8 Things a Standard Home Inspection Won’t Catch in the Treasure Valley

Radon is a gas you can’t see or smell. A visual inspection won’t measure it. The Idaho Department of Health and Welfare points homeowners toward test kits or certified radon professionals.

The U.S. Environmental Protection Agency (EPA) map places Ada, Canyon, Owyhee and Payette counties in Zone 2, “Moderate potential”; Gem County in Zone 3, “Low potential”; and nearby Boise, Elmore and Valley counties in Zone 1, “Highest potential.” EPA describes Zone 2 as average indoor radon levels that may be between 2 and 4 picocuries per liter (pCi/L), Zone 3 as less than 2 pCi/L, and Zone 1 as greater than 4 pCi/L.

Those are county-level potential categories, not measurements of your home. EPA says, “All homes should be tested for radon.” I wouldn’t use a county color, a newer build or a neighbor’s result as a substitute for a test.

Who can check it: A certified radon testing professional. Ask about the testing protocol and how to interpret the result.

A sink draining during the inspection doesn’t show the inside of the pipe beneath the yard. A separate sewer scope uses a camera to look for visible problems such as roots, breaks or standing water in the lateral line leading away from the home.

If the home uses septic instead of public sewer, that’s a different follow-up. A camera view of the pipe doesn’t evaluate the whole tank and drainfield. Central District Health has septic records and resources for Ada, Boise, Elmore and Valley counties; for another county, start with its local public health district.

I’d first confirm which system serves the property, then ask what a specialist can inspect and what will remain inaccessible. That’s more useful than assuming “plumbing checked” means everything underground was checked too.

Who can check it: A sewer-scope professional for the lateral line; a qualified septic professional for the tank and drainfield, with records from the public health district.

If you’re looking at a property served by a private well around Kuna, Star, Eagle or the Caldwell area, I’d separate two questions: what’s in the water, and how is the well equipment performing? Clear water and a working faucet don’t answer both.

The Idaho Department of Environmental Quality (DEQ) recommends testing private wells for nitrate and bacteria at least annually and asking about other contaminants relevant to the area. Its guidance directs owners to Idaho-certified laboratories and the local public health district.

A general home inspection doesn’t establish water quality or the reliability of the source. Lab sampling and an equipment or production evaluation are separate conversations, and neither is replaced by a quick look at the pressure tank.

Who can check it: An Idaho-certified drinking-water laboratory for samples, the public health district for local testing guidance, and a qualified well contractor for equipment and production questions.

A green lawn doesn’t tell you where the irrigation water comes from, who maintains the delivery system or what the account covers. A standard inspection generally doesn’t include irrigation or buried sprinkler lines.

The Nampa & Meridian Irrigation District says its typical water season runs from mid-April to early October, depending on supply. That means an off-season visit may tell you very little about operating pressure or leaks. The district also explains that its assessment is based on the allocated water right, not water usage, and that private lawn sprinklers aren’t maintained by the district.

I’d ask the actual provider to explain service, delivery and current account information, then ask a sprinkler professional about the private system. Different districts and privately operated systems can work differently. A home inspector isn’t verifying water shares or interpreting water rights.

Who can check it: The serving irrigation district or system operator for delivery and account questions; an irrigation contractor for the private equipment. If there’s an HOA, ask it to explain any separate irrigation charge.

Inspectors do look for visible water intrusion and drainage problems, where accessible. What they can’t do is make a dry inspection day show how the crawlspace behaves during a different season.

Ada County Emergency Management notes that a rising water table can flood a crawlspace even when outside floodwater doesn’t reach the home. That’s a useful distinction in an irrigated valley: surface flooding and groundwater aren’t the same thing.

I’d ask about past moisture, drainage work and any areas the inspector couldn’t reach. For floodplain information, the local floodplain office is a separate stop. A visual inspection isn’t a floodplain determination, and a map alone doesn’t diagnose crawlspace moisture.

Who can check it: A qualified drainage or building-moisture specialist, with an engineer if the findings call for one; the city or county floodplain office for mapped flood information.

A home inspector may flag cracks, uneven floors or other signs of possible movement. That isn’t the same as identifying the soil beneath the foundation, explaining the cause or deciding whether movement is continuing.

This matters on a site-by-site basis, especially when slopes or previous earthwork raise questions. The City of Boise’s geotechnical guidance treats soils evaluation for hillside construction as specialist work. That construction guidance isn’t an inspection rule for every existing home, but it shows why a general visual report isn’t a soil study.

I wouldn’t label an entire city as having “bad soil,” or diagnose a crack from a photo. If the report raises a concern, I’d want the appropriate engineer to explain what it means for that particular site.

Who can check it: A structural engineer for the building and a geotechnical engineer for soil or slope questions, depending on the findings.

An inspector can observe accessible insulation and operate heating or cooling equipment when conditions allow. That doesn’t measure all the air escaping through the building or tell you how comfortable each room will be in January or July.

Idaho Power’s home energy audit is an example of a separate assessment. It uses a home performance specialist and, where appropriate, a blower-door test to locate air leaks. Program eligibility and testing limitations apply, so I wouldn’t assume a home you’re considering automatically qualifies.

If comfort is a concern, I’d ask about an independent energy assessment and an HVAC evaluation where needed. Utility history can provide context, but someone else’s thermostat settings and usage won’t predict your bill.

Who can check it: A qualified home performance specialist for leakage and insulation questions; an HVAC professional for equipment and air-distribution concerns.

If a fireplace or wood stove is part of what you like about a Treasure Valley home, I’d ask how far the inspection goes. A look at the visible fireplace and chimney doesn’t necessarily include the inside of the flue, a camera scan or a draft test.

InterNACHI’s fireplace inspection scope covers accessible, visible portions, while excluding chimney and flue interiors and several kinds of testing. A neat hearth isn’t evidence that those hidden areas have been evaluated.

Who can check it: A qualified chimney professional who can explain the inspection level, whether an interior scan is appropriate and what remains out of view. A gas fireplace may call for a qualified appliance service professional as well.