It is well understood that many young adults have yet to leave the nest, a phenomenon that has helped suppress demand for first-time housing. But a new analysis shows just how powerful the stay-at-home trend has been.

According to the most recent Census Bureau figures, one in three young adults ages 18 to 34 lived in their parents' or in-laws' homes in 2012. By comparison, only one in four young adults lived with their parents in the decade between 1990 and 2000.

People in this age cohort typically represent half of all rookie homebuyers, says Natalia Siniavskaia, an economist at the National Association of Home Builders, and their delayed willingness -- or ability -- to strike out on their own has helped drive down the new house market.

The largest shift in living preferences occurred after 2005, especially among those young adults ages 25 to 34. Between 1990 and 2005, the share living with parents was about 12 percent, but it rose to more than 19 percent in 2012.

The younger cohort, ages 18 to 24, is more likely to remain at home, with 57 percent doing so in 2012.

The main reason young adults are declining to leave the family nest is their inability to find suitable employment. And as the unemployment rate grew in the late 2000s, says Siniavskaia, so did the share of young adults who opted to stay home. Indeed, the share of unemployed in the 25-to-34 age bracket doubled, from 7 percent in 2000 to 14 percent in 2012.

And even though the unemployment rate started to decline in most states in 2011, the share of young adults living with parents "remain(s) stubbornly high and has even increased" in some places, the NAHB economist points out.

This, she says, suggests that it takes longer for young adults to overcome the overall sense of economic instability and gain confidence in their own financial independence before moving out of their childhood homes and into places of their own.

You've heard of homeowners who are "underwater," or who owe more on their mortgages than their houses are worth. Now comes a new term -- "under paper" -- for owners who have paid off their loans but can't prove it.

When you pay off your loan, you should receive a piece of paper variously called a mortgage satisfaction, mortgage release or mortgage discharge. The same paper should be sent to your local deed-recording office so it can become part of the public record.

But routine isn't always a matter of course, and the lien on your house remains a paper lien in the public records until it is removed. Worse, this scenario isn't all that unusual, says John McDermott, a real estate attorney in Chelsea, Mich. "It happens all the time."

And when your loan has been sold to another lender, maybe two or three times over, the problem becomes that much more complicated. A lender can't sign off on this important document if it doesn't own the loan or have the authority to sign as an agent of the loan's rightful owner.

The moral: When you pay off your loan, make certain you receive a mortgage satisfaction. You should receive it within 60 days of your final payment. Then, after about 30 days or so, check with your recorders' office to be certain the satisfaction has been recorded.

If you don't, and you subsequently go to sell your house, the deal could be delayed until you prove the house is debt-free. And doing that could mean a lot of extra expense.

It is not surprising that lumber is the most expensive segment of the overall construction costs in building a house. But what's the next most costly feature?

That would be excavating the site. Moving all the dirt around to where the builder wants it, and then putting in the foundation and backfilling the hole, runs nearly 10 percent of the cost to build a typical single-family house, according to the latest breakdown from the National Association of Home Builders.

Together, the cost of the windows, doors, stairs, lighting fixtures, gutters and downspouts don't account for that much, according to the figures from 2011, the latest year for which they are available.

The only cost that even approaches the expense of excavating is plumbing, which accounts for 6 percent of the total. The electrical wiring runs 4.4 percent, which is about the same as the cost of siding (4.7 percent), the heating and air-conditioning system (4.8 percent), drywall (4.4 percent) and tile and carpet (4.5 percent).

It pays to hire a professional to photograph your house when listing it for sale, according to Redfin, a real estate brokerage firm.

This bit of news may be self-serving. After all, Redfin covers the cost of professional photos when you list with the company. But nevertheless, it says that for houses priced from $400,000 to $499,000, those professionally photographed sold for an average of $11,200 more than places shot by an amateur.

Redfin's study of houses listed and sold in 2013 in 22 major markets also found that those shot with a digital single-lens reflex camera sold 21 days faster that those shot with a point-and-shoot camera.

Like many solid real estate agents, Jane Armstrong arrived early for the closing a few weeks ago. And it's a good thing.

The Las Vegas short-sale specialist had time to review the "HUD-1" closing statement before the actual signing, and she discovered several mistakes, including $200 in fees that shouldn't have been charged to her client.

Armstrong, who hangs her shingle with the Signature Real Estate Group, had requested a copy of the completed form in advance -- twice -- all to no avail. Still, she was versed enough in the process that showing up 20 minutes early gave her enough time to spot the errors and get them corrected.

"My client may or may not have caught the mistakes," the Nevada agent says. "But that's my job."

Fortunately for both buyers and sellers, most agents feel the same way. And they show up for signings even when they are not required to, or when the closing is handled by attorneys who represent each side of the transaction.

In some parts of California, for example, buyers and sellers separately sign the stack of papers necessary to transfer ownership, sometimes days apart. But that doesn't stop Terri Vellios of Keller Williams in Campbell, Calif. from being there for her client.

"I've had escrow officers fly through the documents while my clients' eyes glazed over," she says. "Sometimes the escrow officer doesn't explain it to my clients in terms they understand. In those cases, I will explain what something means."

Buyers and sellers also sign independently on the other side of the country in Virginia and "are never at the table together." But Jim Mellen of RE/MAX Peninsula at New Town in Williamsburg always accompanies his buyer clients, and occasionally his sellers.

"Buyers are relying on us. We owe it to them to be there," he says.

Mellen has heard other agents say they don't attend to avoid liability, but that's poppycock as far as he's concerned. "I think that is lame and borders on insubordination. We are licensed professionals and have a responsibility."

Many loan officers don't feel the same way. Their presence at settlement isn't required, either. After all, the closing professional's job is to carry out the lender's instructions. But most agents would prefer that your lender -- in the form of the person who actually took your application and ushered you through to approval -- would take the time to sit alongside you at settlement.

As it is, it's a toss-up whether that happens or not. Sometime loan agents show, sometimes they don't. But if not, they are typically just a phone call away.

Still, realty agents say there's nothing like being there. For example, when loan documents are late or the final numbers do not line up with what was agreed upon previously, the lender can offer an explanation on the spot, says Marty Soller of Coldwell Banker King Thompson in Columbus, Ohio.

"We have had to wait up to four hours for funds to be wired. That can be quite a problem when the buyer's movers are waiting at the house to start moving in," says Soller, who has seen cases where the closing was delayed over the weekend to the following Monday, forcing his client to pay double for moving and storage and find a place to stay.

Most closings go off without a hitch. But any number of bad things can happen, so it helps to have someone on your side who has been with you since the beginning on your house-hunt journey -- someone who understands your situation as thoroughly as you do.

Here's a short list of common things that go wrong at closing.

-- Acrimony. If you've had a particularly arduous negotiation, things can sometimes boil over when you sit down at the table, face-to-face with your adversary. Every agent has a story about this, but Michael Marks of Keller Williams Realty in south Florida takes the prize.

Marks attended a closing where the seller showed up in drag and proclaimed the entire contract a sham, saying that he was entitled to more money. At another of Marks' closings, armed guards were present "because of threats of bodily harm during negotiations."

-- Trouble saying goodbye. Sometimes the seller has a special bond with the house and has a tough time letting go, to the point where he wants to back out at the last minute.

Dee Smith of RE/MAX Premier Group in Wesley Chapel, Fla., once had a client who was so overcome with emotion selling the place she had owned with her recently deceased husband that she had trouble continuing. But Smith "was able to console her and help her through this tough ordeal."

-- Typos. Often, agents find misspelled names, incorrect addresses or wrong apartment numbers and other errors that the buyer and seller missed.

Earl Walker of Keller Williams in Sapphire, N.C., once discovered that the survey didn't include all the property being sold. But he was able to get the mistake corrected. Lenore Wilkas of Coldwell Banker in San Mateo, Calif., has seen wrong loan amounts. Others have seen incorrect interest rates.

-- Problems at walk-through. Sometimes the house isn't clean enough to satisfy the buyer, or perhaps it is discovered that an appliance doesn't work. Sometimes items that were supposed to be taken care of by the seller -- repairing a balky closet door, for example -- were not.

Perri Feldman of Keller Williams in Short Hills, N.J., has seen gaping holes where TV wall brackets once hung. Another KW agent, Kirk Pugh in Wilmington, N.C., was there when the builder switched the range with one of lower quality. Had he not been present, the buyer might have accepted the change without comment. Instead, Pugh was able to insist on an $800 credit on his client's behalf.

-- Missing items. Property that was supposed to stay with the house -- washers and dryers, chandeliers and curtains are the most popular -- are missing at walk-through, and the agent has to mollify his client. "Even rented fixtures like water softeners can result in a 'discussion' at closing if the rental was not disclosed beforehand," says Paul Spoerl of Century 21 First Realty in Appleton, Wis.

-- Junk left behind. Sellers sometimes leave "stuff" they no longer want, thinking that maybe the buyer would want their junk. To save the deal, agents have had to find cleaners in the last minute to get rid of the items the seller should have disposed of in the first place.

Once, a seller left a house almost fully furnished, recalls Noreen Parrell of Better Homes & Gardens Rand Realty in Briarcliff Manor, N.Y. "These things don't happen often," she says. "But when they do, you have to be there."

-- Lack of child care. Agents are sometimes called upon to keep the children occupied so their parents can concentrate on the closing papers. Why people bring their kids to this important legal proceeding is a question for another day. But when they do, agents are often called on to hold the kiddies' hands -- or change their diapers -- while the signing is being completed.

-- Missing documents. More than a few buyers have forgotten to obtain homeowner's insurance or left their driver's license on the coffee table at home. Maybe the seller forgets to bring the keys. Whatever the case, the agent who's there can step in to save the day.

Despite the recent spate of far-reaching federal regulations hammering the mortgage business, innovation is far from dead.

For example, one of the nation's largest credit unions now allows borrowers to reset their rate at no cost up to five times over the life of the loan. A Beverly Hills company has created a way for small investors to put their money in commercial real estate deals that are usually reserved for wealthy individuals. There's also a new online search tool that allows homebuyers to identify and compare houses for sale based on drive times to work and other places, night and day.

The rate protection feature is offered by the Pentagon Federal Credit Union, a 1.2 million-member institution headquartered in Alexandria, Va. It is available on the credit union's 5/5 adjustable rate mortgage, which adjusts to the then-market rate every five years over the 30-year term.

Beginning with the loan's second year, borrowers can choose to change their rate to PenFed's current rate plus 0.25 percent at any time. So, say in the third year, you don't like which way rates are heading and you want to nip an increase in the bud. Or you'd simply like to take advantage of lower rates. You can simply "click" to reset the loan on PenFed's website.

You can exercise the reset option anytime after the first year, up to five different times. But once you do, you have to wait another 12 months to do so again.

The feature gives borrowers five shots at the brass ring, says PenFed executive James Schenck. It "puts borrowers in control of their mortgage," he says, and is a cheaper, less cumbersome way for them to refinance and take advantage of current rates.

The new investment vehicle comes from Realty Mogul, which calls it "crowdfunding for real estate." The Southern California company creates an online marketplace for accredited investors to pool their money and buy shares of office and apartment buildings and retail centers, and gives developers access to a broader pool of capital.

The concept is another form of syndication, but it is done solely online, and "you don't need to be a Rockefeller" to participate, says Realty Mogul co-founder and CEO Jilliene Helman.

Typically, deals the size of those put together by the company -- the latest is a group of five multifamily buildings in Los Angeles -- are the province of people who can invest $100,000 or more. But with Realty Mogul, investors with as little as $10,000 can participate.

The investments are fully vetted, and Realty Mogul over-raises to cover future repairs or improvements. Consequently, says Helman, there are no calls for investors to put up more money later.

Another key feature: monthly or quarterly distributions to investors. "We focus on cash flow," says Helman. "We are looking to be a source of income for our investors."

The new drive-time search tool, which has already been scooped up by the RE/MAX real estate network, gives buyers an easy, visual way to find houses within a specific drive-time from work, schools or other important locations. Drive times can be calculated at rush hour and at other times of the day or night.

"Drive time is a quality-of-life issue to buyers. For many, it's as important as the neighborhood and good schools," said RE/MAX Technology Strategy Officer John Smiley. "We're taking the guesswork out of one of consumers' most important purchase criteria: their commute."

RE/MAX plans to bring the app to its customers in all 50 states, beginning with New Jersey sometime in this year's first quarter.

To determine drive times using the new feature, which was developed by INRIX, buyers will enter the addresses of the locations most important to them as part of their search criteria on the RE/MAX website. The tool then automatically shows neighborhoods and properties that meet their desired travel time.

"In a world measured in miles, we measure it in minutes," said INRIX General Manager of GeoAnalytics Kevin Foreman in a news release.

According to the release, the program gets its traffic information "from a variety of public and private sources ranging from government road sensors, official accident and incident reports to real-time traffic speeds crowd-sourced from a community of approximately 100 million drivers."

Factors such as the day of the week, the season, local holidays, forecasted and actual weather, accidents and construction are also considered.

INRIX says its program has been found accurate to within 3 mph of actual traffic speeds under all driving conditions 24/7.