Energy-efficient Tower at PNC Plaza has radical, intriguing details

You don't have to look revolutionary to be revolutionary.

That's the takeaway from a visit to the new 33-story PNC Tower that opened last week Downtown.

Except for that odd-seeming canted roof it adds to the Pittsburgh skyline, there's little that distinguishes the appearance of this bank headquarters building from any number of stylish new skyscrapers that have been built worldwide in the past dozen years or so. Architecturally, it is very much mainstream.

But, behind its metal and glass surfaces, it is a radical pacesetter — by far one of the greenest, most environmentally efficient skyscrapers anywhere.

Rather than a conventional, completely sealed office tower that requires energy-intensive air control 24 hours a day, this building will be ventilated naturally about 40 percent of the time, PNC estimates. It will reduce water usage about 77 percent from a typical structure of its size by capturing rainwater and recycling some of its wastewater on site. It will emphasize the use of daylight in work spaces, reducing electric lighting needs. And it is equipped with slatted blinds that open or close automatically to minimize cooling needs on hot sunny days.

All in all, it should be about 50 percent more energy efficient than comparable conventional skyscrapers.

The tower also gives Pittsburgh some decent bragging rights where “green” buildings are concerned. The Center for Sustainable Landscapes at Phipps Conservatory is a rare building designed to respond to the “living building” challenge that requires that buildings essentially consume no more energy or resources than they can produce. And the Frick Environmental Center, in the last stages of construction in Frick Park, will be extraordinarily “green” in that way, too.

While a huge office tower can't currently be as efficient as these two smaller buildings, the new PNC Tower does qualify for a “LEED-Platinum” rating that gives it impressively high marks for energy efficiency. (“LEED” stands for Leadership in Energy and Environmental Design in a program administered by the U.S. Green Building Council.)

Much of this design work is still experimental in use, and it will take some time to know for sure just how well this building will perform.

It will very likely also take time for the 2,200 workers moving in between now and January to adjust to their new $400 million headquarters. Some changes in habits and styles of dress may well be necessary in such a radically different structure.

The building is definitely going to create changes in how workers talk about and use their quarters. It is full of special interior spaces like “neighborhoods” and “inner circles.” There's even a “park” 28 stories up — things we've never seen in Downtown office buildings before. There are “poppers” — which open to let air in — and “floppers,” which let air out into the two “solar chimneys” that run top to bottom through the building and evacuate hot air through its roof.

The tower is elegant and well-detailed throughout. The tall, curved glass facade of the entrance lobby facing Wood Street makes that space bright and expansive. When you look out from it, you see a rich panorama of the variety of other buildings facing it — a collection of big, modern buildings and recently restored small, ornate old ones. Unfortunately, the lobby's glass walls do not extend very far around Fifth or Forbes, which orphans those two avenues as far as the most pleasing ground-level experience of this building goes.

This is the first tall building to go up in Pittsburgh in over 20 years, so a lot of its features, though often seen elsewhere, are totally new here. The 28th floor “park” — a beautiful five-story-high, glass-walled meeting and sitting solarium — has a spectacular presence. Its views from on high encompass Market Square, our three rivers and the hills beyond. This is on a floor where meetings with clients will be held.

Employees will get a respite from their routine when they go to local “neighborhoods,” which are two-story high, glass-walled lobbies, or lounges, depending on how you want to characterize them, that look out over the same view as “the park.” They service each of the office floors in the building, two stories at a time, and offer spaces for individual use, as well as for informal group meetings.

Every floor also has an “inner circle” — a small glass-walled circular conference room available for private meetings.

One key environmental feature of the building is its double glass walls. There's just enough room to walk in the spaces between these walls, and they can, at times, be entered by employees — maybe, one PNC official suggested, for a private telephone conversation or two.

All in all, the Tower at PNC Plaza, as it is officially called, will be a striking addition to the skyline and a welcome presence when you encounter it on foot.

The building was designed for PNC by Gensler, a San Francisco-based firm that is a prominent designer of high-rise office buildings worldwide.

John Conti writes about architecture for Trib Total Media.