An architect’s rendition of what a mixed-use development might look like atop a Silver Line Metro station in the middle of the Dulles Toll Road. (Davis Carter Scott Ltd.)

The idea of developers building large buildings on top of the new Silver Line Metro stations along the Dulles Toll Road  — glassy condos, high-rent offices, rotating restaurants — would fit most everyone’s desire for smart growth near mass transit and maybe produce revenue that could be used to keep the tolls down that are being used to finance the Silver Line.

But should the planning for the “air rights” over the stations, and building  the foundations of such projects, begin now, as plans are being made to start building the Phase 2 stations near Reston Town Center, Herndon and  Innovation Center near Route 28? Some say yes, including Supervisor Pat Herrity (R-Springfield), who is urging his colleagues to seriously study the idea, former Fairfax board chair and Congressman Tom Davis, and Leo Schefer, president of the Washington Airports Task Force.

Others say no, including Supervisor Jeff McKay (D-Lee), the Metropolitan Washington Airports Authority (which owns the land and is building the stations) and even Stewart Schwartz, head of the Coalition for Smarter Growth. They note that the market for such development simply isn’t there right now — there’s too much available land and open office space for developers to spend the money on an expensive, speculative project above a Metro station.

But what about…the future?

Fairfax County Supervisor Patrick Herrity supports exploring the sale of air rights, and full development, over Silver Line Metro stations as a way to keep tolls down on the Dulles Toll Road. (photo courtesy Patrick Herrity)

Herrity has been badgering his colleagues on the Board of Supervisors to simply authorize a $30,000 study of “what’s going to be the marketability and shall we move forward when the time is right.” The decision to actually allow developers to build over the Silver Line stations would be up to MWAA, but Herrity said selling air rights could “bring down the tolls and pay down the debt” of Metro construction.

“I think they missed the boat on Phase 1,” said Davis, now vice-chair of the MWAA board, about the first part of the Silver Line, which runs through Tysons Corner and then along the toll road out to Reston. He said the economic climate is wrong now, “but do you plan for the future? You’ve got to be a little visionary on this.” He said the issue was “something I’m going to try to continue the dialogue” with other MWAA board members.

But building a fabulous mixed-use development atop a Metro station has many tricky questions, Fairfax Board Chairman Sharon Bulova pointed out. If the federal airports authority owns the strip of land where the Metro is being built, who controls the zoning and permitting? And what about the revenues from the air rights, or the leasing, or the taxing?

“Who gets the money, and how would they use the money?” if the rights were sold to a developer, Bulova wondered. Federal law seems to require any proceeds from the airport property go to “airport purposes.” Do the tolls on the toll road qualify? Bulova said

“The bottom line,” Bulova added, “is all parties involved should pay close attention to a design for construction that doesn’t preclude being able to build something that has a public benefit” in the future.

Bulova and McKay, the chair of the Fairfax board’s transportation committee, both said the idea of building the pilings and foundation now would add a large new expense to the project. “What Pat [Herrity] is asking us to do,” McKay said, “is spend untold millions of dollars and make it more expensive than it already is.” He said no developers have indicated any interest in building over the stations so far, and “I don’t think we would want to use additional resources to lay a foundation for something that may be decades away.”

McKay said he had asked county staff to prepare a report for the board’s next transportation committee meeting, next month.

McKay and Chris Paolino, a spokesman for MWAA, both said that construction of the pilings and platform for development above the station could be built later, when the demand arises. “We could come back in 20 years and build then,” Paolino said.

A study done by MWAA’s Office of Engineering in February 2011 concluded that “It is feasible for a deck support to be constructed either during the Metrorail station construction or in the future after the station is constructed.” But it estimated the cost at $34 million per station if done during initial construction, or $60 million if done after the station is operational.

The study also cited a George Mason University economic study which said that only 4.4 million square feet of additional non-residential space was expected to be needed in the Reston Parkway area over the next 20 years, almost all of which “could be satisfied using land with already approved zoning in that area. The risk of over-speculation and over-supply is very real.”

Stewart Schwartz, executive director of the Coalition for Smarter Growth, might have been expected to side with Herrity, for once, on this issue. But Schwartz is also a realist, and he didn’t think the market would sustain such a project in the next 30 years. “There is already an overwhelming supply of land at existing Metro stations in the region,” Schwartz said, “plus Tysons Corner, plus what’s available at the Phase 2 Dulles Rail stations, in addition to all of the non-transit accessible land in places like the Route 28 corridor.” Higher construction costs over a station and possible security concerns also loom, Schwartz said.

But there remain a number of influential folks who feel like economic conditions can change, and that, particularly in the shadow of the Reston Town Center, in the heart of the Dulles tech corridor, a new development at “Reston Station” could definitely work. And they feel there is urgency to act now, before the stations are designed and built without the giant buried caissons needed to support the platform for a major elevated project.

“There’s not much time,” said Leo Schefer, president of the Washington Airports Task Force, “but it isn’t too late. If it is feasible to put the foundations in now, I feel confident in 10 to 15 years, we would indeed see air rights being very effective. Where else would you put offices and a hotel and restaurants so conveniently located between the airport and the federal center? It’s a matter of time before they become marketable.”

Schefer sees the Silver Line as a “21st Century Main Street, with the federal center at one end, an international airport at the other, and multi-modal transportation” running between them. “This just provides more land in the most desirable location.” Schefer said he thought Congress would be amenable to crafting an exception to the airport revenue law to allow air rights-development money to be used either to keep tolls down or pay off Silver Line debt.

Doug Carter, a Tysons Corner architect and longtime Reston resident, has been studying this issue for more than a decade, in part because of his interest in environmentally sound development. Part of Robert Simon’s original concept for Reston was to concentrate population density around a series of mixed-use village centers or plazas, to reduce the need for cars and allow space elsewhere for recreation and nature.

Carter, also a member of the airports task force, studied both the engineering and the economics of building above a station, first at Wiehle Avenue, then at Reston Parkway. He said the cost of the caissons, or pilings, was estimated at $8 million, not $34 million, supporting a platform that would be 1,200 feet long and 300 feet wide. Above the platform would be two levels of parking, then a plaza of different buildings, including 2.5 million square feet of office and retail. He said the ultimate cost would be cheaper than constructing new space on land near the Reston Town Center, and that for a time in the 2000s, MWAA’s board was interested.

Then, “the economics of the times changed,” Carter said. “But we’re not necessarily going to have the same market in the next five to 10 years.” And he acknowledged, “Now the issue is, who’s going to pay for it?”

Carter disagreed with the idea of installing the pilings and platform years down the road. “You need to do it now,” he said, “you don’t get the opportunity to do it at a later date.”

Herrity said the economic issue hasn’t been studied in depth. MWAA’s 2011 study only spent one paragraph of a three-page report on the issue.

“There seem to be a lot of unsupported opinions (on air rights) but I have yet to find any real analysis,” Herrity said. “What we need is a thorough review and analysis. We owe at least that to the businesses and residents in the corridor that will be facing skyrocketing tolls”.

One proposed idea of how a Silver Line Metro station might work with development directly above: two levels of parking, then a main plaza level of shops, restaurants and offices. (Davis Carter Scott Ltd.)