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It’s dark. It leaks. There’s mold in the walls. The floors sag. There’s debate whether it’s ever met seismic code.

There are many issues with the Portland Building, the 35-year-old downtown city administrative hub and architectural landmark. And quite a few relate to the building’s unique exterior.

A began recently to gut and rebuild the interior while preserving the building’s iconic look. The chosen team of DLR Group and Howard S. Wright went public with their conceptual design plans in December and lately has been working on the details. Undergirding their efforts will be help from one of the world’s leading experts.

Michael D. Lewis, architect and structural engineer, is regarded as a building envelope ace. (One source called him 鈥渢he Michael Jordan of building enclosures.鈥�) His Cincinnati firm, Facade Forensics, has done much design and rehabilitation work on hospitals and museums, in particular 鈥� any place with an extremely sensitive interior.

Lewis has consulted for, among others, the National Gallery of Art in Washington, D.C., and has shored up the work of numerous noteworthy architects 鈥� including several projects by Portland Building-designer Michael Graves.

It’s a misconception that the Portland Building’s roof leaks, Lewis said. In fact, the sides 鈥� particularly the window systems 鈥� have allowed water intrusion. (The roof was recently replaced.)

Leaky windows aren’t the only issue. The Portland Building was built at the height of the energy crisis in the 1980s, and to save money, cash-strapped designers made a number of decisions that have come back to haunt the city, according to Carla Weinheimer, a DLR Group partner. These include the amount and type of glazing.

Many of the punched openings that appear from the outside to be windows, are actually panels of black spandrel glass. All will be replaced with insulated, single-pane glazing units. This effort adheres to a mandate to improve daylighting in the dank office tower. The new glass shouldn’t affect the look of the building, which is a necessity because it’s on the National Register of Historic Places.

鈥淢y thought has been: 鈥楬ow do we make this thing come alive?’鈥� Weinheimer said. 鈥淗ow do we make it a better, happier place to work? How do we remedy the problems it has and end up with a building that’s a better version of itself? To me, that’s a very exciting design problem.鈥�

External pressure

The primary purpose of a building envelope, according to Lewis, is to protect the interior 鈥� from the air, water, moisture, temperature and security threats. And the Portland Building’s exterior suffers from numerous technical and performances defects.

It will be reconstructed to be weathertight for at least another 50 years. The plan now is to install another building layer 鈥� a rain-screen system. Two layers are far more effective at combating the elements.

鈥淚t’s essentially putting a new facade on the building,鈥� said Todd Miller, a Howard S. Wright project manager. 鈥淭echnology has evolved significantly since the building was built.鈥�

The current proposal is for replacement of painted concrete at the upper levels with a painted aluminum panel system. There’s a chance that historic preservationists, like those serving on the Historic Landmarks Commission, could take issue with the change of materials.

Lewis isn’t worried. He’s accustomed to such mandates as well as alteration restrictions like those of the National Park Service or the Department of the Interior.

鈥淲e’re actually excited because we feel it will improve the look of the building and give it a higher-quality feel than what it has now,鈥� he said.

Performance matters

It’s another misconception, Lewis said, that all parts of the building envelope need to be barriers. Some features, like windows, should function as filters. Switching out the spandrel glass should be barely perceptible outside the building, but felt greatly within because darkness has been a consistent complaint among building occupants.

One major evolution in building envelope construction in the past 40 years has been in prefabrication. Much is now assembled off-site and interlocked on the structure as completed units. This has increased quality control, and reduced labor costs. In the early 1980s, many building portions were assembled piecemeal directly onto the Portland Building.

Soon after Lewis was hired as a consultant (Weinheimer had worked with him on several projects), he read up on the extensive history of the Portland Building envelope’s performance issues, many of which were diagnosed by previous investigators. The systems used in the original construction have required near-constant maintenance to preserve weathertightness.

鈥淟ooking back, we’ve learned a lot about how buildings perform,鈥� he said. 鈥淎nd building enclosure construction has changed a lot over the last 30 to 40 years. We’re a lot better able to predict problems that turn up now. We have options now we didn’t previously.鈥�

The primary origin of moisture has been the joints between the Portland Building’s windows and concrete walls. Water soaking into the tile systems has led to efflorescence 鈥� chalky white stains on the concrete, visible on the exterior.

The other source of moisture has been condensation 鈥� a bigger issue in the moist Pacific Northwest than elsewhere. This happens more frequently in the winter, when the concrete is cold and temperatures drop below the dew point at night.

City officials say employees who work in the Portland Building rarely see evidence of the leaky skin, though mold is a problem.

鈥淭he extent to which that has been occurring we won’t know until those interior finishes are removed,鈥� Lewis said.

Lewis thinks the issues with the Portland Building have more to do with budget constraints at the time of construction than with Graves’ design.

鈥淚t’s not the fault of anyone or any one thing; it’s a function of how the different systems came together, and some of their inherent weaknesses,鈥� he said. 鈥淚 see problems in buildings of all ages, but more (younger than) 50 years than older than 50 years, primarily because of the diversification of systems and architecture. It’s a function of history, culture, explosive growth and construction.鈥�

Weinheimer said the opportunity to enrich a Graves building is a career highlight, despite the Portland Building’s sorry reputation among some local architects.

鈥淚 will say this: I am not a Portland architect,鈥� she said. 鈥淚 was trained on the East Coast, and I was in grad school when this was built and Michael Graves and postmodernism was in the air. There are many people, not just art historians, who believe this is a very important and cool building.鈥�

Portland Building reconstruction

Architect: DLR Group

Contractor: Howard S. Wright

Structural engineer: KPFF

Mechanical engineer: PAE

Electrical engineer: PAE

Cost: $195 million

Scheduled completion: January 2020