Most homebuyers know about standard home inspections, but few know much, if anything, about additional specialty inspections that also might be well-advised.
A geologist can inspect the home you want to buy for a variety of different hazards, including potential drainage problems and nearby landslide risks, according to Chris Wrightsman, CEO of LaRocca Inspection Associates, a home inspection company in Los Angeles.
"Any home that's on a hillside or near a hillside must have its geological conditions checked out by a specialist, and any home that has had previous earthquake damage reported should also be fully inspected by a geologist," Wrightsman says.
It's not only hillsides that are potentially troublesome. Homes in the flatlands should be geologically inspected, too, according to Chris Griffin, general manager at LaRocca.
That's because flatlands could be an ancient dry riverbed or flood channel or be subject to a hazard known as "liquefaction," Griffin explained. Liquefaction refers to soil that can become very soft and unstable as result of an earthquake, allowing a home to settle and sustain damage.
"The geological inspector can tell the buyer if the home is in a liquefaction zone or if there have been unstable soil conditions in the surrounding area in the past," Griffin says.
A costly inspection
A geological inspection can be relatively expensive, says Joshua Feffer, principal at Feffer Geological Consulting in Los Angeles. He says the fee to inspect an average home in the Los Angeles area might be about $1,300 to $1,600. A large property with a lot of land would cost even more.
The fees are that high because a full geologic inspection can include more than an examination of interior walls and floors. Feffer says his firm reviews historical records and the site where the home is situated.
"We go to the local building and safety office and try to find soil and geology reports and permits that may have been issued on the subject property and any surrounding properties that could give us some insight into how the slopes are behaving, what the underlying geology is, whether there's any fill or where there's been any distress to the structures," Feffer says.
The site inspection can include drainage, a swimming pool and nearby hills, among other area-specific factors. What's included in one locale might be different from what's included in another part of the city, state or country, so you should ask for a specifics when you hire a geologic inspector.
Related: Everything you need to know about home inspections
Water worries
While hillsides and flood plains are the chief concerns, anything to do with water or soil can become a problem and is worth a look, says Charles Spencer, an independent geological consultant in Lee's Summit, Missouri.
Whether it's a settling foundation or water intrusion through a cracked wall, the source of many problems is quite often outside the home, a realm the typical standard home inspection doesn't include.
"When we talk about the geologic environment," Spencer says, "we're talking about the soil, what properties it has and water, where it's coming from, how much there is and how it changes over time. It's usually the interaction between soil and water that causes most of the problems a homeowner typically would see."
Related issues include slope stability -- those hillsides, again -- and drainage problems that can result from groundwater as well as rainfall.
Water "doesn't have to be a big river" to cause a problem, Spencer says. It could be "a little drainage ditch going through the subdivision" or "soils that swell and put pressure against the house," he says.
Geologic inspectors
Geologic inspectors can be difficult to locate, especially in smaller communities since few homebuyers utilize these services.
One place to look for an inspector might be the local college since many adjunct faculty do consulting as a sideline, Spencer observes.
Spencer teaches geology and earth sciences at the University of Missouri -- Kansas City and says such classes can be eye-opening for future homebuyers.
"They're astounded at how the geologic environment can bite them as homeowners and how little they know about it," he says. "People just aren't as aware of the geologic environment as they ought to be."
The bottom line is that while geologic inspections aren't commonplace, savvy homebuyers might want to consider this opportunity to find out how water, soil, earthquake faults, hillsides and other naturally occurring environmental forces might affect the home they want to buy.
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