Ten years and a pair of preschoolers into their New Brighton starter home, Jaci and Scott Schloesser decided they were ready to make the big jump.

They had the money for a bigger place, and last May they abandoned the suburbs and moved into a St. Paul home full of traditional character, minutes from brewpubs, bookstores and trendy chefs. “We just love it here,” Jaci said.

The Schloessers’ move reversed the traditional version of the American dream, in which upwardly mobile families flee the city for the cul-de-sacs of the suburbs. But there are growing signs that the path from suburban to urban is one more and more young couples are preparing to follow — with immense consequences for both cities and suburbs.

“Suburbs were conceived, created and built for families,” said Leigh Gallagher, author of a new book called “The End of the Suburbs.” “That was true in the ‘Leave it to Beaver’ era of the ’50s, and it was true in the McMansion era in 2000. The one thing that was consistent was, ‘This is where we go to have a family.’ ”

“For that now to change is threatening suburban communities in a big way.”

Between 2011 and 2012, the number of households in Minneapolis and St. Paul with school-aged children is estimated to have shot up by nearly 7,000, as the number with seniors was dropping by close to 4,000, said research analyst Jane Tigan of St. Paul’s Wilder Research, an arm of the Amherst H. Wilder Foundation that studies social, cultural and economic trends affecting poor and disadvantaged Minnesotans.

In the suburbs, meanwhile, Tigan reported, the number with seniors rose by nearly 15,000, as those with children flatlined — part of a massive demographic role reversal.

New year-end data from the Builders Association of the Twin Cities suggest that for the second straight year, residential construction in Minneapolis towered over that of any Twin Cities suburb — something that hasn’t happened in decades.

School turmoil

The shift in age groups is visible from stores to playgrounds to classrooms to hospitals.

Some suburban school districts, where parents were upended in the housing collapse, have seen turmoil in classrooms.

“Education is getting hammered,” said Darin Hahn, principal of Cedar Creek Community School in St. Francis, in northern Anoka County. “We were close to 1,100 students, and now it’s 800. During the worst of the housing bust, we would have a net loss some years of 70 students in just our building.”

If the problem were just a short-term crisis, he added, it would be one thing. But there are signs it runs deeper than that. “There just seems to be fewer kids in Anoka County than 10 years ago. … It always used to be, ‘there are always more coming,’ and that isn’t happening.”

According to U.S. census data, the number of preschoolers in Anoka County has sunk back to where it was in 1990, almost a quarter century ago, after decades in which that number tripled and quadrupled. Anoka County cities dominate the list of metro suburbs whose average household size has taken the biggest hit since 1990, a sign that empty nests are proliferating.

At the southern end of the suburbs, meanwhile, births in Dakota County have dropped by roughly 1,000 a year since 2006. A leading demographer has warned Lakeville that with kindergarten classes shrinking, the city is stepping into a “future very different from the recent past.”

In contrast, Minneapolis expects thousands of new students to join its schools in the next few years and is spending big to prepare. The latest U.S. census estimates detect a strong uptick in St. Paul as well.

Ann Forsyth, a professor of urban planning at Harvard after a stint at the University of Minnesota, said that aging suburban populations with many childless households are part of worldwide phenomenon seen everywhere but Africa. “In about 15 years, 46 percent of France’s households will be one person, and aging has a lot to do with that,” she said.

But Gallagher maintains there is a major turning away from the suburbs by young adults who grew up there.

“Millennials grew up the back seat of a car,” she said, “and they don’t want that today.”

Trading places

That indeed was a big issue for the Schloessers, Jaci Schloesser said. She’s from Cambridge, he’s from Eagan, and New Brighton was a series of trips in the car.

In St. Paul, “I’m walking distance to the library, the post office, to the convenience markets with every kind of food we would need … and there are restaurants I can walk to,” she said. “In the burbs we had to drive wherever we wanted to go.”

The changing racial makeup of suburban and city schools also suggests there’s a trading of places.

Minority and immigrant students have replaced tens of thousands of white students who’ve aged out of suburban schools over roughly the past decade. Minneapolis schools are becoming increasingly white, grade by grade, with the youngest children reaching 50-50 parity.

Young immigrant parents, having started oftentimes in grim inner-city surroundings, are delighted to find themselves in spots like Apple Valley.

“I did not feel safe in St. Paul,” said Rosario Ayala, a single mom whose Mexican immigrant family started out near University Avenue. “I’m no racist, but you’d hear gunshots.

“Compared to that, it’s perfect in Apple Valley. I can jump on Cedar for a quick trip to Nickelodeon for New Year’s Eve with my daughter, and in summer, walk to the Minnesota Zoo.”

Even with a big move by immigrants, however, suburbs are rapidly aging.

Eagan, so recently teeming with kids, has now suddenly reached the point, census estimates say, where it has more single-person households than married couples with children.

Suburbs such as Lino Lakes and Mahtomedi are seeing jumps in their median age more pronounced than towns in rural Minnesota that one thinks of as completely abandoned by young people.

‘Not a decline’

To counter the trend, many suburbs are seeking to create walkable downtowns and changing their restrictions to allow for things like brewpubs. But they’re also adjusting to the root fact that their age structure is changing.

Golden Valley, with some of the metro area’s oldest neighborhoods, is regearing its parks this year, said parks and recreation chief Rick Birno. It’s adding fitness equipment in parks on a trial basis for adults out on walks, and it’s starting lawn bowling leagues at the golf course.

At a single corner in Edina, just down the road from a hospital spending millions to expand its capacity for heart attack and stroke patients, a Montessori school has closed and a hearing-aid store has opened.

Beside it, there’s a “fitness after 50” mini-gym for those who would shrink from the “loud blaring music and the Spandex muscle shirts of the big conventional health clubs,” in the words of Welcyon CEO Suzy ­Boerboom.

Becky Kidd, a club member working out there last week, said her own little neighborhood nearby is remaining fairly child-heavy, as young families drawn to Edina schools come in and tear down smaller, older homes and put bigger ones in their place.

And Boerboom stressed that the sight of boomers in their 50s and 60s on exercise machines is a sign that aging needn’t be seen as decline.

“This generation is not going to be that of, ‘let’s visit Grandma and Grandpa as they sit around all day.’ It’s a group that wants to ski with them and run with them. It’s a change, not a decline.”