The lowest loan rates in 11 years have brought wannabe homebuyers off the bench and onto the playing field in droves. But low-cost mortgages don’t always help the market.

Housing economist Mark Fleming of First American, a major player in the title insurance field, says persistently low rates can put a damper on the supply of houses for sale.

“While historically low rates increase buying power and make it more affordable for potential buyers to purchase a home,” Fleming says, “they also discourage many existing homeowners from selling.”

In other words, low rates can help make housing both more affordable and more scarce. And when fewer houses are for sale, prices rise -- sometimes to the point that the benefit of the low rates is all but obliterated.

Here’s how Fleming explains it: In a falling-interest-rate environment, there’s lots of incentive to move up, because sellers can afford more house at the same, or even lower, cost. However, when rates are relatively flat, as they have been for the last four years or so, that incentive is taken away. To buy a newer, larger place, sellers either have to either bring cash to the table or be willing to take on a larger house payment -- or perhaps both. And that doesn’t even consider fees such as sales commissions.

So while low rates give rookies more buying power, they don’t do much for move-up buyers. “The only way existing homeowners can increase their house-buying power is through household income growth,” Fleming says, which is why more and more owners “have decided to stay put.”

The result is that the length of time people remain in their homes has jumped dramatically. Prior to the housing recession a dozen years ago, tenure was less than six years on average. In December, incumbency had nearly doubled to almost 12 years. That’s up 8% from just one year earlier.

That means fewer houses are on the market. According to the National Association of Home Builders, the inventory of houses for sale nationally has hit a near-record low of three months. (Generally, six months’ worth of inventory -- that is, how long it would take to sell off the current supply at the current rate -- is considered normal.) And in Seattle, only a few weeks’ worth of houses are currently for sale, said Glenn Kelman of realty brokerage chain Redfin on a recent earnings call with investors.

Kelman, based in Seattle, is convinced that the city’s inventory shortage is so extreme that “the most intensive bidding wars” in two years are on the way.

While Zillow reported recently that the number of houses selling above list price is at a three-month low -- only 1 in 5 are now drawing multiple bids -- Kelman said supply deficits are no longer confined to a few major cities.

Shortages are widespread, he said, adding that he was told recently that 30 buyers made offers on a property -- a mobile home, actually -- in a “far-flung” area of Oregon.

But there’s a second problem that exacerbates the lack of inventory: People who would otherwise put their places up for sale are holding back because they don’t have anywhere to go. If they can’t find another place that fits their needs at a price they can afford, they simply stay home.

Meanwhile, as buyers battle over what little is for sale, prices continue to mount -- absorbing some or all of the savings resulting from lower loan costs. Prices accelerated last fall, with December recording the largest single-month gain in more than six years, according to housing finance analytics firm Black Knight.

Black Knight says for all of last year, prices rose 4.7%, or nearly $13,000 on average. And prices in the lower end of the market rose at an even greater clip of 6.6%. The NAHB points out that for every $1,000 increase in a home’s price, nearly 159,000 households nationwide are effectively precluded from buying that place.

Of course, the number of those priced out varies from place to place. But multiplying Black Knight’s $13,000 price increase by the number of NAHB’s priced-out households means over 2 million families no longer have the income necessary to qualify for financing on the average house.

The same priced-out scenario holds true for mortgage rates: A quarter percentage point increase would drive some 1.3 million households out of the market for the median-priced newly constructed house, the NAHB says.

How all this plays out in the long run is anybody’s guess. Right now, the one wild card that could help open up the market is the new home sector, which should give buyers more choices. The more new places that are built, the less pressure there is on resales.

Starts last year dipped a tad from 2018. But the NAHB is predicting that shovels will break ground for 1.3 million units this year, including 920,000 single-family houses. And in 2021, it expects 925,000 more detached houses to be built.

Builders are not just putting up mega-mansions, either. They’re going smaller. Not only has the size of new homes fallen for four consecutive years -- to an average of 2,520 square feet, the smallest since 2011 -- the number of homes with three-plus bedrooms, three-plus bathrooms and three-car garages are down, though not exactly in free-fall.

The average new home is now only 20 square feet larger than in 2007.

You’re out for a Sunday drive with your significant other. You turn the corner, and BAM, there it is: your dream house. Better yet, there’s a For Sale sign in the lawn.

You didn’t expect such good fortune. You were going to hunt for a home of your own when your current lease expires in eight months. But your dream place is for sale right now -- and as it turns out, at a price you can handle.

You have 240 days to go on your lease, and the place is certain to be sold by then. So what can you do?

One option is to buy the house and sublet your rental to someone else. In that situation, you become a landlord. And therein lies the rub. If your tenant doesn’t pay their rent, or is habitually late, you are still responsible for paying your own landlord until your lease expires.

But let’s back up a moment. Your first step is to determine whether or not you can sublet. Check your lease to see what it has to say on the subject. And while you’re at it, check the laws in your community.

Even if you are within your legal rights to sublet, it’s always a good idea to let your landlord know. She may object, in which case you’ll either have to drop the idea or go to court, say the folks at ApartmentList, a free service that helps people find rentals.

But let’s say your landlord agrees. After all, the alternative could be a disgruntled tenant at best -- or, if you simply break the lease and move out, lost rent at worst. (By the way, if you do move out clandestinely in the middle of the night, you’ll not only lose your deposit, but your rental record will be tarnished forever, making it difficult to find another place to rent, should the need ever arise.)

Property manager Wallace Gibson advises her Charlottesville, Virginia, clients to be understanding. “Situations arise and you should do your best to work with your tenants to find a solution that satisfies everybody,” she says. “If you’re not willing to be flexible, you may find word-of-mouth can hurt you, and finding tenants can be much more difficult.”

So now the ball’s back in your court. Your next step is finding a viable tenant.

One way is to search online bulletin boards like Nextdoor and Craigslist. You can also run an ad in your local paper or, if you’re near a college or hospital, put your place in the hat with their housing offices. Another possibility is to tack a notice on local restaurants’ or grocery stores’ bulletin boards.

Once you’ve found two or three candidates who seem rent-worthy, check them out thoroughly. Here, references, credit checks, rental histories, even a criminal background search are all in order.

A thorough screening process may be somewhat costly, but it’s an absolute necessity to protect yourself against a bad apple who fails to pay rent and leaves you holding the bag. Consequently, you’ll want to know if they’ve been the subject of previous evictions, ever failed to pay rent or been arrested and convicted of a crime.

At this point, some landlords might want to screen your candidates themselves. If they know what they’re doing, they should be better at it than a novice like you. In fact, if they’re going to all that trouble, maybe they’ll let you out of your lease altogether and sign up one of your prospects to replace you.

If the landlord wants you to remain as a “sublessor,” you should insist on a lease with your “sublessee.” A handshake just won’t do, even if the guy taking over your lease is your best friend. You can find standard lease forms at your local office supply store, or perhaps your landlord will allow you to use one.

Finally, make sure you obtain a security deposit. This will give you at least one month’s cushion should your tenant miss a payment or, like you, decide to move out early.

As you can see, subletting can work, but it is fraught with risk. There’s no guarantee your subtenant won’t experience a life change -- a new job in another city, for example, or a major illness in a loved one back home -- so you could be stuck paying rent for a place you no longer occupy, as well as the mortgage for the house that started this whole process in the first place.

And if your renter turns out to be a dud, or even causes a full-on fiasco, you’re still responsible -- not only for the rent, but also any damages. So if you decide to go this route, proceed carefully.

The Trump administration’s moves to change -- some say “gut” -- the nation’s fair housing policies may have awakened a sleeping giant.

And the reason is pretty straightforward: It’s simply bad for business.

Besides being unfair, discrimination against consumers on the basis of race, gender or income means fewer people will be renting or buying houses.

Among the fair housing building blocks the administration has been trying to weaken are the long-standing Fair Housing and the Community Reinvestment Acts, as well as the Consumer Financial Protection Bureau, which was created only a decade ago in response to the mortgage crisis, largely to protect borrowers.

Responses from proponents of federal protections have ranged from jawboning by consumer advocates and real estate trade groups to congressional hearings. California is going even further, by proposing to create its own version of the CFPB to make up for what it perceives as the federal watchdog taking its eye off the ball.

“As the Trump administration undermines and weakens the rules that protect consumers from predatory businesses, California is filling the void and stepping up to protect families and consumers,” Gov. Gavin Newsom told local media recently.

The Golden State’s proposed Department of Financial Protection and Innovation reportedly will be given more staff and money than the current Department of Business Oversight, which it would replace.

The state is going its own way because the White House is challenging the structure of the CFPB, arguing that it infringes on the power of the president. The case is now before the Supreme Court.

“The structure of the Bureau, including the for-cause restriction on the removal of its single director, violates the Constitution’s separation of powers,” the administration is arguing. “The United States previously informed this court that it has also concluded the statutory restriction on the president’s authority to remove the director violates the Constitution’s separation of powers, and that the question would warrant this Court’s review in an appropriate case.”

Consumer advocates are also rankled by recent changes to the Fair Housing Act’s Affirmatively Furthering Fair Housing standard, saying they eviscerate fair housing protections.

According to an analysis by the Mortgage Bankers Association, the proposed FHA changes “would discontinue rules promulgated by the Obama administration that require communities to address racial discrimination issues in housing. The rule proposes to reduce regulatory burdens to governments by eliminating an assessment tool used to map racial segregation.”

After a quick huddle with the Department of Housing and Urban Development, another prominent housing trade group, the National Association of Realtors, came out reaffirming the group’s own commitment to fair housing.

Elsewhere, Sam Tepperman-Gelfant, deputy managing attorney at nonprofit Public Advocates, said, “The proposal would further an already devastating affordable housing crisis caused by policies that put the profits of developers, speculators and billionaires over our right to have a place to call home.”

And Malcolm Torrejon Chu, director of programs at the Right to the City Alliance, said that “the proposed changes will further target communities of color and increase racist discriminatory housing policies.”

Meanwhile, upcoming changes to the Community Reinvestment Act, which has been in effect since 1977 and was last updated in 1995, have consumer advocates crying foul and one key congresswoman alleging cheating.

In December, the Federal Deposit Insurance Corporation and the Office of the Comptroller of the Currency proposed to “modernize” the CRA to ensure “increased bank activity in low- and moderate-income communities where there is significant need for credit, more responsible lending, greater access to banking services, and improvements to critical infrastructure.”

But consumer groups think the changes will only weaken the CRA.

What the changes will really do, the National Community Reinvestment Coalition maintains, is “weaken affordable housing standards” by devaluing bank branches in low- and moderate-income neighborhoods, scaling back bank accountability and excusing small banks from rigorous CRA exams.

“There is no doubt that these proposed changes will be disastrous for low- to moderate-income communities,” says NCRC chief executive Jesse Van Tol.

The rule will become effective at the end of the period allowed for receiving comments, but one congressional housing advocate thinks there is some hanky-panky going on. House Financial Services Committee Chair Maxine Waters, D-Calif., is worried that someone has been stuffing the ballot box, seeking to validate changes to the landmark bill.

Waters, whose committee recently held a hearing on the proposed changes, has written to the Comptroller of the Currency and the chairman of the FDIC, saying “certain special interest groups have submitted comments in other rule-makings while posing as consumers, small-business owners and other stakeholders. These fraudulent comments undermine legitimate debate on proposed rules by creating the false appearance that a position has widespread, grassroots support.”

Cheating like this might not seem as momentous as baseball’s sign-stealing crisis, but the CRA has a lot of fans -- especially considering it can be used to challenge big banking mergers, often causing the banks to open their wallets to promise more mortgage money for more people.

Waters also accused regulators of trying to push the changes through “as soon as possible” by cutting the customary 120-day comment period in half.

On the substances of the proposed changes, she maintains the Community Reinvestment Act would become the “Community Disinvestment Act,” and would lead to a “widespread” retreat of bank investment in these communities.

-- Freelance writer Mark Fogarty contributed to the writing of this column.