Radon, Sewer, Termite, and Mold Inspection Costs (2026)
Published 2026-06-17 · Updated 2026-07-08
The general inspection does not cover everything. Four add-ons handle what it misses: radon runs $100 to $200, a sewer scope is $150 to $300, termite inspection is $75 to $150, and mold testing runs $300 to $700. Which ones you actually need depends on the home's age, location, and what the general inspector flags along the way.
Our 2026 cost reference shows the general inspection running $420 to $630 on a 1,500 to 2,500 square foot newer home once radon, mold, or termite testing gets bundled in, versus $300 to $450 with no add-on at all. Use the calculator to see your own number before you call around.
Radon inspection cost
Radon is a naturally occurring radioactive gas that seeps through foundation cracks and is the second-leading cause of lung cancer in the United States. Professional testing costs $100 to $200 when added to a home inspection. A DIY mail-in kit from a hardware store runs $25 to $50 if you want to test independently. Professional testing uses a continuous electronic monitor or charcoal canister placed in the lowest livable area of the home for 48 hours.
If results come back at or above 4 picocuries per liter, the EPA's recommended action level per its radon guidance last updated November 12, 2025, mitigation is recommended. A radon mitigation system costs $800 to $2,500 depending on foundation type. Radon is most prevalent in the upper Midwest, Mid-Atlantic, and mountain states, but no region has a clean bill of health.
Should I always get a radon test?
Yes, if you are buying a home with a basement or in a moderate-to-high radon zone. The test costs $100 to $200. A mitigation system, if you need one, runs $800 to $2,500. That math makes testing one of the better-value add-ons you can order. The EPA recommends testing all homes below the third floor. Ask your inspector what the radon picture looks like in your specific area.
Sewer scope inspection cost
A sewer scope pushes a camera through the main drain line from the house to the municipal connection. It shows root intrusion, pipe collapse, offset joints, and blockages that would be expensive surprises after purchase. The inspection costs $150 to $300 and takes 30 to 60 minutes.
Sewer line repairs run $1,500 for a spot fix to $15,000 or more for a full replacement. That makes the $200 scope fee look small. The test is most valuable for homes built before 1980, when clay and cast-iron pipe was standard, and for properties with large mature trees near the drain line path.
Is a sewer scope worth it?
For homes more than 30 years old or with large mature trees near the property line, yes. Sewer line replacement regularly runs $8,000 to $20,000. The scope costs $150 to $300. That is a simple calculation. Finding a compromised line before closing gives you a repair credit to negotiate or a reason to walk, rather than an ugly bill you inherit after the keys change hands.
Termite and pest inspection cost
A termite or wood-destroying organism (WDO) inspection costs $75 to $150 in most markets. The inspector looks for active infestations, past damage, wood rot, carpenter ants, and other organisms that compromise structural wood. For VA loans, a termite inspection is required in many states, and the seller may be required to cover it.
Treatment costs vary: spot treatments run $300 to $700, and whole-home tent fumigation runs $1,200 to $3,000. Structural repairs from long-term infestations can add thousands on top of that. At $75 to $150, the termite inspection is one of the cheapest add-ons that reliably earns its cost in termite-prone regions.
Mold inspection cost
A mold inspection costs $300 to $700 for a visual assessment plus air sampling. Lab testing of collected samples can push the total past $1,000. Mold inspections are not part of a standard home inspection, but your general inspector will flag visible mold growth or moisture conditions that suggest a closer look is warranted.
Professional mold remediation runs $500 to $6,000 depending on scope, which makes a pre-purchase mold inspection a sensible call for homes with water damage history, a persistent musty smell, or any evidence of past flooding. Mold that has been painted over is not the same as mold that has been remediated.
Other specialty inspections to consider
| Inspection type | Cost range | When to consider it |
|---|---|---|
| Chimney inspection | $100 to $250 | Home has a fireplace or wood stove |
| Pool and spa inspection | $100 to $300 | Property has a pool or hot tub |
| Well water test | $100 to $400 | Home uses a private well |
| Septic inspection | $250 to $600 | Home has a septic system |
| Asbestos testing | $250 to $800 | Home built before 1980 with suspect materials |
| Lead paint test | $250 to $400 | Home built before 1978 |
FAQs
Can I bundle these tests to save money?
Usually. Many inspection companies will run radon or a sewer scope alongside the general visit for less than booking them separately, since the inspector is already on site.
Which add-ons matter most?
Radon, a sewer scope on anything over 30 years old, and termite testing in termite country cover most buyers' real risk. Past that, let the home's age, location, and whatever the general inspector flags guide the rest.
What to actually budget for
Radon, a sewer scope on older homes, and termite testing in the right regions are the three add-ons most buyers should price in before making an offer. Mold, asbestos, well, and septic testing are situational: order them only when the home's age, location, or visible condition points that way. Get quotes early and price out the base inspection plus whichever add-ons apply using the calculator up top.
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