United Airlines is building an enormous lounge at Dulles — rivaling Delta's giant New York lounge

United Airlines (UAL0.00%) is making a major investment to build out the experience of its its high-end flyers. As part of a renovation to its terminal at Washington Dulles International Airport, the company announced Tuesday that it would be expanding its United Club passenger lounge there to a whopping 40,000 square feet — a number that is sure to raise eyebrows at rival Delta Air Lines (DAL0.00%).

“This will be one of the largest United Club locations in the network and will subsequently increase the United Club square footage space at Dulles by 70%,” United said in a news release accompanying the announcement.

Not everyone flying United gets to take advantage of the perk. Access to United Club locations is restricted to business- and first-class flyers, as well as members of United’s MileagePlus loyalty program who have logged significant seat time with the company. The combination of free wi-fi, food, and seating that’s more comfortable than typical terminal fare makes access to the lounges a premium benefit that people will spend lots of money to attain.

Airlines on the lower end of the market, like Southwest Airlines and now-bankrupt Spirit Airlines, have been struggling during a capacity crisis that has pushed airfares lower. But United believes it has already turned the corner on that and, like its higher-end rival Delta, is focusing on big-spending passengers in order to drive revenue growth. (Delta just opened its own largest lounge, a 39,000-square-foot Delta One outpost at John F. Kennedy Airport.)

Here’s how chief financial officer Michael Leskinen framed his discussions about the subject with chief commercial officer Andrew Nocella at an investment conference in September:

“Andrew and I talk about investing in food,” Leskinen said. “And look, nobody cares about the food. Our customers care about the food. Investing in clubs. Our customers incredibly care about the clubs. Seats internationally. The customers care about that a lot. And so, we are going to continue to widen the moat by thoughtfully investing in the business.”