House sizes are coming down, but the size of apartments is going up.

According to preliminary data from the Census Bureau, the square footage of new single-family homes in last year’s final quarter continued its downward trend after years of marching ever higher.

The median floor area of a single-family home was 2,371 square feet in the fourth quarter of 2017. In the fourth quarter of 2016, the median was 2,440 square feet. (Median is more representative than average, because the figure is not skewed by outlier super-size houses.)

The lowest median point in the most recent cycle was 2,135 square feet in 2009.

“The post-recession increase in single-family home size is consistent with the historical pattern coming out of recessions,” explains Robert Dietz, chief economist at the National Association of Home Builders.

Typically, the size of new homes falls prior to and during a recession as buyers tighten budgets. Then sizes rise as high-end buyers, who face fewer credit constraints, return to the housing market in relatively greater proportions.

Dietz reports that the normal pattern was exacerbated during the current business cycle due to market weakness among first-time buyers and supply-side constraints in the building market. But the recent declines in size indicate that this part of the cycle has ended, he says, and house sizes will continue to trend lower as builders add more entry-level homes into their inventories.

On the other hand, apartment sizes are trending larger, as developers take aim at baby boomers, who are giving up their big houses for smaller -- but not too small -- apartments.

According to recent data from Transwestern, a full-service commercial realty firm based in Houston, the average one-bedroom apartment has 874 square feet, while two-bedroom units average 903 square feet, and three-bedrooms ring in at 976.

However, apartments in properties constructed in the last 12 months average 935 square feet for a one-bedroom, 945 square feet for a two-bedroom and 996 square feet for a three-bedroom.

To meet demand for the larger rentals, developers are building a larger percentage of three-bedroom units.

With apologies to Sports Illustrated, here are three signs that the real estate apocalypse is nigh:

-- David Sicilia, the Henry Kaufman Associate Professor of Financial History at the University of Maryland, believes that real estate agents will eventually go the way of the dodo. Asked by the school’s Terp magazine what mainstay of American life will have vanished in 25 years, Sicilia responded: “Realtors are headed for extinction.”

His reasoning: “The occupation owes its existence chiefly to the Multiple Listing Service, a former monopoly on market information that is rapidly migrating to the internet. Software is coming that will price to market with much greater precision and objectivity than real estate agents’ intuition. Video property tours make scouting from the laptop simple.”

For more serious, in-person visits to houses for sale, the professor envisions “bonded, paid-by-the-hour docents escorting prospective buyers through properties.” He also thinks “an increasingly friction-free economy will eliminate real estate agents’ enormous fees.”

-- 35 percent of buyers who took the plunge last year said they made an offer on their home without first seeing it in person, according to a December 2017 survey commissioned by Redfin. That’s up from 19 percent in June 2016. The survey found that millennials were the most likely to make a sight-unseen bid, reflecting their comfort level with relying on information they find online.

-- Another Redfin survey asked would-be buyers what they’d do if mortgage rates hit 5 percent. Six percent of respondents said they would drop out of the market altogether, and 25 percent would slow their plans to buy. But 20 percent said they would speed up their search and jump on a home they liked, for fear that rates would rise even higher.

-- When it’s cold outside, most homeowners turn up their electric or natural gas furnaces. But some of us -- 1.9 percent, the Census Bureau reports -- rely on wood for heat.

Most of the counties with a population of at least 65,000 where residents use wood to keep warm are in the West. A sampling of places that keep the fire burning: In Apache County, Arizona, 60.6 percent of dwellings are heated by wood; New Mexico’s McKinley County, 38.8 percent; California’s Mendocino County, 24.8 percent; New York’s St. Lawrence County, 17.5 percent (the only Eastern county in the top 10).

In less than two decades, America’s population will join Japan’s as the one of the oldest on Earth.

By 2035, the Census Bureau projects that older adults will edge out children in population size. People age 65 and over are expected to number 78 million, while children under age 18 will number 76.4 million.

Looking out farther, nearly 1 in 4 Americans will be 65 or older by 2060, the number of 85-plus adults will triple, and the country will add a half-million centenarians.

Japan currently has the world’s oldest population, where more than 1 in 4 people is at least 65 years old.

In the hit movie “Home Alone,” Macaulay Culkin went to great lengths to keep burglars Joe Pesci and Daniel Stern from robbing his home. Culkin’s character rigged the house with numerous booby traps, injuring the thieves many times over.

If we real-life homeowners tried that, and a robber or two was hurt because of the traps we laid, chances are good that we could be sued by the bad guys and maybe end up in jail ourselves.

According to the law, homeowners can use “reasonable force” to defend their properties from theft, violent attack on their person, or other types of unlawful aggression. The doctrine is often used as a defense in criminal trials and lawsuits.

But when someone uses excessive force, they are considered to have forfeited their right to use the law as a defense.

In cases of trespass, the lawful occupant of the property must demand the intruder leave. If they don’t exit, the occupant can then use reasonable force to make the bad guy depart. If they still don’t go, the occupant is permitted to raise the level of force. It is up to the thief to prove beyond a reasonable doubt that you used more force than was reasonable and necessary.

The good news is that burglars go out of their way to avoid bumping into occupants. Indeed, many will abandon a robbery attempt because they heard someone in the house or returning home, or hide to avoid discovery.

Fortunately, encounters are rare. Even though some burglars know the law regarding reasonable force, they often make several checks of the property to make sure they don’t meet anyone in the hall or coming down the steps, rifle in hand.

Even though the number of burglaries decreased 4.6 percent from 2015 to 2016, there were still 1.5 million that year, according to the FBI. Burglaries accounted for 19 percent of 2016’s known property crimes, with victims incurring $3.6 billion in losses.

And according to robbery expert Alan Young, thieves have discovered that “better” suburban neighborhoods are theirs for the taking; crime is no longer a problem relegated to “bad areas.”

“It’s pretty simple: Thieves have finally figured out that people in better areas have more things that are worth stealing,” says Young. He experienced repeated break-ins when rehabbing properties in the Nashville area, and went on to make protecting people and their homes his life’s work. With his engineer brother, he formed Armor Concepts to produce economical ways to secure residences.

Many homeowners install expensive alarm systems and keep a gun on the nightstand. But Young isn’t a fan of either option.

He points out that alarms only work once the intruder breaks down a window or door. Most robbers can be in and out in five minutes, he says, while police response time is often four times that long. And guns only work if you are home, and if the gun is handy at the crucial moment.

Young’s advice: Be proactive instead of reactive. “Take steps to keep (burglars) out in the first place,” he says.

Here are some steps you can take to protect yourself and your family:

-- I personally am not a gun fan, so I don’t recommend them. But I do like dogs, especially big ones that bark loudly at the slightest sound outside. They are great deterrents; thieves don’t like running into dogs any more than humans.

Absent a real dog, try running a continuous-loop recording of a dog barking. Not constant barking, but a loud, large woof every minute or two -- enough to keep the burglars away. Or try an outdoor device that triggers the recorded barking.

-- Secure your doors and windows. Make it harder for the bad guys to get in -- hard enough that they’ll decide to move on to a different target.

-- If you are gone for any period of time, consider a house sitter. That way, someone really will be home. At the very least, have a neighbor pick up your newspapers, mail and deliveries, or put them on hold until you return. Nothing says “I’m not here” like packages piling up on the porch. If you do hire a sitter, ask them to park their car in your driveway.

-- Put a timer on a couple of lamps, setting them to come on at dusk and go off at, say, midnight. To guard against power outages, consider solar timers.

-- Leave the light above your kitchen range on at all times. The kitchen is one room that tends to have lights on the most.

-- Exterior lights should be on motion sensors or timers, and mounted high enough so they can’t be reached without a ladder. A thief usually won’t put up a ladder because it is too conspicuous.

-- Put your TV on a timer so it goes on and off in the afternoon and again in the evening. Or at least leave a radio on -- to a talk station, as opposed to music. The broken pattern of human speech is more consistent with someone being at home.

-- If you have a landline, turn down your phone’s ringer so a long series of unanswered rings doesn’t draw attention. Your answering machine’s (or voicemail’s) message should be along the lines of, “We can’t get to the phone right now,” rather than “We’re out of town, but will call you back Tuesday!” And check your machine occasionally from wherever you are, so it doesn’t fill up -- tipping off callers that no one’s been home in a while.

Boosting your credit score before you secure a home loan can pay off big-time -- in some cases, to the tune of tens of thousands of dollars over the life of your mortgage.

The reason: Mortgage borrowers with higher credit scores tend to be offered lower loan rates, and even a small difference in your annual percentage rate, or APR, adds up over time.

LendingTree, an online mortgage marketplace, takes a look each month at what lenders on its site are charging for financing a home. The findings are eye-opening.

Take the average purchase-money mortgage, which, as its name suggests, is a loan taken out to buy a house. The average interest rate for this type of financing in December was 4.42 percent. But the average rate varied widely by credit score, also known as a FICO score after its originator: Fair, Isaac and Co.

For example, if you have a great credit score of 760 or above, the typical interest rate you would have paid in December was 4.26 percent. Drop down a few grades -- say, a score of 680 to 719 -- and the average interest rate is 4.56 percent.

That doesn’t sound like much of a difference. But over the life of your loan, 0.3 percent is considerable. At a 760 FICO, a borrower will pay $180,584 in interest over the life of the average loan, compared with $195,494 for a borrower with a 680 FICO. That’s $15,000 more over the same period.

Says Tendayi Kapfidze, LendingTree’s chief economist: “The benefits of improving your credit score are even greater when interest rates are rising, as lenders often pass on higher costs to borrowers with poorer credit first.”

The average loan amount for the borrower with the higher credit score is $252,000 -- a good bit higher than $217,000 for the borrower with the slightly lower score.

The average mortgage rate has gone up by half a percentage point in the last two years, says Kapfidze. However, borrowers with 760-plus credit scores saw a rate increase of just 0.4 percent, while those from 620 to 639 had their rates increase by twice as much.

Improving your FICO score is good whether rates go up or not. Whether you’re borrowing for a home, car or student loan, it’s worth your while.

Take Tanya Febrillet. A single working mom of two in Massachusetts, Febrillet wanted to step up to owning her own home. To get there, she used a little-known program offered by the Department of Housing and Urban Development called Family Self-Sufficiency, run locally by her public housing authority and Compass Working Capital.

After five years of hard work with a Compass financial coach, “Tanya paid down her debt, increased her annual income by nearly $8,000, improved her credit score by more than 140 points and built over $3,000 in savings,” according to a report on the program by Compass and the Preservation of Affordable Housing. She also bought a house, becoming the first person in her family to do so.

Using the LendingTree model and a credit-score boost similar to Febrillet’s, say, from 620 to 760, a borrower could save nearly $40,000 in interest costs over the life of a loan, going from $218,000 to $180,000.

There are many credit repair outfits to choose from, but it’s entirely possible to improve your score on your own. It’s not difficult to find out what the three main credit repositories -- Equifax, Experian and TransUnion -- look for in determining your score, and act accordingly. Also, many credit cards offer free looks at your credit score, and an analysis.

Some of the factors are obvious, like any overdue payments. Paying your bills on time is probably the most important step you can take to raise your score. But other steps are not so obvious. For example, a score takes into account the length of your credit history. So make sure that American Express account you started way back in college remains active.

The three bureaus also like it if you can demonstrate that your good credit habits extend beyond your credit cards. In fact, your FICO score may be hurt if you don’t have an installment loan, like a mortgage or car loan, that you pay down religiously every month.

Also, if you are shopping for credit, pay attention to how many times companies ask for your credit report. Too many requests in too short a time can be seen as a sign of financial instability, as can opening too many accounts too quickly.

You will get marked down if you use a high percentage of your available credit line, but rewarded for having a relatively large amount of unused credit.

You may not be able to raise your score by 140 points, but every little bit helps.

-- Freelance writer Mark Fogarty contributed to this report.