With the FBI planning to move out of the J. Edgar Hoover building on Pennsylvania Avenue, the possibility of restoring D Street so it runs all the way to Pennsylvania Avenue has come up. But it’s unclear whether or not that’d be a good idea, or even if it’d actually be doable.

D Street currently ends when it reaches the FBI building at 9th Street. Image from Google Maps.

In DC, each city block is called a square, and each has a number. Square 1, the block between 26th, 27th, Virginia and K Street NW, is the westernmost square in the L’Enfant City, and the numbers continue to to the east. D Street used to extend all the way to Pennsylvania Avenue, creating the two squares where the FBI building now sits— 378 and 379— as well as a small triangle north of the Avenue where the Ben Franklin statue originally stood.

In the 20th century, D Street was closed, square 348 was enlarged, and squares 378 and 379 merged.

Plat map of the FBI HQ site in 1932

Undoing this would reconnect the street grid, extending a road that goes all the way to Oklahoma Avenue NE in Rosedale. That would make getting around easier for everyone, add redundancy to the road network, and add new space for storefronts that could bring added life to the area. But it would also come at the cost of greater density.

A connected grid is nice, but at what cost?

Restoring D Street would obviously mean less space for buildings. More specifically, it’d be the equivalent of removing a building 60 feet wide, 530 feet long and 160 feet high— and it would do so in the core of the city.

Another way to view the possibility: a loss of nearly $7 million per story, as Loopnet reports the average price of office space in DC at $217 per square foot at the time of print.

It’s not clear how much having D Street run through would help cut down travel times. For those traveling between 10th and D, or between Pennsylvania Ave and D, it would create a slightly shorter route, trimming a couple hundred feet from a trip. But we don’t know that the change would noticeably reduce congestion. Perhaps a traffic analysis could shed light on the actual impact.

The District won’t be the one to decide what happens

In the end, whether or not D Street opens back up isn’t even DC’s decision.

The National Capital Planning Commission (NCPC) will, with GSA and NPS, be developing the new square guidelines that will then have to be approved by Congress accepted by GSA. NCPC is considering reducing the current 75 foot setback from Pennsylvania. If it were to stay at 75 feet, it would be difficult to open D street without limiting square 379 to a plaza. If the set back were reduced to something closer to the property line, which is 25 feet from Pennsylvania Avenue, the block would be large enough to open up D and still build a commercially viable building on square 379.

The NCPC usually leans toward reopening streets from the L’Enfant Plan, which is viewed as a national landmark. But it’s in the federal government’s interest to restore the setback and keep D Street closed, because a closed D Street and smaller sidewalk would result in the highest sales price.

If the federal government does sell the property, will the buyer want assurance that D Street will remain closed? It is entirely within the federal government’s power to simply make it illegal for DC to reopen D Street.

Perhaps a more palatable alternative would be for D street to pass underneath whatever replaces the FBI headquarters, similar to the way M Street goes underneath the Convention Center. This would undoubtedly reduce the value of retail along D, but would retain much of the building space while providing the transportation benefits of a restored D. The current courtyard could even be retained as a gap above D Street.

It would be hard to make an argument that Pennsylvania Avenue needs another plaza, but easy to assert that downtown needs more residential and commercial space. A restored D street, with air rights given in exchange for an affordable housing set aside might be able to address all the competing needs.