Many -- if not most -- homeowners aren’t prepared for a flood, tornado or other natural disaster. And neither, apparently, are their insurance companies.

Take California, where the California Earthquake Authority estimates $175 billion in residential damage would result from a recurrence of the “Big One” that struck San Francisco in 1906. Yet only $15 billion in damage would be covered by insurance, warns the CEA, a private nonprofit that offers earthquake coverage to Golden State residents.

Created by the state legislature in 1996, the CEA says it is financially strong enough to cover all claims it receives, should a repeat of the super-catastrophic quake occur.

But the magnitude 6.8 quake that hit Northridge, California, in 1994 caused so much damage that insurers paid out more in claims than they collected in premiums over the previous 30 years, bringing many dangerously close to insolvency, according to the trade journal Insurance Business America.

Steven Steckler, president of the Sentry Claims Group in Louisiana -- an independent adjusting service -- says most, if not all, insurance companies have the resources to cover their insured clients’ losses, largely because only about 10 percent of all homeowners have earthquake coverage. We’ll come back to that shortly.

But there’s another problem: Should another major quake strike -- and they have occurred in 42 states -- there’s “no way” companies could put enough boots on the ground to assess owners’ claims and get them the money they need to begin repairs, Steckler says.

For one thing, there just aren’t enough adjusters. For another, there isn’t enough infrastructure to support them. In a major quake, roads and bridges will be destroyed, so adjusters won’t be able to reach people.

At the same time, “you can’t just show up,” says Steckler. “First, you have to have structural engineers check the integrity of the property. Until they put a tag on the door indicating a place is safe to enter, everything is at a standstill.”

Now, about the lack of coverage. Many people don’t realize that a standard homeowner’s policy doesn’t cover earthquakes -- or floods, for that matter. You’ll need either a rider or a separate policy to cover damage from a quake, and yet another separate policy to cover flooding.

But quake and flood insurance is expensive, Steckler says. The deductibles on an earthquake policy are so high -- anywhere from 5 to 20 percent of the coverage amount -- that claims are often less then the deductible amount, especially in expensive areas like California. Consequently, homeowners end up paying the cost to repair their homes out of their own pockets.

Worse, perhaps, some people don’t even know what’s covered by their policies and what’s not. Even when people have coverage, 18 percent have never bothered to read their policies, a recent study by ValuePenguin found. A third believe their homeowner’s insurance covers floods.

The Insurance Information Institute figures upwards of 4 million houses are uninsured, and that two-thirds of all houses are underinsured, some by 60 percent.

Meanwhile, homeowners aren’t prepared, either. Most don’t take the precautions necessary to protect their homes, like raising places in flood-prone areas or tying all joists together so houses act as one unit in quake-prone regions.

At the height of the hurricane season, which stretches from June to November, 3 out of 4 owners in the riskiest coastal states believed they were prepared for whatever Mother Nature sent their way, according to a survey by ValuePenguin, a LendingTree subsidiary. But less than half had taken any precautions.

Hurricanes are deadly in a couple of ways: The high winds knock things over, and the tremendous amounts of rainfall and storm surge cause flooding. According to the insurance institute, flooding is the most common and costliest of all natural disasters. The National Flood Insurance Program says 90 percent of all natural disasters in the United States involve flooding.

But flooding can happen for any number of reasons, not just big rains. Pipes sometimes burst, dams break or snow melts too rapidly. And damage from just a few inches of water can be expensive to repair.

Standard homeowner’s insurance is a package policy covering both damage to property and liability or legal responsibility for any injuries and property damage policyholders or their families cause to other people. This includes damage caused by household pets.

A standard policy covers 16 disasters or “perils,” but neither flooding nor earthquakes are on the list. Flood coverage is available through independent agents from the National Flood Insurance Program, or through some private carriers. Earthquake coverage can be added to your standard policy as an endorsement (aka a rider) or purchased as a separate policy.

To make sure you are covered during any kind of cataclysmic event, Steckler suggests looking for firms with a rating of “A-plus” or “Excellent” in the state where you live. These firms are the strongest financially, and do a good job investing their money, he says.

Another consideration is whether a company is “admitted” or “nonadmitted.” The former shares in a state’s guarantee fund, which will cover you if the company can’t meet all legitimate claims. The latter are large, standalone companies which, while there is no guarantee they will cover all claims, are often the only ones writing policies in high-risk areas.

Parents can take a number of steps to help their offspring purchase their first homes. They can donate money for a down payment, co-sign on a mortgage or pay off their student loans.

But Mom and Dad also can get in the way. For one thing, they can offer advice that was sound when they bought their own house years ago, but no longer holds water in today’s market. And they can insert themselves into the entire process, instead of letting Junior or Missy make their own decisions.

But worst of all, says Massachusetts real estate pro Dana Bull, well-intentioned parents can “steamroll” all their children’s ideas.

It’s not that adult children don’t want their parents’ input and advice -- they do, says Bull, who hangs her shingle with Sagan Harborside, a Sotheby’s International Realty franchise. But all too often, she says, parents “end up overstepping their bounds.”

Bull was 22 and working in the architectural field when she bought her first place, a condominium apartment in a circa-1784 house, with her then-boyfriend (now husband). Her parent’s didn’t approve: They had always purchased new homes, and worried that their daughter was making a big mistake buying such an old place.

“They were apprehensive,” Bull recalls. “They were concerned that the old structure could have plumbing and electrical issues, and that I was making such a major decision at such a young age. They also were anxious about the fact that my boyfriend and I were buying together: ‘What if things between us went south?’”

The couple went on to buy a number of properties together, and at age 25, she transitioned full-time into real estate. Now 30, she works with a lot of younger buyers, and says she often “feels like a therapist” when their parents become too involved.

She sees it mostly when Mom and Dad tag along during house-hunting outings, and again during the home inspection.

“The kids may love the house, but if the parents don’t approve, the kids freeze. All they really want is their parents’ approval,” Bull says. “The parents have good intentions, but their kids are adults who know what they want and they are fully capable of making their own decisions.”

As Bull sees it, “the best thing parents can do is to provide a framework so their children can make sound decisions.”

Parents need to realize that certain things are beyond their level of expertise, Bull advises. “They are far better off suggesting that the kids find experts in their respective fields. That means urging them to build a good team of real estate professionals, starting with their choice of agents and including solid, trustworthy lenders, home inspectors and possibly even lawyers.

“Having the right people who can advocate on your behalf about the things you and your parents don’t know much about is key,” the Massachusetts agent says. “Young buyers love the idea of Dad coming along on the home inspection, and they value his opinion. But the real expert is the professional.”

Stepping back isn’t easy for some parents, who often fear their adult children will make the same mistakes they did. But that’s the way “kids” of any age learn -- just the way Mom and Dad did.

Still, if you want to be in the picture -- and are asked to be -- then be involved from the get-go, Bull suggests. “Asking ‘Why didn’t you think about this or that?’ isn’t helpful, especially in the middle of the process. If you want to be part of the journey, do so from the beginning.”

There are any number of ways parents can help their children. But co-signing on a loan isn’t the best choice: If your name is on the mortgage, you are just as liable for the payments as your children. Consequently, if they should falter, you’ll have to make the payments, or your credit will be impacted.

If you can afford it, a monetary gift to help with or cover the entire down payment is a better option. But don’t make it a loan, even secretively. The lender will want a complete paper trail of where the money came from, and the borrower will have to state in writing that the money need not be paid back.

Far and away the best thing you can do for your children is to be sure they pay off their high-interest debt as quickly as possible before they even think about buying a house.

“If parents are going to help their children financially, they should start with high-interest debt that might be accrued during and after college,” says Thomas O’Shaughnessy, head of research at Clever Real Estate, a nationwide referral service that connects consumers to agents.

Clever’s research shows that 48% of undergraduates with student debt plan to delay homeownership by seven years. Moreover, they are eight times more likely to add a personal loan to their debt load, and seven times more likely to be using high-interest credit cards at the same time.

Worse, perhaps, 56% of college students don’t know the interest rates on their student loans. And most college students underestimate, by five years, how long it will take to pay off that debt.

So, while parents can help their children with some or all of their down payment or by joining them on a mortgage, O’Shaughnessy advises, they are far better off being certain the kids are in a financially stable place to afford their monthly mortgage payments.

Kevin Casey was “blown away” this summer when nearly 400 people came out to have a peek at two of his firm’s accessory dwelling unit projects.

Now that California Gov. Gavin Newsom has signed new legislation that will make ADUs -- aka granny flats, in-law suites, casitas or any number of other monikers -- more accessible for Golden Staters, Casey is absolutely ecstatic.

“The state is finally seeing the value of ADUs and we couldn’t be happier,” said Casey, the owner of design-build firm New Avenue Homes, in an email. New Avenue has built more than 100 ADUs, mostly in Northern California, at prices ranging from $130,000 to $750,000. “We’ve always been sure of one thing: Accessory dwellings will revolutionize housing.”

For the uninitiated, ADUs are basically small houses or apartments that are built on the same lot as a larger single-family house. They can take the form of individual buildings or converted attics, basements or garages. But in all cases, they are self-contained, independent living spaces.

While they’ve only become prominent over the last few years, they have been with us, in some form or another, for much longer.

Casey pointed out that Arthur Fonzarelli -- better known as Fonzie -- of “Happy Days” lived above the Cunninghams’ garage. And in “Full House,” Tanner family friend Joey resided in a room in the family’s garage, while brother-in-law Jesse and his bride lived upstairs in an attic studio apartment.

Today, proponents of accessory units believe they will help ease housing shortages by expanding the options for people of all ages. They are aimed at young renters who don’t need a lot of space; moms, dads or other relatives who want to be closer to their loved ones; or caregivers who need to be nearby. And they offer an opportunity for their owners to generate a little side income.

Many communities throughout the country have been relaxing their restrictions against ADUs, and some states have been encouraging their local jurisdictions to allow them. According to AARP, the cities of Atlanta, Austin, Denver, Houston, Philadelphia, Phoenix and Seattle now allow accessory units. Oregon requires cities and counties of a certain size to allow them in single-family neighborhoods, New Hampshire says they must be allowed in nearly every single-family neighborhood, and Boston-area communities are slicing red tape so units can be built.

But California is leading the way. In 2017, the state required all cities and counties to allow ADUs as long as the property owner secured a building permit. In September, San Jose named design firm Abodu as its first pre-approved “backyard” homebuilder under its ADU master plan. “We won’t solve our housing crisis $650,000 at a time,” said San Jose Mayor Sam Liccardo, referring to high-end single-family houses.

Now, Gov. Newsom has signed several bills that will make it even easier for property owners to build accessory units. One eliminates occupancy requirements; another makes it easier to add not one, but two ADUs as long as they contain at least 800 square feet of floor space; and a third creates a tiered permit structure based on the size of the unit and its location.

Legislation like this will help boost ADU production in the state, which already has the most in the country. For example, between 2015 and 2018, applications for 8,279 ADU permits were received by the Los Angeles Planning Department alone. The number of permit requests jumped from 282 in 2015 to 3,922 in 2018.

Other California cities have been slower on the uptake, but the number of ADU permit applications is still rising: from none in Long Beach in 2015 to 42 in 2017; from 33 to 247 in Oakland, and from 41 to 595 in San Francisco.

The 2017 law was “a big deal,” Casey told me on the phone. “We’ve been talking about this for decades, but that was the turning point. It’s almost like the whole state got the memo. California has made so much progress.”

With progress, though, comes the opportunity for shysters to enter the market. Consequently, anyone thinking of adding a second dwelling on their property should proceed carefully, warns Casey. “A couple of hundred startups are all planning to jump on the bandwagon,” he says. “If people aren’t careful, hucksters and amateurs will disappear with their deposits.”

For starters, do your research. Look for an experienced company that knows your city’s rules, as well as the state’s, knows design, and won’t hit you with surprise fees or delays.

Some firms, New Avenue and Abodu among them, handle the entire permitting process, guarantee a fixed price and can deliver a factory-built unit to a client’s backyard within two weeks. A complete 495-square-foot Abodu model starts at $199,000. Another outfit, Modative of Culver City, California, designs, permits and builds its units.

For a good understanding of ADUs, AARP has two great publications: “The ABCs of ADUs” and “Accessory Dwelling Units: A Step-by-Step Guide.” They are free to members at AARP.org/ADU. Also, the July-August 2018 issue of Realtor, the official publication of the National Association of Realtors, has a good piece on ADU basics.