- CETI stands for Council-certified Environmental Thermography Investigator, issued through the American Council for Accredited Certification (ACAC) and...
- Initial cost is $500 for US/Canada applicants: a $100 examination fee plus a $400 certification fee.
- The exam is closed-book, computer-delivered multiple choice, with a passing threshold of at least 75%.
- Applicants submit four separate project sheets and verifiable investigation reports or contracts; certification requires unanimous board approval.
What a CETI Actually Is
Key Takeaways
- CETI stands for Council-certified Environmental Thermography Investigator, issued through the American Council for Accredited Certification (ACAC) and CESB-accredited.
- Initial cost is $500 for US/Canada applicants: a $100 examination fee plus a $400 certification fee.
- The exam is closed-book, computer-delivered multiple choice, with a passing threshold of at least 75%.
- Applicants submit four separate project sheets and verifiable investigation reports or contracts; certification requires unanimous board approval.
- Certification lasts two years, and the renewal requirements in ACAC's materials contain a discrepancy you should confirm directly.
A CETI is a professional who has earned the Council-certified Environmental Thermography Investigator credential. In plain terms, it identifies someone who uses infrared thermography to investigate buildings and building systems, and who has had that competence reviewed by an accredited certifying body rather than simply claiming it. If you have seen the acronym attached to other certifications, set those aside: this article covers only the ACAC thermography credential. For a shorter definition, see our companion explainer, What Is CETI?, and for the wording of the title itself, What Does CETI Stand For?.
The word "investigator" is deliberate. The credential is not about owning an infrared camera. It is about interpreting what thermal patterns mean, tying those patterns to physical causes such as moisture, missing insulation or failing plumbing, and documenting findings in a way that holds up in a report or a dispute.
Who Issues the Credential and Why That Matters
The CETI is awarded by the American Council for Accredited Certification (ACAC), and the credential is CESB-accredited. That accreditation is the part buyers of inspection services and employers tend to care about, because it signals that the certification process itself has been evaluated against a recognized standard, not just that a training vendor handed out a certificate.
ACAC administers its examinations through Kryterion, the testing provider. Delivery is either at a test center or through secure online video proctoring, so candidates are not forced to travel if a remote option suits them better.
Because the credential is niche, the official sources carry unusual weight. The ACAC thermography page, the candidate handbook, the application process page and the Official CETI Application are the primary references. Anything a third party tells you, including this article, should be checked against them before you commit money or time.
What a CETI Does on a Job Site
Thermography converts surface temperature differences into images. A building envelope or plumbing system that looks uniform to the eye can show distinct thermal signatures when moisture is trapped, insulation is absent or compressed, air is leaking, or a pipe is leaking behind a finished surface. A CETI is expected to recognize those signatures and distinguish them from harmless thermal noise.
ACAC's competency description also covers the underlying science and equipment: thermal and infrared physics and infrared-camera selection, calibration and operation. In practice that means a certified investigator should be able to explain why a reading can mislead (emissivity, reflections, ambient conditions, timing), choose appropriate equipment for a job, and operate it correctly rather than treating the camera as a point-and-shoot device.
Investigation, not just imaging
The distinction between taking pictures and conducting an investigation runs through the whole credential. The application itself asks for verifiable investigation reports or contracts and four project sheets, which reflects an expectation that candidates have actually diagnosed problems in the field and written about them. Our article on CETI certification expands on how the credential fits into a professional practice.
The Four Competency Areas
ACAC's materials list four application competencies. They are presented without weights, and ACAC has not published a complete exam blueprint or an official total domain count, so treat these four headings as the confirmed scope rather than an exhaustive syllabus. For a deeper walk-through, read CETI Exam Domains 2026: Complete Guide to All 4 Content Areas.
Domain 1: Roof Inspections
Roofs are where water enters buildings, and thermography is widely used to locate wet insulation and membrane problems without destructive testing.
- How solar loading and cooling cycles reveal moisture retained in roofing assemblies
- Choosing the time of day and weather conditions that make findings reliable
- Separating genuine moisture anomalies from thermal effects caused by roof layout, ponding or surface variation
Domain 2: Building Exterior Investigations
The exterior envelope controls heat flow, air movement and water intrusion at walls, openings and transitions.
- Interpreting thermal patterns at walls, windows, doors and penetrations
- Recognizing the influence of sun, wind and temperature differential on what the camera shows
- Documenting exterior findings so the cause and location are clear to a reader who was not on site
Domain 3: Building Interior Investigations
Interior work targets concealed conditions behind finished surfaces, where problems are invisible until damage appears.
- Identifying insulation gaps, air leakage paths and moisture in walls and ceilings
- Controlling interior conditions to create a usable temperature difference
- Confirming thermal findings with corroborating evidence rather than relying on an image alone
Domain 4: Plumbing Investigations
Leaks and failing lines often leave thermal fingerprints long before visible staining.
- Spotting supply-line, drain and radiant-heating anomalies through thermal contrast
- Understanding how water temperature and flow affect detectability
- Relating a thermal pattern to a plausible plumbing cause and recommending follow-up verification
Across all four areas, the cross-cutting skill is the same: connect the thermal image to a physical explanation. That is why the infrared physics and camera-operation competencies matter even though they are not one of the four named headings.
Exam Format and Delivery
ACAC's general examination policy describes the testing format, and it is worth knowing before you sit down:
- Closed-book. No reference materials during the exam, so concepts and relationships need to live in your head.
- Computer-delivered multiple choice with at least four answer choices per question.
- Test center or secure online video proctoring through Kryterion, giving you a choice of setting.
- Passing threshold of at least 75%, verified in the current Official CETI Application.
The specifics of the passing score and how it is applied are covered in CETI Passing Score 2026. For a candid look at difficulty, including why a niche, application-heavy credential feels different from a broad survey exam, see How Hard Is the CETI Exam?. And because ACAC has not released pass-rate data in the sources checked, our CETI pass rate article explains what can and cannot be said.
Eligibility and the Application Package
Unlike credentials you can pursue straight from a classroom, the CETI is gated by documented experience. The core requirement is two combined years of relevant science-related postsecondary education and field experience. ACAC's eligibility FAQ adds an important floor: at least one actual year of field experience, so education alone cannot cover the full requirement.
The application package is substantial:
- Transcripts when you claim education toward the requirement.
- Verifiable investigation reports or contracts for relevant investigations, consulting or report writing.
- Four separate project sheets describing your investigation work.
- The online application and email verifications.
There is no mandatory training course. You do not need to complete a specific class to qualify, though a candidate with thin field exposure in one of the four areas will want to fill that gap by whatever means works. Our CETI requirements guide walks through how to document experience, and CETI training covers options for building skills if you have gaps.
Key Takeaway
Start assembling your project sheets and verifiable reports before you think about the exam. Documentation is the slowest part of the process, and because certification requires unanimous board approval, incomplete or unverifiable evidence is a more realistic obstacle than the test itself.
Fees, Timeline and Renewal
| Item | Amount / Rule |
|---|---|
| Examination fee | $100 |
| Certification fee | $400 |
| Initial total (US/Canada) | $500 |
| Initial total (outside US/Canada, per official application) | $525 |
| Retake | $100 |
| Renewal | $400 |
| Certification validity | Two years |
| Time to complete application and exam | Within six months |
Plan your calendar around the six-month window: the whole application process, including the examination, must be finished in that time. Starting the exam scheduling late, after a long documentation phase, is a classic way to run short. See CETI exam dates for scheduling considerations, and CETI certification cost for a fuller budget view including how a retake factors in.
Renewal: confirm before you plan
Certification is valid for two years. ACAC's central renewal procedure calls for 40 renewal credits (RCs), made up of 10 for continued field activity and 30 hours of professional development. However, the credential page describes 20 professional-development hours annually. These descriptions do not obviously match, so contact ACAC to confirm which applies to you before you build a renewal plan around either one.
Who Uses a CETI
The credential is aimed at people whose work depends on diagnosing building conditions: independent thermography consultants, building and property inspectors adding infrared services, roofing and envelope specialists, moisture and mold assessors, and consultants who write reports that others rely on in repair or dispute decisions. The documentation-heavy application also suggests the credential is oriented toward people whose findings may be scrutinized.
Because ACAC's sources give no salary data, any specific compensation figure would be invented, so this article does not offer one. For a qualitative discussion of how the credential relates to earning potential, read CETI salary guide, and for a framework to weigh the investment, Is the CETI certification worth it?. If you are exploring roles, CETI jobs covers where the credential tends to matter.
Sequencing Your Preparation
Since the four domains are unweighted in ACAC's materials, there is no official basis for spending more time on one than another. A sensible approach is to sequence by your own gaps and by how the topics build on each other. Thermal physics and camera operation underpin everything, so they come first; the building-specific domains then apply them.
Physics and equipment
- Infrared physics, emissivity and reflection
- Camera selection, calibration and operation
Roofs and exteriors
- Domain 1 and Domain 2 together, since both depend on solar loading and weather conditions
Interiors and plumbing
- Domain 3 and Domain 4, where controlling conditions and corroborating findings matter most
Scenario practice
- Timed multiple-choice sets across all four domains
For a complete method, see the CETI study guide, and for a fast refresher near exam day, the CETI cheat sheet. Candidates who want to check readiness can try the free questions on the main CETI practice test site. If you are still sorting out terminology, our pages on CETI meaning and what CETI certification is cover the basics.
Frequently Asked Questions
Here it stands for Council-certified Environmental Thermography Investigator, a credential issued through the American Council for Accredited Certification (ACAC). Other credentials use the same acronym, so always confirm the certifying body.
For US and Canada applicants, the initial total is $500: a $100 examination fee plus a $400 certification fee. The official application lists $525 for applicants outside the US/Canada. A retake is $100 and renewal is $400.
The passing threshold is at least 75%, verified in the current Official CETI Application. The exam is closed-book, computer-delivered multiple choice with at least four answer choices per question.
No. There is no mandatory training course. You must instead meet the eligibility requirement of two combined years of relevant education and field experience, including at least one actual year of field experience, and submit four project sheets plus verifiable reports.
It is valid for two years. The renewal procedure lists 40 RCs (10 for field activity, 30 hours of professional development), while the credential page describes 20 professional-development hours annually. Confirm the current requirement with ACAC before planning.