Tech For Housing, a blog written by Bay Area techies “united in support of more housing in the Bay Area,” proposed a plan on Monday to kill many birds with one stone by funding BART through new housing developments on BART land.

There’s very little chance of BART actually following through on such a suggestion, but it’s not a half bad idea on paper:

BART owns acres of surface parking spread out across the system. If it were to redevelop these parking lots into high density, mixed use developments, it could [...] create a high yield stream of revenue. The entire region needs more housing, so every extra unit of additional housing would help. Concentrating development on top of transit nodes would also mitigate congestion on our roadways. And if BART were able to influence development around its network, it could redirect passenger load in directions where the system has slack capacity.

There are some problems with this idea, chiefly that BART needs those parking lots. A BART spokesperson tells Curbed SF that on weekdays parking at all but two or three stations is full by 8 a.m. (which is hardly news to regular commuters).

[Update: Tech For Housing writer Jeff Andrade-Fong suggests “Consolidating parking in an above ground structure of moving it underground.”]

There are also practical hurdles for a public transit agency suddenly diving into housing development in two dozen cities with different rules, and to getting the public on board with the idea.

Still, the techies aren’t just pulling this idea out of the sky. They have a proof of concept:

The MTRC [Hong Kong’s Metro Transit Railway] has two major revenue streams. The first is its ticket sales [...]. The other is the value generated from its real estate holdings around each of its stations. This is where the MTRC makes the bulk of its money and is how it manages to foot the bill for constant maintenance and reinvestment.

As it turns out, this is true. And Hong Kong’s rail lines are probably the most acclaimed public transit system in the world, running at a profit and investing billions into constant upkeep and a workforce of 5,000 technicians.

In 2016, the Business Times called the MTR model the “gold standard” (though the BT story also warns that there are risks to the system if it stops having room to grow).

In 2015, CNN called MTR “the ironman of world metro systems.”

And the consulting firm McKinsey & Company notes:

This model has become more than a source of railway financing; it is a critical part of Hong Kong’s urban-development approach. Planners and government agencies seek to make every new railway line or extension into a corridor where well-planned, high-quality communities can flourish.

Practical hurdles notwithstanding, it’s hard to dismiss the tantalizing notion of more housing next to transit and more revenue for BART in one punch.

It’s a pipe dream, of course. But then, so was BART itself once.