If you're buying a home, you'd be remiss to forego a professional home inspection. An inspection can identify potentially costly problems with the home that you and your favorite handyman might miss. That being said, home inspections aren't foolproof. Here's why.

TUTORIAL: Buying A Home

Things Home Inspectors Won't Examine
The two major trade associations for home inspectors, the National Association of Home Inspectors (NAHI) and the American Society of Home Inspectors (ASHI), both have standards of practice that specifically describe what home inspectors are and are not required to examine. A partial list of things inspectors likely won't examine includes pools, spas, fencing, accessory buildings, wells, pumps, sprinkler systems, washing machine connections, alarm systems, heat exchangers, humidifiers and dehumidifiers, window AC units, and appliances. They also won't examine anything that's not readily accessible.

Bob Sisson, ASHI Certified Inspector and owner of Inspections by Bob, says, "Home inspections are generally described as a non-technically exhaustive visual inspection. We will not do anything destructive to make an observation."

He adds that home inspectors will not enter areas they consider a safety hazard, such as areas whose point of access does not meet minimum opening sizes or clearance for safe egress or places that appear to contain hazardous chemicals, molds or asbestos. Crawl spaces, attics and roofs are often excluded from inspections as a result of these safety hazards.

Reasons for Exclusion
In addition to the safety hazard issue, home inspectors are not usually experts when it comes to many of a home's specific components. They won't offer an opinion on these items because they aren't qualified.

"I get calls from home inspectors when they find a structural issue they don't feel comfortable making an assessment on," says Scott Ogren, professional engineer at Ogren Engineering. "While they can look at a structure that appears to be performing normally and say that it is fine, when there is an obvious structural issue that needs to be addressed, that's when it's time to call in a professional and seek the advice of someone who specializes in the structural aspects of a house," he adds.

Home inspectors can't do the jobs of engineers or other professionals. Inspectors are not appraisers, so they won't offer an opinion on the home's value. They aren't code enforcers, so they may not be able to identify things that don't comply with building codes and ordinances. They don't inspect for pests or mold and they won't advise you on whether you should proceed with your purchase of the property.

Additional Exclusions
Home inspectors, like all professionals, have to protect themselves against safety and liability hazards. Home inspectors also can't be expected to be fortune tellers.

Home inspectors don't have to guess how many years of service are left in, say, a furnace or water heater, nor can you expect them to identify latent defects. They will not necessarily be able to tell you how much a problem will cost to fix or how to fix it. While the air conditioner may work on the day the inspector examines it, any system can fail at any time without warning.

Properties with more than four units pose additional problems. If you're buying property in a condo building or a homeowners' association, the inspection will probably not cover the exterior or roof of a condo building or the common areas of homeowners' associations (HOA). The inspection will be limited to the specific areas that you as a potential homeowner would be individually responsible for. (For more details on HOAs, read 9 Things You Need To Know About Homeowners' Associations.)

Protecting Your Investment
When there are so many things that an inspection doesn't cover, how can you be sure that an inspection gives you enough information to make an informed decision, and how can you protect yourself against an inspection's shortcomings?

For concerns about HOA properties, prospective buyers can examine an HOA's meeting notes and reserve funding studies to see if the HOA is financially prepared to make repairs and if there are any known issues. For particular areas of concern with any property, buyers can hire a specialist. If a home inspection or your own instincts indicate a possible problem with the basement, for example, you can hire a basement inspector.

"Inspectors do inspect basements. However, many times the basement part of their inspections is less than adequate," says Doug Lynch, president of A-1 Basement Solutions.

New homeowners often call him into their homes for a basement waterproofing estimate after a heavy rain. In many cases, inspectors told the homeowners that while there was some indication of past water seepage, it wasn't necessarily a large concern. After the sale closed, however, the new homeowners found themselves with the cost of waterproofing the basement.

"A comprehensive basement inspection including water intrusion, mold inspection and structural examination by a basement expert should be considered before purchasing a home," says Lynch.

New York homeowner Robyn Federman says she learned the hard way that home inspectors in her state do not inspect chimneys. She wound up with an expensive repair bill and says she wouldn't have bought the house or would have negotiated differently had she known that the chimney had a problem.

Federman isn't alone in her experience. Mark T. McSweeney, CAE and executive director of the National Chimney Sweep Guild, says chimneys and their venting systems are one of the most commonly under-inspected components of a home.

"The National Chimney Sweep Guild, the Chimney Safety Institute of America and the National Fire Protection Association all recommend annual inspections to ensure these systems are operating as safely and efficiently as possible. In the case of a sale or transfer of property, a Level 2 inspection is recommended which includes a visual inspection, typically by video scanning, in order to examine the internal surfaces and joints of all flue liners incorporated within the chimney."

The Bottom Line
There's no question that it's expensive to pay for additional inspections on top of a home inspection. However, their cost is relatively small compared to the cost of home repairs associated with hidden problems. To go into your home purchase knowing that you've done all you can to make a sound decision and to protect your investment, be aware of what basic home inspections don't cover and plan to compensate accordingly.