I came across this sign on Saturday afternoon. That’s the first usage of “gender neutral” I’ve ever seen at a restroom. (There ought to be a hyphen, but never mind.) I wondered whether it’s an up-and-coming usage to replace “unisex” or merely is supplementing it.

The gender-neutral restrooms  — one of three options, along with standard gendered rooms — were at El Centro, a satellite campus of Northeastern Illinois University that was completed only last year. It was one of the schools we visited as participants on the Chicago Architecture Foundation’s Schools by Bus tour. Unlike the Churches by Bus tour last fall, only one bus was enough for everyone. As the docents explained, this was the first tour of its kind by the CAF, compared with the churches tour, which has been going on for 20 years.

The schools were interesting, but the churches were more beautiful. There’s no escaping the utilitarian nature of a school, even if the overall design is good. Still, El Centro was well worth a look. The glass structure’s covered with fins: blue on one side, yellow on the other. Stand at one spot and it’s yellow.

Move, and it starts a transition to blue.

Then it’s blue. Or move the opposite way, and it goes from blue to yellow.

Just as remarkably, the building manages to work well despite standing hard by the always-busy Kennedy Expressway.

Last fall, Tribune architecture critic Blair Kamin wrote that, “Chicago architect Juan Moreno, a Colombian native who in 2011 won attention for a striking charter school built for the United Neighborhood Organization in Chicago’s Gage Park neighborhood, wisely saw the Kennedy as an opportunity, not a monster.

“Instead of setting his three-story, steel-framed building far back from the highway and sticking a parking lot in between, Moreno slid El Centro almost alongside the road. Rather than turning out an ordinary box, he bent his long, linear structure like a boomerang to turn its southern end toward drop-dead views of the downtown skyline. Then he sculpted its exterior for reasons both formal and functional…

“In the crucial move, 20-inch-wide fins — their faces blue to the south, yellow to the north — are layered atop El Centro’s glass skin, ostensibly to shield the building from the sun’s glare. But there’s no denying that the fins endow the building with visual rhythms that express the highway’s rushing motion and reveal the influence of the Pritzker Prize-winning London architect Zaha Hadid.”