Is thermal imaging worth it for home inspectors?

A thermal camera, also called an infrared camera, reads surface temperature and shows it as a color map. It does not see through anything solid. Teledyne FLIR says it plainly in its guide to whether thermal imaging can see through walls. The camera detects heat from the wall, not what is behind it. Glass and polished metal act like mirrors for infrared, so the camera shows a reflection there.

What it can do is flag patterns worth a closer look:

• Possible moisture, which often shows as cooler areas on walls and ceilings
• Missing or settled insulation in attics and walls
• Warm electrical connections at panels, outlets, and other parts
• Uneven air flow at supply and return vents
• Air leaks through the building envelope

A freshly painted wall can look dry and still show a pattern worth checking. That is the reason to own one. Each of those patterns is a lead, not a finding, until a moisture meter or another test confirms it.

Infrared works on temperature difference, called Delta T. With too little of it, missing insulation and air leaks barely show. Fluke, which makes thermal cameras, gives these points in its thermal imaging inspection checklist:

• At least 18 degrees F (10 degrees C) between interior and exterior surfaces, though some scans can work with less
• A stable difference for at least four hours, where possible
• Record wind speed and direction, sun position, and rain

Fluke also notes that damp areas change temperature more slowly than dry ones. That is why a wet spot can stand out as the house warms or cools. On a mild day, the camera may show very little.

No major standard requires the camera. Under the InterNACHI Standards of Practice, the inspector need not operate "moisture meters, gas detectors or similar equipment." The 2014 ASHI Standard does not mention infrared at all. ASHI's revised Standard, approved in January 2026 and not yet in force, lets an inspector use reasonable tools. It lists thermal imaging equipment among the specialized equipment an inspector is not required to use.

So a thermal scan is work beyond the standard. That is what lets an inspector sell it as an add-on or use it to set the inspection apart. For how the two standards compare, see home inspection standards of practice.

An image read wrong does harm two ways. It can alarm a client over nothing, or it can hide a real problem the inspector did not recognize. Two common routes:

Before charging for scans, learn these:

• Delta T and when conditions are good enough to scan
• Reflective surfaces and other false readings
• How sun, wind, and the HVAC system change the picture
• Confirming a suspected wet area with a moisture meter

Most of the price difference between cameras is thermal resolution and sensitivity. Fluke's checklist cites minimums proposed by the Residential Energy Services Network (RESNET) for building work. They call for infrared resolution of at least 120 by 120 and thermal sensitivity of 100 mK or better. The field of view should be about 20 degrees or more. Use those as a floor, and check prices on the maker's own page, since they change.

There are two ways to use it. As an add-on, thermal imaging brings in its own fee. Included on every job, it becomes part of what sets the inspection apart. Either can work. The choice comes down to how an inspector wants to position the business, and in both cases the training pays off on every house.

For other services that raise what an appointment earns, see which add-on services pay. For narrower lines of work, see home inspector specializations that pay.