The planned sale of Metro’s hulking downtown headquarters could be a game-changer for Penn Quarter. As the agency’s rezoning request for the property heads to a public hearing in two weeks, residents and officials have started imagining what the space may become and how it could change the area.

For many, the preference is clear: Demolish the boring beige concrete building that has housed Metro for 50 years and build something new and exciting. Even Metro, in its application to the D.C. Zoning Commission, argued that making dramatic changes in the space between the Gallery Place and Judiciary Square stations would offer an opportunity to correct “poorly conceived midcentury planning and design principles.”

“The potential for the building is obviously tremendous,” said Randy Boe, executive vice president and general counsel of Monumental Sports and Entertainment, which owns the neighboring arena.

The Jackson Graham Building, at Sixth and F streets NW, opened in 1974 — two years before the Metro subway system opened. The property itself was already owned by Metro because it had been used as a staging ground for construction on the downtown Red Line stations, according to Zachary M. Schrag, a history professor at George Mason University.

When construction was finished and the lot was covered, Metro decided to build its mother ship on the same piece of land. The choice came at the behest of city planners and leaders who saw the decision to build an enduring and respected office building in the center of the city as a heartening first step toward reviving the District’s depleted downtown in the aftermath of the 1968 riots.

“When you’re redeveloping an area, you’ve got to have pioneers, and I think WMATA (Washington Metropolitan Area Transit Authority) was one of its own pioneers at the time,” Schrag said. “The Metro system was designed in part to make that downtown real estate more attractive, so the WMATA building itself was part of the vision it was trying to promote in that part of the city.”

Now, nearly half a century later, the building is woefully outdated; it doesn’t meet fire code or requirements of the Americans With Disabilities Act.

More than a decade ago, then-D.C. Mayor Anthony A. Williams pushed Metro to sell the building and move to a new complex on a five-acre lot near the Anacostia Metro station. His proposal was ultimately abandoned.

Instead, Metro announced in July that it would move out of the Jackson Graham building, find a smaller office space in the heart of the District with easy access to multiple subway lines — ideally, within a few blocks of Gallery Place, Metro Center or L’Enfant Plaza — and send some employees to soon-to-be-acquired offices in Maryland and Virginia.

With more people wanting to work and live downtown, Metro’s property is considered a prime spot.

“It’s a very beautiful area,” said Jack Evans, the Metro board chairman who also represents the neighborhood as a D.C. Council member. “I imagine there would be a lot of appeal.”

There will be significant challenges for any developer who scoops up the property and 43,000-square-foot lot. The Red Line tunnel runs diagonally underneath the building. The sale terms would require the new owner to preserve or move the three huge chillers on the roof of the building that are used to pump in cool air to neighboring stations. The new owner also would need to preserve existing perimeter air shafts, roof antennae and staff entrances into the tunnel.

“It’s more complicated than just going over and tearing the building down,” Evans said.

Additionally, the tunnel leaves little space for underground parking, which would limit the property’s value for some would-be developers.

Even so, potential uses for the property are plentiful. Evans has one idea: a huge event space. Maybe even an extension of Capital One Arena that could straddle Sixth Street with traffic passing underneath, similar to the Walter E. Washington Convention Center.

“We don’t want to be in the position of saying 20 years from now, ‘God, I wish we could have used this for the arena,’ ” Evans said.

Boe, of Monumental Sports and Entertainment, appeared interested in some kind of relationship between the two buildings.

“We would certainly want to consider a potential annex for the arena in the WMATA building,” Boe said. “It’s not hard to imagine a great space for sports, entertainment spaces to watch games, creative concessions or restaurants. We think this space could be used to really expand entertainment options right in the heart of D.C.”

Other options will be possible if Metro succeeds in getting the property rezoned. According to an application filed earlier this year, Metro is seeking to rezone it to a category that would allow greater flexibility for a mixed-use residential and commercial space and would expand the maximum height of the building to 120 feet from 90. The application also requests that the property be subject to inclusionary zoning, which means that a share of any residential construction on the property would be set aside as affordable housing.

The rezoning decision will likely factor into how much money Metro could make from the sale.

In a 2016 assessment, it was determined that the sale value of the building would be $56.2 million to $80 million if it needed to remain as-is, but it could be worth up to $132 million if the property is rezoned and the building demolished.

In documents filed with the Zoning Commission, Metro argues that an aggressive rebuilding project would be the most beneficial option for the community, too.

“As a result of the application of poorly conceived midcentury planning and design principles, the existing [building] detracts from the quality of the public space along adjacent streets,” Metro wrote.

The opportunity for a do-over, they argued, would be valuable to the building’s neighbors.

There are the defenders of the existing building. Among them, Schrag, the historian, who said its humdrum geometric facade serves as an important, and effective, backdrop to “the jewel of Judiciary Square” across the street: D.C.’s 131-year-old Pension Building, an ornate red brick Italian Renaissance Revival structure that is now the National Building Museum.

Metro’s headquarters works perfectly, he said, because it’s so visually unassuming in comparison with its more ornate neighbor.

Still, he says, he’s skeptical that there’s enough loyalty to Metro’s headquarters to save it from being transformed into yet another of the 21st century steel-and-glass edifices that have become ubiquitous downtown.

“Historic preservationists can make a case for anything, but one does need to pick one’s battles,” Schrag said. “Something that is successful at a rather modest mission may not end up being the most important thing to preserve.”