NEW YORK (This Old House) - Charles Bellefontaine found out the hard way the value of a good home inspection. In 1991, Bellefontaine and his wife, Loretta, signed a contract to buy a three-bedroom, one-bath Georgian-style house in Elmhurst, Illinois.

A framing carpenter, he figured he had enough experience to size up the property for potential shortcomings. So to save money, Bellefontaine skipped hiring an inspector and handled the task himself.

He declared the house fit, and the couple completed the purchase.

Within a year, Bellefontaine found out how wrong he was: A leaky bathtub on the second floor damaged the kitchen ceiling below, an improperly sized circuit breaker posed a fire hazard, and the roof needed to be replaced.

Buying the home had stretched the couple's finances so perilously that they had to borrow money from Loretta's mother to pay for the repairs.

"We hadn't been married that long, and you can imagine how that incident went over with the family," Bellefontaine says. "I may have known something about construction, but I did not know how to thoroughly inspect the property." Loretta puts it more succinctly: "He was a know-it-all, and we paid for it."

Fortunately, most people don't attempt their own home inspections. But even hiring a professional doesn't guarantee that a newly purchased house isn't harboring unpleasant surprises.

By and large, home inspectors are poorly regulated, and the level of performance varies widely. Only 14 states require licenses, according to the American Society of Home Inspectors (ASHI), a trade group based in Des Plaines, Illinois.

Among those that do, few follow the lead of New Jersey, where inspectors must pass a lengthy written test, perform as many as 400 inspections, and in some cases complete a training program at a state-approved school before being accredited.

More common is the situation in Georgia and Tennessee, where home inspectors can be certified without evidence of any prior experience. Many states have no certification requirements at all.

Here's a list of steps you can take to ensure that you get the most from a home inspection.

1. Make sure the real estate contract includes an inspection clause. Typically, contracts allow home buyers 10 or so days after signing to have the property inspected. But that's not always the case, so it's important that the contract include a home-inspection clause. The results of the inspection can be used to ask the seller to fix trouble spots, or to adjust the selling price to cover the cost of necessary repairs.

2. Get references. Because state laws regulating the licensing of inspectors are generally toothless, certification from trade associations is often a better barometer of an inspector's experience and skills.

ASHI's Web site (www.ashi.org) maintains a list of certified inspectors, searchable by Zip code. Word of mouth is still the most common way to find an inspector. But even if the recommendation comes from a friend or real estate agent, it's a good idea to check for certification, call references, and consult the local Better Business Bureau to make sure previous jobs have been without incident.

3. Demand a thorough job. Only about half the states have laws stipulating exactly what must be covered during an inspection (for information about your state, see Inspection Resources). A thorough job should include a complete assessment of the interior and exterior of the house, from roof to foundation, as well as a performance analysis of the heating, plumbing, and air-conditioning and electrical systems.

Some crawl spaces may be too small or too dangerous for inspectors to wriggle into; expect to be told about any parts of the house that weren't examined.

For a three-bedroom, two-bath home on up to an acre of land, a complete inspection should last about three hours and cost between $300 and $500, depending on the region of the country and the size of the house and property.

"Cost is a good indicator of how comprehensive the inspection is going to be," says Bellefontaine, whose experience prompted him to give up carpentry and become a home inspector himself. "An inspector can't afford to do a good inspection for $99."

One key reason: expensive equipment. A diligent home inspector carries a toolbox that includes carbon monoxide and natural gas detectors, moisture meters, outlet testers, voltage meters, and an array of measuring devices.

"The discount guys try to get away with not much more than a flashlight, ladder, and screwdriver. That's not enough," he says.

4. Get results in writing. The inspection report is an excellent gauge of how exhaustive the work is.

Examine a sample copy before hiring an inspector. If it's little more than a checklist, it's insufficient.

A complete report should be anywhere from 20 to even 100 pages long, describing in layman's terms what was observed and any problems that were uncovered. If there are serious structural issues, or any problems the inspector can't diagnose, the report should recommend further examination by a structural engineer or other specialist.

Some inspectors include estimates of the cost of repairs -- but it's illegal in most states (and considered a conflict of interest under ASHI and other trade-group rules) for inspectors to solicit repair business based on their findings. Make sure that the home inspector agrees to spend an hour or so with you to go over the details of the inspection and answer your questions.

5. Hold the inspector liable for missed problems. Inspection contracts tend to be minimalist documents, but they contain one critical piece of information: the inspector's liability if he fails to discover an existing problem with the house or property. In many cases, liability is limited to the cost of the inspection.

So if you paid $300 for the service, that's what the inspector is obliged to reimburse you, even if you turn up a $3,000 problem the day after you move in.

Faced with this situation, you can protect yourself by hiring an inspector who carries insurance that covers not only damage to the property during the inspection but also losses due to "errors and omissions."

To lock in those protections, it's vital that the contract call for binding arbitration. With litigation so expensive -- and, in the case of a small contractor like a home inspector, not likely to be particularly rewarding -- arbitration is the best way to safeguard your interests.

6. Don't skip an inspection just because the house is new. New-home buyers are more likely to forgo an inspection than purchasers of existing houses, even though they may have more to gain.

Because most new homes come with a one-year warranty, an inspection can unearth construction flaws covered under this agreement that might otherwise go unnoticed for a few years.

"Municipal building inspectors, who generally do a 15-minute run-through, are not likely to find these problems," says John Ghent, a Connecticut home inspector and past president of ASHI.

7. Consider an inspection even if you're the seller. If you need to sell a house quickly -- perhaps you're relocating for a job or have already purchased a new property — you may be able to save time by having the place inspected first.

That way, you can find and fix any problems that might slow down the sale. "If a seller needs a smooth and fast transaction, they should do a home inspection before putting the property on the market," says Chris Ballard, owner of Century 21 Gold Medal Realty in Atlanta.

"They'll know what issues they may have to address and be able to take care of them before they become an issue."

Home inspectors acknowledge that whether a house is new or old, there are certain potential trouble spots that can be nearly impossible to discern, such as water intrusion that has been plastered over, cracks in concrete slabs that are concealed by floor coverings, or damage to walls that is hidden behind a careful paint job.

But they argue that flaws like these are rare.

"What a good inspector is looking for, and what he builds his reputation on, is the things that will cost buyers $10,000, $20,000, $30,000 when they move in," says Mike Casey, an instructor at Inspection Training Associates in Manassas, Virginia. "If an inspector is skilled, he finds those things."