PORTLAND, Ore. â€” Urban gardening used to seem subversive. People planted tomatoes in public parks, strung their hops to rooftops to make homebrew and reclaimed empty lots as community farms, never mind the property owner.
Yet here in one of the more thoroughly tilled cities in America, subversive has come full circle: the federal government plans to plant its own bold garden directly above a downtown plaza. As part of a $133 million renovation, the General Services Administration is planning to cultivate â€œvegetated finsâ€ that will grow more than 200 feet high on the western facade of the main federal building here, a vertical garden that changes with the seasons and nurtures plants that yield energy savings.
â€œThey will bloom in the spring and summer when you want the shade, and then they will go away in the winter when you want to let the light in,â€ said Bob Peck, commissioner of public buildings for the G.S.A. â€œDonâ€™t ask me how you get them irrigated.â€
Rainwater, captured on the roof, and perhaps even â€œgray waterâ€ recycled from the interior plumbing are both possibilities, the architects say. But they concede that they are still figuring out some of the finer points of renovating the Edith Green-Wendell Wyatt Federal Building, which was completed in 1975 and is currently 18 stories of concrete, glass and minimal inspiration.
Who will prune the facade? Maybe the same folks who wash skyscraper windows, the architects say. Perhaps the exterior concrete panels removed in the renovation could be reused as salmon habitat in a nearby river.
The G.S.A. says the building will use 60 percent to 65 percent less energy than comparable buildings and estimates a savings of $280,000 annually in energy costs. Solar panels could provide up to 15 percent of the buildingâ€™s power needs. The use of rainwater and low-flow plumbing fixtures will reduce potable water consumption by 68 percent. And energy for lighting will be halved.
â€œIt will be one of the more energy-efficient high-rises in America, possibly in the world,â€ said James Cutler, whose architecture firm, Cutler Anderson, led the design work.
The building has long been in line for renovation and improvements in energy efficiency, but money did not come through until the passage of the federal stimulus package last year, with its emphasis on environmentally friendly projects. That intensified the environmental ambitions; the building, the largest federal stimulus project in Oregon, is being renovated under the G.S.Aâ€™s new Office of Federal High-Performance Green Buildings.
Not everyone is enthusiastic about the plan. In December, Senators John McCain of Arizona and Tom Coburn of Oklahoma, both Republicans, criticized the cost of the project and ranked it second on a list of what they called the 100 worst stimulus-financed projects. The G.S.A. has said that report relied on incomplete data, but the projectâ€™s cost has also raised eyebrows here.
Joe Vaughan, a longtime commercial real estate broker here, said that the buildingâ€™s office space would ultimately cost more per square foot than some other environmentally-conscious projects that are built new.
â€œAs a taxpayer, I think itâ€™s a horrible waste of money that no private developer would undertake,â€ Mr. Vaughan said.
G.S.A. officials said the cost of constructing federal office buildings cannot be compared to private buildings because of security and other government requirements. Nor, they said, should the construction costs of the building be viewed in isolation.
â€œThe idea is that the cost savings are in the energy efficiency,â€ said Caren Auchman, a spokeswoman for the G.S.A.
There are questions about whether the efficiency efforts will work as designed. â€œMost of what we put in our buildings is tried and true,â€ said Mr. Peck, of the G.S.A. â€œOn some part of it, weâ€™re prepared to be a beta tester.â€
â€œMy dream,â€ Mr. Peck added, â€œis we will find a technology that needs a test and we will make the market for it.â€
The renovation is scheduled to be completed by 2013, said Donald Eggleston, the president of SERA Architects, which is overseeing the project for the G.S.A. This summer, he said, landscaping experts will experiment with vines and cover plants that can endure Portlandâ€™s wet, mild winters and its dry, hot summers â€” and do so at varying heights.
â€œWe may train them on some vines in the nursery,â€ Mr. Eggleston said. â€œAbout 50 percent of the windows we need to shade every summer. You canâ€™t take little seedlings up there in Year 1, because you wonâ€™t have anything up there for five years.â€
Love this rendering of a folded green wall by SERA Architects.