Last week, while the Seattle City Council gave final approval to more street food vendors in public places, Borders Group Inc. began its liquidation of most remaining Borders bookstores, including locations in destination American downtowns.

This is related news, because both items are about how public and private uses and spaces mix in urbanized areas. Both raise questions of "no net loss" of urban, and downtown "third places" and how to make a more livable city.

In my view, despite the today's international focus on urban street food vending, the paradigm left behind by Borders leaves bigger questions for back-to-the city devotees.

Some definitions are in order. "Third place" is a decades-old term championed by sociologist Ray Oldenburg for venues which bring people together in the tradition of the American colonial tavern or general store. The idea remains central to urbanist thinking, and describes those places, other than home or work, where we gather, debate and trade. "No net loss" is a term borrowed from the vocabulary of wetland conservation, and allows for replacement of lost assets with equivalent resources.

"No net loss" is the essence of sustainability.

In the last decade, as forms of home and work evolved, conceptions of third places changed as well—from larger footprint commercial spaces such as Borders, to mid-size bookstores (e.g. Third Place Books), to back-to-the-commons public spaces and the pop-up agora. Street food vending is somewhere in the mix as an expanded place of ambience and employment—and to all but certain bricks and mortar restauranteurs—a likely urban benefit.

In response to the Borders news, some pundits, like Josh Stephens in Planetizen, have called for a better, non-Walmartian reinvention of the bookstore. In his view, big boxes—even when urban— destroy Mom and Pop purveyors. Amazon and Kindle aside, he makes a good case for a new, post-recessionary wave of independent urban bookstore startups. For those bookstores, I hope that he is right.

But as to third places—and I am going to assume that "big books" uses can play such a role—there is something bothersome about the final demise of Borders' urban core locations. While perhaps an opportunity for the independent competitor, what of the potential loss of third place uses in high-value urban downtowns?

Will the prime square footage occupied by Borders have similar, third place potential once reclaimed? Will replacement uses provide the equivalent, fusion business purposes of books, coffee, lecture and song?

Last week, CNN Money was also abuzz with the the re-realized location efficiencies of heading back downtown. In that spirit, let's hope that downtowns retain dedicated uses of value to those soon to arrive.

Both the private market and public policymakers should work together on the potential prize of livability: assuring the sustainable, no net loss of square footage devoted to urban third places.

All images composed by the author.