New York City’s Metropolitan Transportation Authority (MTA) has demonstrated that one of the most novel — and also most sensible — uses for old, decommissioned subway cars is to plop them into the middle of the Atlantic Ocean where they function as artificial reefs and provide shelter to aquatic life.

Washington, D.C.-based architect Arthur Cotton Moore, however, has dreamt up a wholly different idea for the afterlife of defunct subway cars in his city at the same time as the Washington Metro begins to yank the system’s propulsion problem-plagued 1990s-era 4000-series cars from service and retire them. Like the MTA, Moore has repurposing instead of scraping squarely in mind. But why use junked subway cars into crucial habitats for fish when they could also easily be retrofitted to provide housing for terrestrial life, namely the District’s homeless population?

That’s the idea behind a new concept from Moore, first revealed last month in the Washington Post.

Moore, 81, is a D.C. native who has built a lauded career around ambitious, restoration-driven projects around town including revamps of historic — and often endangered — D.C. edifices including Jefferson Building of the Library of Congress, the late-19th century Cairo apartment tower in Dupont Circle (D.C.’s tallest residential building) and the glorious, bell tower-topped Old Post Office Pavilion, a Trump Organization-headed project that Moore withdrew from in 2012 due to health reasons. That iconic building is now the site of a garish, 263-room ethics quagmire otherwise known as Trump International Hotel Washington, D.C.

As CityLab notes, Moore really did write the book on historic urban preservation with 1972’s "The Powers of Preservation: New Life for Historic Urban Places."

While Moore’s vision for reusing old Metro cars is decidedly not as grand in scale as some of his major past works, it’s commendable in its altruism and ingenuity. Moore envisions each single car being divided up into two petite, one-bedroom apartments, each roughly 506 square feet. Each fixed, RV-style unit would be outfitted with prefabricated bathrooms and kitchenettes and topped with solar panels.

“That’s not a bad one-bedroom,” Moore who refers to himself as “kind of a recycler of sorts,” tells the Post. “Small, but still something livable, compared to where they’re living now: under the bridges.”

He adds: “They are a very nice enclosure which is watertight and has lovely windows.”

4000-series Metro car Today's aging subway car, tomorrow's transitional housing unit for the homeless? (Photo: Wikimedia Commons)

Ideally, a whole slew (86 to be exact) of 4000-series Metro cars-turned-transitional housing apartments would be installed in a single site, forming a self-sufficient mini-village of sorts dedicated to D.C. residents for whom safe, secure housing hasn’t been easy to come by. Moore envisions communal vegetable gardens, playgrounds, a medical clinic and a social services center playing into the picture as well. In total, the community could be home to up to 400 people.

However, securing a city-owned vacant parcel in which to establish such a compound is one not-so-tiny issue. Speaking to CityLab, Moore identifies the RFK Stadium site in southeast D.C. as an ideal place to establish such as community — a community that Moore’s wife and business partner, Patricia, describes as giving “our homeless citizens a home, and the dignity, privacy, and safety they deserve."

The Post also notes the presence of asbestos in some retired Metro cars as a potential roadblock.

Metro spokesman Dan Stessel tells Post columnist John Kelly: “Just as we are providing decommissioned rail cars upon request to emergency responders in the region for training purposes, Metro will consider any viable proposal for other uses of the cars, provided that it is budget neutral to Metro and complies with all applicable laws, regulations, etc.”

While the scheme has drawn comparisons to shipping container-based emergency housing, Moore is quick to point out that old subway cars are inherently more habitation-ready and, in turn, less expensive to convert into housing than shipping containers.

He tells CityLab: “With the usual solution of those shipping containers, you would have to cut holes in them, but there are lots of windows already in a waterproof aluminum shell in the Metro cars — there’s a built-in outside view. There could be two units made out of each car, with the connecting doors between train cars repurposed as a front door to a unit. We would add four concrete footings where the wheels would be, welded to a series of anchor bolts. The cars are already heavy and aerodynamic enough that they could withstand strong winds.”

Again, Moore’s decommissioned subway car reuse scheme is just a concept at this stage. However, it isn’t completely without precedent. In 2005, Hawaiian architecture firm International Group 70 headed up an effort to transform mothballed Honolulu city buses into mobile homeless shelters complete with private showers and sleeping areas.

Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.