OHSU Center for Health and Healing

In December, the Oregon Health and Science University of Portland completed its third new building of 2006, the $145-million Center for Health and Healing, signaling a major advance for the city, the university, and the surrounding neighborhood. The 16-story, 400,000 high-rise with research labs, patient care facilities, a health club, and office space is being touted as one of North America’s largest and most progressive green structures. In March it received the US Green Building Council’s LEED Platinum rating, the first health care facility in the country to reach this status.

The center has an economic significance as well, being the first commercial building to go up in the South Waterfront. The new district will be 20 blocks of mixed-use high rises in southwest Portland located down a steep hill and across the freeway from the OHSU campus. An iconic half-mile aerial tram connects the new center to the rest of campus, shuttling passengers up and down the hill every 5 minutes like a European ski gondola.

Every building in the South Waterfront district will be LEED Silver, as part of the city of Portland’s purchase agreement with principal developers Gerding/Edlen and Williams & Dame. The Platinum status of the Center for Health and Healing, say project managers, was a result of the snowballing of creativity among the design team, who had started out to achieve Silver. In the end, the building’s energy use is 60% less than code requirements, and its potable water use is 54% less, setting an unprecedented standard for a building of its size in the Northwest.

Andy Frichtl, lead engineer on the project for Portland-based Interface Engineering, said one of the most remarkable aspects of the project is the fact that its development and construction costs were almost exactly the same as a similar structure built to traditional code. The development budget was $145.5 million, and includes as many green construction “extras” as the team could work in.

According to Dennis Wilde, project manager for Gerding/Edlen, the total cost for those extras came to $1.8 million. Tax credits and incentives for green initiatives, however, took $1.2 million off the development cost, and when the building was certified Platinum last month, it picked up yet another $600,000 in tax credits. Going forward, he said, the building saves $500,000 per year in energy costs.

“Everybody should do this kind of thing,” Wilde said. “It just makes good business sense.”

In one of the more radical additions, the building has its own on-site sewage treatment plant that recycles all of the wastewater emerging from the building, including the medical waste, sewage, and stormwater. The plant is located in the below-grade parking levels and is essentially a scaled down version of a typical municipal plant, processing 4,000 gallons per day. It employs waste-consuming bacteria in a bioreactor system, and produces water that is just less than potable. The treated water then enters a separate plumbing system, where it either discharges to the Willamette River or cycles back to the building for purposes like heating, cooling, landscaping, and filling the building’s toilets.

The plumbing system also collects all the rainwater falling on the site as well as groundwater pumped from the underground parking garage and adds them to the same supply. In one odd result, complying with Oregon state law on non-potable water use meant the designers were obligated to place signs above the toilets warning users not to drink from them.

“I think this is probably the most integrated of green structures to date in North America,” Frichtl said, referring to the way the mechanical, electrical, and plumbing systems interact with each other to save energy, water, and as often as not, money. “It’s more sophisticated than buildings used to be.”

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The design team eliminated more of its boiler needs by adding heat recovery to every heat source in the building, such as the chilled water units and lab exhaust. On the top 2 floors, they made use of natural sunlight by designing a “trombe wall,” which consists of low-iron glass enclosing a 4-foot wall cavity along the length of the building. The properties of the glass help accentuate a greenhouse effect inside the space, which raises the air temperature by a few degrees and is enough to heat water at a rate of 530,000 BTUs per hour. Double insulation keeps the office space on the floors from heating up as a result.

“Every degree you get is free heat,” said Brad Jenks, project engineer for contractor Hoffman Construction. “So even a degree is still savings.”

During the design phase, the team built a model of the building and the projected structures that will surround it in order to map out the sun exposure at all times of the year. From that, they were able to determine how much natural light they could use to replace electrical lighting, and designed the interior space to get as much sunlight penetration as possible. To help mitigate the glare and excess heat, they put in moveable sun shades on all the windows above the 4th floor.

The sun shades hang out at an angle from the building wall, and double as a platform for 364 photovoltaic panels that generate a total of 60 kW of power for the building, equivalent to one of the microturbines. Frichtl said the team had at one point considered a windmill on top of the building, but decided against it as costly and inefficient.

The passive approach translates to the HVAC system as well, which uses a variety of emerging techniques to supplement traditional forced air. The stairwells on two sides of the building, for example, use natural ventilation, since keeping a tight temperature range there is not considered critical.

Some locations use displacement ventilation, which works by putting cool air into the bottom of a room that displaces the heat and contaminants and pushes them out a vent at the top. In other areas, an emerging technology called “chilled beams” creates the opposite effect by placing a cool surface at the ceiling and generating a convection current with cool air falling and warm air rising. That application represents perhaps the first extensive use of chilled beams in the US to date, although the technology has been widely used in Europe.

On the ground floor, the team made use of the concrete foundation slab by running water pipes through it to create a radiant heating and cooling system. Thanks to the thermal properties of concrete, the slab can maintain air temperature throughout the lower-level atrium and the first few floors, and the water comes, naturally, from the building’s sewage treatment system.

The net effect of these various passive air handling alternatives is that the overall HVAC system is a tenth the size by volume of a traditional system, with fewer fans and less duct work and mechanical space between floors. The electricity needed for the system, meanwhile, is cut by about a third.

“We did a lot of stuff that makes sense for this project,” Frichtl said. “The chilled beams worked well for us, and I think they will be widely applicable. We’re starting to see people doing more of that, after seeing them on this project.”

Throughout the process, Frichtl said, the design team focused intensely on putting together exactly the right combination of green features for the building and the location. Where typical code structures tend to make a lot of room for safety in heating, cooling, and energy use, designing the OHSU building green meant cutting the safety margins and calculating the building’s needs precisely. During the course of the project, Interface made 12 appeals to the building code, and won 11.

“On a typical project we would get one appeal, maybe,” Frichtl said.

For Interface, green construction can still improve by making further cuts in energy use, and the company is currently working on other projects that seek a zero net energy draw from the power grid. Still, the sheer number of green features on the Center for Health and Healing has made it a milestone in green construction nationwide.

All the materials in the project are carefully chosen for their green qualities, whether recycled, locally produced, or low in toxins and energy use. Low-VOC carpeting and paints, high-efficiency windows and light fixtures, recycled drywall, wheatboard cabinets, and bulletin boards made from strawboard all appear on the building. Half of the wood, such as on the floor of the basketball court, is certified by the US Forest Stewardship Council.

“Steel and concrete are inherently LEED-compliant, because they are both locally produced and recycled,” added Jenks, the Hoffman project engineer. The building has large amounts of concrete for its thermal insulation properties. Steel was provided by Fought, concrete by Glacier Northwest.

Even the swimming pool, hot tub, and therapy pool on the second floor are progressive, Jenks said, as they are purified with salt rather than chlorine. They also act as a heat sink for the building’s overall energy conservation system. When there is excess heat in the system, it gets dumped to the pool to raise the temperature by approximately a degree, and can then be recovered as water vapor.

And among everything else, Interface says about $20,000 per year is saved simply by making sure all the lights get turned off. That is facilitated by sensors throughout the building that lower lighting levels based on the amount of natural light in the room, and motion detectors that shut off the lights when the room is unoccupied. Viewers from outside will be able to watch as the lights follow users up and down the stairwells.