Jan LaRosa runs her fingertips down the trunk of the large tree in the backyard of her Winnetka home, admiring its size and pondering how long it has been there.

She had hoped that one day her own roots in the North Shore community would grow as deep, but LaRosa is a Winnetkan no longer. The village is now beyond her price range.

When the bank auctions her Willow Road home later this month, she and her family will leave their house, their neighbors, and her favorite tree behind.

The LaRosas are among a growing number of Winnetka families who are being priced out of the community – an example of why affordable housing advocates support a new initiative to diversify housing options.

LaRosa and her husband moved to their modest Winnetka home in 2006, along with two young children they’d adopted from China and who were warmly received in Winnetka, she said.

“Never one time was anything unkind or unloving done to my children here,” LaRosa said during a lengthy debate on the affordable housing proposal before the Village Council on April 12. “We were welcomed with open arms.”

But three years ago the work-hours of LaRosa husband were cut in half after 36 years with the same employer. In March she underwent her third heart surgery. The family has insurance, but it did not cover all the medical costs.

The bank began the foreclosure process on their home in July.

The affordable housing debate continues in Winnetka as the economy continues to sag. And though the North Shore community is often stereotyped as rich and fiscally conservative, it is not immune to foreclosure and the struggle to avoid it.

“Situations like Jan’s are more common than people think,” said Gail Schechter, executive director of the Interfaith Housing Center of the Northern Suburbs. The group is certified with the US Department of Housing and Urban Development to work with homeowners to avoid losing their homes.

LaRosa wasn’t aware of the Housing Center in time for it to help, Schechter said.

“It’s very frustrating,” Schechter said.

But the number of Winnetka residents coming to the Interfaith Housing Center has increased in recent years. In fiscal year 2007-08, 11 Winnetka residents received housing assistance from the organization. That number jumped to 27 by fiscal year 2009-10, according to Jasmine Brewer, the agency’s housing counseling director.

Supporters of an affordable housing plan say the village’s demographics are shrinking — as the housing stock value escalates, it prevents middle class residents from living there.

Many argue that Winnetka is no longer affordable to instrumental people who work there — like teachers, firefighters and police officers.

Of the 216 teachers at Winnetka School District 36, only 11 of them live in Winnetka, according to officials. None of the 27 sworn police officers and none of the fire department’s 25 personnel live in town.

Seniors, too, have a difficult time remaining in the village, statistics indicate.

The village lost 260 rental units — a 37.5 percent decrease — between 1980 and 2000, according to the most recent census statistics, according to a report by the Winnetka Plan Commission conducted along with the University of Illinois at Chicago’s Nathalie P. Voorhees Center.

The village also appears to be a short-term place for families to raise school-age children, but not a prime location for young adults or seniors, statistics from the report show.

That’s why Kathy Johnson and her husband moved to Winnetka 20 years ago — to take advantage of the schools.

In the years since, they have been involved members of the community. They’ve started block clubs, coached youth sports, and volunteered as Cub Scouts and Boy Scouts leaders. Their three sons have attended public schools.

The couple makes a combined $150,000 per year, Johnson said. She works for an area university as a regional director for outreach and public service. Her husband is an economist for the federal government.

“We knew when we came here that it’d be a stretch,” Johnson said.

Their youngest son is scheduled to graduate from New Trier High School this spring, and move on to college. So the couple plans to put their house on the market and move somewhere cheaper. They’re not being foreclosed — they just can’t afford to stay, Johnson said.

“Just the cost of living on the North Shore in pretty much every conceivable way is higher, and we’ve just reached the limit where we can’t do it anymore,” Johnson said.

It wasn’t always like that. She and her husband moved to Winnetka in 1991 from the Rogers Park neighborhood in Chicago. They loved the diversity and sense of community in their old neighborhood, and were eager to become as involved in their new one.

“There were still working class people in Winnetka at that time. And they were my neighbors, 20 years ago,” Johnson said. She recalled neighbors that included a watch maker, a public school teacher, and a federal employee.

“It wasn’t a block of only investment bankers, though there were some,” she said.

One by one, she watched them leave town. Their homes were either torn down and replaced with larger, more expensive ones or significantly expanded.

That’s one trend documented by statistics in the Plan Commission-UIC report. According to village statistics, there were 441 homes in Winnetka torn down and rebuilt from 2000 through 2009.

The “teardown phenomenon,” the report says, “has replaced more affordable single family homes with homes costing twice or even three times as much. The result is a less diverse housing stock composed predominantly of expensive single family homes suitable primarily to large two-parent affluent families with school-age children.”

Johnson said that she and her husband are the kind of people that Winnetka should value.

“We’re highly educated, we’re public servants, we’ve added to the community, and that should be something people think about when they think about an affordable housing plan,” she said.

And though they’ve made scores of friends during their two decades in the village, it’s not much of an option as they look toward the future. They could move into a smaller home, but she notes that they’ve still got two kids who will be coming home from college to visit.

“So a little two-bedroom condo isn’t enough for us, which is probably all we could afford in Winnetka,” Johnson said.

An affordable housing plan might have made it possible for them to remain, she added.

LaRosa, too, hopes the village adopts a plan that might prevent a future family from going through what hers has gone through.

“If it had been there for us, it might have been a soft place to fall,” she said. “It could have helped us.”

But she admits that she doesn’t have a dog in Winnetka’s affordable housing fight.

“Barring a miracle, it’s too late for our family,” LaRosa said.

The four of them have moved into a rental house in Wilmette with their eldest daughter, her husband and their 2-year-old. It’s cramped, but it’s home.

She thinks about April 25 — the day the bank will auction her Winnetka house. She still has a few boxes to pack, and while she’s there, she sometimes takes a break to look out the window and think about the trees in her backyard, whose roots seem so permanent.

“Every day now I sit and look at my big old trees and I wonder if they’ll miss me as much as I’ll miss them,” LaRosa said.