The Gerding Theater in Portland, OR, is more than a mere model of sustainability. The Platinum LEED-rated building happens to have been originally built in 1891 as the National Guard Armory, so it has some history, too. On top of that, it's an innovative, compact adaptive reuse that serves its community in the Brewery Blocks neighborhood with world-class technology for building operations and theatrical performances.
When listing the notable achievements embodied by this unique project, it's hard to decide where to start. (See LEED Platinum, Historic Register: A Checklist) But, clearly, the project established the fact that super-green buildings can also be listed on the National Register of Historic Places. Says Ralph DiNola, LEED AP, principal of Green Building Services, Portland, OR, which served as a consultant to the developer on sustainable building and the LEED process, "We learned you don't have to compromise on one to do another; they can work really well together to green a historic building."
How they got there was by no means a direct path. For example, the suitability of the armory as a world-class theater space was never taken for granted. At first, developer Gerding Edlen Development of Portland, OR, considered the single-story structure and its open, warehouse-like space ideal for an athletic club. Yet, the historic armory's location at the core of the burgeoning Brewery Blocks redevelopment zone - amid the trendy Pearl District - called out for a cultural nexus like Portland Center Stage, which was seeking a home. For the Brewery Blocks, it would be an added attraction for new residents and retail businesses.
"The developer was really wanting to have a significant green building aspect to make this a truly signature project, and they wanted to preserve the historic character as much as they could," says DiNola.
After settling on the kind of reuse, a second hurdle was decidedly nonarchitectural. As with many adaptive reuses of landmarks, they had to make the budget work. "Old buildings don't typically make economic sense to redevelop, and, 4 years ago, applying for LEED certification seemed like a stretch," says Norris Lozano, president and CEO of the Portland Family of Funds, which arranged the project's financing. "Though it may have been theoretically cheaper to tear down the old armory, we used three kinds of tax credits to reduce the costs dramatically."
One of those, the New Markets Tax Credit, helped underwrite the innovative approaches that would make the new theater world-class green. According to Lozano, "They actually drive you to push the envelope in terms of what you can do about efficiency, rehabilitation, and historic preservation."
Push the envelope they did - including pushing down into the earth below by excavating some 30 feet deep near an adjacent high-rise, requiring careful shoring techniques to protect the building's original foundations and 30-inch-thick brick-bearing walls. The reason, explains architect Alan Beard, FAIA, principal-in-charge for GBD Architects of Portland, OR, was so the project team could retrofit the half-block-sized floor plate with an internal, box-shaped concrete structure. This inner shell would serve as both seismic bracing and acoustical isolation for the performance and rehearsal spaces. By choosing to dig down, the architects also were able to squeeze in 55,000 square feet of program space, including the main stage, a black-box theater below, and a large rehearsal hall above.
"It was like building a ship in a bottle," says Beard, whose firm has built 14 LEED-certified buildings, including six rated Gold. "We preserved 200 feet by 100 feet of column-free space with wonderful parallel-chord bowstring trusses with tie rods at the bottom. In fact, the office space is up amongst those trusses."
Recycling about 75 percent of the original armory structure contributed to LEED certification, but it was only one of dozens of techniques the team used to "green" the adaptive reuse. For example, the contractors reclaimed and recycled more than 95 percent of the construction and demolition debris. Overall, however, this proved to be one of the biggest challenges Beard has ever faced. "Trying to satisfy the programmatic elements and the requirements of the National Parks Service - and the U.S. Green Building Council's system to get a LEED Platinum rating - the complexity is mind-boggling," Beard recalls.
Success through Technology
Beyond building recycling, the major greening moves were about bringing light and air into a former armory that served for 3 decades as a beer-keg warehouse. Now it would have staff workers, performers, and large crowds every night. Its gun-sight windows and damp, cavernous interior wouldn't provide enough daylight and fresh air to meet LEED standards for healthy indoor environments. Fortunately, the original roof was well hidden behind a parapet so that skylights and a rainwater catchment system could be added without visibly affecting the historic Romanesque Revival exterior. The skylights allow daylight into administrative areas and the double-height lobby; the catchment system brings in gray water for use in the low-flow, dual-flush bathroom fixtures.
The HVAC approach was hardly as straightforward. The architects, with engineers from Portland, OR-based Glumac, tactically applied a mix of displacement ventilation, radiant flooring, and occupant-controlled chilled beams to regulate temperature and air quality on a highly localized basis. This approach would prove very efficient. Other energy-saving features would include daylight controls, occupancy sensors, and specially selected materials.
For visitors to the theater, these comforts and efficiencies are mostly imperceptible. What they see are the big design moves. The entry and lobby are marked by ample illumination, either from the skylights with their advanced glazing systems or from the monopoint pendants, as well as a custom decorative chandelier and an artistic lighting installation called the Fire Wall. All of these decorative fixtures are fitted with dimmed halogen lamps that add a theatrical sparkle to the entry sequence.
The staff enjoys similar benefits. "We integrated the daylighting and electrical lighting in the entry lobby, and on the top floor in the administrative level, with photosensors to dim local lighting as well as user-controlled dimming in the more open office areas," says Ben Watson, a lighting designer with Glumac, which engineered the mechanical and electrical systems.
According to Watson, almost all of the general illumination is provided by dimmable compact and linear fluorescent fixtures, except for the lobby halogens. "Open-loop" photosensor systems - which measure daylight levels outside the skylight and windows - are employed along with "closed-loop" sensors, measuring reflected light levels coming off the work plane. In the open offices, a semidirect pendant fixture with T5 and T5 HO lamps bounces 20 percent of its illumination off the trusswork and ceilings; the rest spills down through a blade louver.
Another of the linear fixtures will surprise many American architects: The large, metal-shrouded units incorporating the same pendants are actually localized HVAC systems, replete with heating and cooling coil. "The chilled beam is a mechanical system that heats and cools the volume of air around a person, somewhat like a radiator," says Watson. "The units are very visible and very large, so we used a recessed lens fixture, which the manufacturer incorporated into the chilled beam."
This process required a good deal of cooperation between the British maker of the chilled beams and the U.S. lighting manufacturer, but the team found it was worth it. "In the end, it worked out very well," says Watson.
Active Beams and Displaced Air
The "active" chilled beams - so called because they incorporate both heating and cooling - are steadily gaining a market in the United States, says Bob Schroeder, PE, a mechanical engineer with Glumac. "We have a raised floor there, but it was limited in height in office areas, so to supplement cooling and provide heat, we integrated the active chilled beams," he says.
While the chilled beams efficiently add occupant-controlled comfort, a more common green technology comfortably automates HVAC efficiency: "We employed CO2 sensors for the air-handling systems to allow for demand ventilation in all occupied spaces," says Schroeder. "Whether backstage, in the theater or in the lobby, or rehearsal halls, the spaces have big swings in terms of population. The sensors are very important in terms of not bringing in excessive amounts of outside air."
Systemwide, another sensible approach was to employ displacement ventilation in the theater, which essentially introduces conditioned air below theater-goers' seats. The air naturally rises as it warms, drawing in more supply. "A lot of theater HVAC solutions introduce air overhead, and with the catwalks and lighting loads, you have to blow at much higher velocities" - also a source of unwanted noise in a theater venue, Schroeder explains. In this case, the concrete inner structure created within the armory shell served as a perfect underfloor distribution plenum. "We didn't have to build any other elements," he adds.
Despite the unusual mix of HVAC technologies - all tied together by an energy-management system with measurement-and-verification capabilities (a LEED credit) - the super-efficient operations are largely attributable to Portland's cool weather and the old armory's thermal mass. The existing deep brick shell did not even require insulation on the inside walls; the brick, along with the new concrete floors and walls, serves as a "thermal flywheel" to reduce diurnal temperature swings. The special glazings in the skylights and windows maximize daylighting while controlling passive solar heating and minimizing seasonal heat losses and gains.
In addition, the Gerding Theater is tied into a district chiller plant on the roof of a nearby former Chevrolet dealership that now houses a Whole Foods grocery. "The chiller plant provides low-temperature chilled water to all five of the Brewery Blocks through an underground garage, which contributes to the energy efficiency of the theater," says David Posada, LEED AP, GBD Architects' sustainability coordinator. The district plant also helped make the theater arts facility physically efficient by obviating the need to squeeze a large chiller into the theater - or atop its landmark roof.
Opening Night
The theater opened in October 2006 to sellout crowds for not only its premier performances by the Portland Center Stage theater company, but also to Portland community groups and individuals who now could access an unusual resource. "The most powerful aspect of the project is that it is open to the community every day, which is actually quite rare," says Lozano. "It's accessible to everybody, including the café on the ground level and the pocket park on the side."
Beard agrees, adding, "For all of us, this became a truly significant opportunity to save a truly significant building. And we were able to save it and turn it into something that everybody would enjoy. Now, people come in and say, ‘Wow, this is very cool.'"
Some observers may note that the greatest singular accomplishment was to make a historic landmark also work as one of the highest-rated green buildings in the land. Through a mix of technology, recycling, and natural amenities, the Gerding Theater became not only efficient, but also an enjoyable place to work, perform, and enjoy the stage. "It was a huge design challenge; at the beginning, people were very skeptical," Lozano admits. "Now when they go into the building, they are really convinced."
C.C. Sullivan ([email protected]) is an author and communications consultant specializing in design and construction.
Products used:
Chilled beams: Trox
Photocells and integrated lighting control system: Electronic Theater Controls (ETC)
Lighting switching system: PCI
Linear fixtures: A-Light
Occupancy sensors and photocells: Watt Stopper/Legrand
Energy management system: Siemens
