There is, of course, another fast-food chain that is known for its coffee: McDonald’s. The company has embarked on a project to make all of its coffee sustainable by 2020 by innovating at every level of its supply chain — investing in its farmers, for instance, as many of the much smaller high-end coffee companies do. (Coffee sold at McDonald’s restaurants in Europe already meets the company’s sustainability standards.)

The scale of McDonald’s business is vastly different from Locol’s, but the consumer experience isn’t, not when it comes to coffee: Both offer a cup that is cheap and approachable.

The efficiencies of the fast-food model are what allow Mr. Konecny to buy high-quality beans for about three times the price of commodity coffee and still sell it for $1. The coffee comes from Red Fox Coffee Merchants, a boutique importer that supplies some of the country’s most exacting roasters; Mr. Konecny coordinates closely with their buyer, who in turn works with farmers to finance them and determine best practices for growing the beans.

The coffee is brewed by Locol’s kitchen staff, and when a new batch is prepared the old batch is cooled and mixed in with cold-brew coffee to be served on ice: There is no waste. Black coffee is easy to scale up; stand-alone coffee shops, with their intricate menus (cortados, almond milk lattes, iced matcha spritzers) can’t compete.

“You couldn’t run a coffee shop selling coffee for a dollar,” Mr. Konecny said. “It wouldn’t be a sustainable business.”

Jonathan Rubinstein, an owner of Joe, a coffee chain based in New York with 14 locations, agrees that the numbers would not work. Joe’s shops are in some of the most expensive neighborhoods in Manhattan, including Greenwich Village and the Upper East Side. Next month, a Joe will open in the World Trade Center. Mr. Rubinstein pays as much as $25,000 per month in rent — he estimates that the average is $15,000 per month — along with labor, materials, utilities, insurance and the many other expenses that are the cost of doing business.