addition to serving as a visible demonstration of the airport's green technology, they, in effect, act as vegetation-covered planters.

Value Engineering

"Lifecycle cost analysis was an important part of the process for the project team," specifies Sams. "This included not just the sustainable energy and water strategies, but also included the interior and exterior building material and aesthetic choices ... We believe this attention to detail allowed us to achieve the Port's goal of an iconic structure on a very tight construction budget."

That said, the Port also wanted to promote the state's reputation for and commitment to sustainability. "Some sustainability features were not subjected to value engineering," qualifies Reidy.

Sparks considers the garage/office hybrid at PDX one of the greenest buildings the Port of Portland has ever constructed. He also expects it to be a trendsetter: "We set a very high bar ... It will influence future buildings for us and for the region."

Putting a Face on Automated Parking When officials upgraded the parking management systems at Portland International Airport (PDX), they circumvented the man vs. machine debate by choosing both. The resulting combination - automated systems for parking guidance and revenue control plus a human staff of 60 - strikes the right balance between cost-saving automation and personal service, explains Michael Huggins, PDX landside operations manager. "We get a lot of positive feedback via our website," Huggins reports. "Our business travelers are constantly talking about how great the system is, how it saves them from missing their flights." The automated guidance and revenue control systems, installed and operated by Scheidt & Bachmann, reduce staffing costs by directing drivers and processing credit card transactions (87% of the airport's total parking receipts). The automated wayfinding system uses electronic reader boards to direct drivers to floors and then stalls with available space in the short-term parking garage. Scheidt & Bachmann is also designing an extension of the system for the long-term garage. "This is a high-level service that gives passengers peace of mind," says Huggins. "It makes it easier for them to get parked and inside the terminal so they can enjoy their experience there." It also increases efficiency, he adds, because parking stalls are less likely to go "unfound and unused." On average, the system handles about 6,000 transactions daily, with frequent peaks of 8,000 or more. The key to the system's high level of acceptance is the human interface between the system and drivers, relates Pamela Brown, vice president of business development - airports for Standard Parking Corporation. "PDX realized support was important and that they needed real people in front of the customers," Brown explains. "They understood that you don't just install it and they will come." Standard Parking, which has held the parking management contract at PDX since 2006, employs those people: about 30 frontline staff to assist drivers and another 30 working behind the scenes, monitoring the health of the system, tracking revenues and paying the bills. Workers in its operations center field customer calls 24/7 - helping find lost cars, completing transactions without tickets and educating drivers about using the system. Cameras and an intercom system near the pay-on-foot machines expedite help with simple issues such as inserting tickets the wrong way, adds Dave Hellerud, Standard Parking's general manager at PDX. Automated assistance begins on the airport's website, where maps, rates and a "fill-level" gauge for each parking area help passengers plan their parking strategies. During holidays, the airport displays messages about parking on its over-the-road signs as visitors enter the airport. PDX provides parking in a short-term garage, long-term garage and an economy lot - 14,130 slots in all.