All over America, many boomer-age parents are fretting. To fund their retirement, they must sell the big family house. But downsizing is impossible if one or more grown children have moved back home.

“The phenomenon of ‘boomerang kids’ has really upset lots of older folks who can’t roll with their plans because Junior has reclaimed the room he last inhabited in high school,” says John Rygiol, a real estate broker who specializes in the sale of upper-end property.

The migration of kids back to their parents’ property isn’t new in U.S. history. But it last became obvious to demographers during the recession that began around 2008. This was expected to be a temporary response to economic pressures, according to Frank Furstenberg Jr., a professor emeritus of sociology at the University of Pennsylvania.

But the trend has been anything but short-lived. According to U.S. Census Bureau data, more than 20 million young adults currently live in their parents’ home.

“People in the U.S. are marrying later, so the passage to adulthood is longer. But by age 25 to 29, there’s a huge dropoff in the number of young adults still living at home,” according to Furstenberg, whose research focuses on the changing nature of early adulthood.

Here are a few pointers for would-be home sellers with boomerang kids at home:

-- Don’t waver from your downsizing dreams.

Rygiol, who owns an independent real estate brokerage, says he’s witnessed many clients sacrificing their retirement security to maintain quarters for grown children.

“These kids are eating their parents’ lunch. Mom and dad shouldn’t have to sacrifice their retirement plans for the kids,” he says.

Of course, many young adults living in the family home are unaware of their parents’ financial situation. Nor do they grasp the full cost of owning and maintaining the family home. That’s why Rygiol suggests that an important first step toward your housing transition could involve a family meeting to outline these realities.

“Sit down at the kitchen table and explain the whole situation to your kids. Outline all your expenses for the big house and why you need to move to economize,” he says.

Once young adults realize how important it is for their parents to downsize and reduce costs, they’re more motivated to find their own housing solutions, says Rygiol, who’s affiliated with the National Association of Exclusive Buyer Agents (naeba.org).

-- Ponder the idea of a temporary rent subsidy.

Given how hard it is for many young adults to obtain a well-paying job, it can be a jarring transition if they’re jettisoned from the family home without sufficient funds to cover their own housing.

Should you help them pay to rent a place of their own? Rygiol says that might be a realistic way to proceed with your home sale without fear that your offspring could become homeless.

“If you can afford it, give the kids the equivalent of six months' worth of rent for a modest apartment, plus the money to cover the security deposit,” he says.

-- Stay focused on protecting your retirement assets.

Many parents go to great lengths to provide every possible advantage for their children from birth through their college years. They expend hard-earned money for fancy birthday parties, music lessons, sports equipment and academic tutors. Some parents even cover the costs for their kids to study or travel overseas.

But by the time parents reach their late 50s or early 60s, many need to focus much more intensely on their own finances rather than on subsidizing their grown children.

“At a certain stage, people must get on with their own lives,” says Donna Goings, a veteran real estate broker affiliated with the Council of Residential Specialists (crs.com).

If you have a grown child or two living with you yet you need to downsize, it might be feasible for your offspring to remain in your next household for a short while, assuming you’ll have a spare bedroom there. But in that case, Goings says you should charge them at least a minimal level of rent, proportional to what income they can bring in.

Should you feel guilty about asserting your own need to downsize, even if that means your boomerang kids can’t go with you to the new place and must find alternative housing? Not at all, Goings says.

“The best thing you can do for your kids is to see that they get on their own two feet so they’ll develop the skills for independence,” she says.

(To contact Ellen James Martin, email her at ellenjamesmartin@gmail.com.)

After her father gave her $20,000 toward a down payment, a professional writer of 28 was emboldened to buy her first home. Seizing the opportunity before prices rose further, she called a real estate agent and hastily arranged to tour property in a popular area.

Within hours, she’d signed a contract to buy a small one-level contemporary on a wooded cul-de-sac. But the property was a mismatch for the lifestyle of a single woman seeking an active social life. As it turned out, nearly all her neighbors were young families.

“It was crazy for this young lady to pick such a child-friendly neighborhood when her top priority was really to date and hang out with friends her age,” says Merrill Ottwein, a longtime real estate broker and past president of the National Association of Exclusive Buyer Agents (naeba.org).

“Far too many buyers see a house in isolation from the rest of their lives,” he says.

Skylar Olsen, a senior economist for Zillow, the real estate data firm, sees signs that an increasing number of buyers in their 20s and early 30s are delaying a purchase until they can afford a place they’d keep for 10 years or longer.

“More millennials are saving up longer and skipping the starter home until they can get a property to meet their needs for years to come,” says Olsen, noting that many buyers in all age groups are now more cautious.

Doro Kiley, a certified life coach who helps clients craft their plans, says that before launching a home search buyers should first imagine their ideal home. That way, they’re more likely to get close to the best possible match.

Here are a few pointers for buyers:

-- Envision your future on paper.

Partners often differ on ideal housing choices. That’s why Kiley says it’s helpful for both to write down their respective visions and then seek to shape them into a single statement.

Written statements help people clarify their thinking and refine the details of their plans, as they move through successive drafts. They’re also a way to help reconcile differing views.

“In my work, all the time I come across husbands and wives who start with different visions,” Kiley says.

-- Carefully ponder the issues around commuting time.

As Ottwein says, one of the most wrenching tradeoffs many families face is between a larger, newer house with a longer commute and a smaller, older place that’s closer to the city center and the workplace of one or both partners.

Homebuyers who consider an outer-tier suburb are often driven by the desire for a larger property or what they perceive to be better schools.

But before you opt for a distant suburb, Ottwein strongly recommends you do morning and afternoon rush-hour test drives. This way, you’ll know more precisely what sort of traffic to expect if you buy there.

Ottwein says buyers should disabuse themselves of the notion that the current level of traffic congestion on their path will remain static. The odds are that the traffic will worsen as the years go on.

-- Don’t automatically assume a large yard is essential for kids.

Many people with young children hang on tightly to the hope that their offspring will have a large backyard where they can frolic, just as they did as youngsters. This aspiration can influence them to pick an outlying suburb at the expense of their convenience and commuting time.

But are the tradeoffs necessary to acquire a large piece of land worth it? Not necessary, says Ottwein, noting that today’s children often spend much more time in organized athletic and recreational activities than did their parents.

“These days many kids ... have little time for the sort of free backyard play their folks remember so nostalgically from childhood,” he says.

-- Give yourself the comfort of a deliberative home search.

These days, those seeking to own a home in a popular neighborhood can face fierce competition. They feel pressured to act quickly, lest they lose out to a rival. Because of that, many buyers take regrettable shortcuts --often rushing into a purchase without analyzing whether the property they’ve picked truly matches their lifestyle.

But because so much is at stake, Ottwein urges buyers to slow the process down or face the prospect of a taking a wrong turn.

“Some buyers get hyped by a hot market. These are people who want to win at any cost. But you don’t want to look back one day to realize that you’ve won the battle but lost the war,” he says.

(To contact Ellen James Martin, email her at ellenjamesmartin@gmail.com.)

Mortgage rates, though a tad higher than prior to the presidential election, are still hovering near historic lows. And real estate analysts say fears of rising rates are now spurring many seniors into opportunistic housing moves.

“Seniors are very hyperaware of interest rates these days and how they can lock in low housing costs for their retirement years,” says Daren Blomquist, who tracks real estate trends for Attom Data Solutions (attomdata.com).

Blomquist says one increasingly strong trend involves seniors migrating to cheaper areas to reduce their living expenses.

“For example, some older folks are cashing out properties in high-cost San Francisco and moving to less pricey Sacramento. Others are leaving the New York or Washington, D.C., areas for towns in less costly parts of Florida or Arizona,” he says.

Of course, there are many ways for seniors to take advantage of low mortgage rates. Besides downsizing, they could refinance an existing mortgage to reduce their monthly payments by cutting their interest rate or extending the term. Or they could tap their equity through a cash-out refinance which allows them to rehab their place to prepare for their later years.

“People who want to age in place might need to add a first-floor bedroom so they won’t have to use stairs when they get older,” Blomquist says.

Here are a few pointers for seniors considering their real estate options:

-- Begin with a snapshot of your full financial situation.

Thomas J. Casey, a certified financial planner, says many homebuyers of all ages make real estate decisions in isolation, without first considering how their moves fit into an overall financial plan. But he says it’s especially important for seniors to ponder these implications.

“You need a spending plan that tells you how much it now costs you to live and how you expect that to change going forward,” he says.

One obvious way to develop a comprehensive plan is with the help of a financial adviser. If you choose that route, Eric Tyson, co-author of “Personal Finance After 50 for Dummies,” recommends you hire one compensated on a fee-only basis. That means the planner doesn’t receive commissions by selling you stocks, bonds or insurance products. Also, select an adviser who takes a neutral view of real estate.

“Many financial planners are biased against real estate,” he says.

You can find the names of fee-only planners through the National Association of Personal Financial Advisors (napfa.org).

Alternatively, Tyson suggests you consider hiring a certified public accountant to assist you in the planning process. One way to find a CPA who specializes in personal finance is through the American Institute of Certified Public Accountants (aicpa.org).

-- Reduce the cost of doing your own financial planning with some self-analysis.

One key step in financial planning involves an examination of your current spending patterns. You need to know how much you routinely spend -- both in terms of mandatory expenses (like out-of-pocket health care costs) and discretionary outlays (like restaurant bills).

Unless you regularly track these numbers (on paper or with a specialized personal finance tool, such as Quicken), assembling this information can be time-consuming. To avoid paying an adviser to assist with this preliminary work, pull out your credit card statements and checkbook and tabulate these numbers yourself.

“Crunch data before walking into your adviser’s office,” Tyson says. He also recommends you use the free online retirement calculators available through such investment firms as Vanguard (vanguard.com), and Fidelity (fidelity.com).

-- Don’t assume rapid housing appreciation in the future.

Past turmoil in real estate markets has done little to weaken enthusiasm about the investment potential of property, according to Tyson. But he contends that due to high transaction costs, few seniors can expect to make a profit on a home they purchase in 2017 unless they intend to hold the place for at least three to five years.

-- Take into account your favored retirement lifestyle when buying a home.

Through the years, Casey has noticed that his clients vary widely in terms of their expectations for living standards in retirement. Some want to continue dining at expensive restaurants and to travel abroad. But others expect to spend modestly and work part-time as long as possible.

Besides factoring in finances, seniors need to think about where they'll be comfortable living in their retirement years.

“Location is probably the most critical factor," Casey says. In my experience, people who retire near family and friends are much happier than those who move to an isolated place, even if that faraway place is much cheaper.”

(To contact Ellen James Martin, email her at ellenjamesmartin@gmail.com.)