- What CETI Spells Out
- Reading the Title Word by Word
- Who Issues the Credential
- The Four Application Competencies
- What a CETI Holder Actually Does
- How the Credential Is Earned
- Fees, Validity and Renewal
- Why the Acronym Causes Confusion
- Who Hires and Who Benefits
- Planning Preparation Around the Domains
- Frequently Asked Questions
- CETI means Council-certified Environmental Thermography Investigator, issued by the American Council for Accredited Certification (ACAC).
- The four listed competencies are roof, building exterior, building interior and plumbing investigations.
- Initial cost is $500 for US/Canada applicants: a $100 examination fee plus a $400 certification fee.
- Passing requires at least 75% on a closed-book, computer-delivered multiple-choice exam delivered through Kryterion.
What CETI Spells Out
CETI stands for Council-certified Environmental Thermography Investigator. It is a professional credential tied to the practice of using infrared thermography to investigate conditions in and around buildings. The title is awarded by the American Council for Accredited Certification (ACAC), and the program is CESB-accredited.
If you landed here searching for the meaning of the acronym, the short answer is that it names a person, not a device or a method: the "investigator" is the certified professional, and "environmental thermography" is the discipline they apply. For related phrasing of the same question, see our explainers on what CETI stands for, what CETI means and what a CETI is.
Reading the Title Word by Word
Each word in the credential name carries meaning, and understanding them helps you understand what the exam is probing.
Council-certified
The certification comes from a council, ACAC, rather than from an equipment maker or a training vendor. That distinction matters: the credential is built around demonstrated education, verifiable field experience and a board decision, not just attendance at a class. ACAC does not mandate any particular training course as a prerequisite.
Environmental
"Environmental" here points at the built environment: the building envelope, its interior surfaces and its water-carrying systems. The four application competencies reflect this, covering roofs, exteriors, interiors and plumbing rather than electrical or mechanical industrial equipment.
Thermography
Thermography is the measurement and visualization of surface temperature patterns, typically with an infrared camera. ACAC's materials also describe thermal and infrared physics along with infrared-camera selection, calibration and operation, so a holder is expected to understand the instrument and the physics behind the image, not just point and shoot.
Investigator
The final word signals the purpose. A CETI holder is expected to investigate: to gather evidence, interpret thermal patterns in context, and document findings in a defensible way. That is why the application leans on verifiable investigation reports and project sheets rather than only coursework.
Who Issues the Credential
ACAC administers the program under UID cc-de2eca0570e6. Examinations are delivered through the testing provider Kryterion, either at test centers or through secure online video proctoring. ACAC's general examination policy describes closed-book, computer-delivered multiple-choice testing with at least four answer choices per question.
Certification also requires unanimous board approval, which makes it more than a score-and-done credential. Your application materials are reviewed as a package. ACAC's December 31, 2025 activity report lists three current CETI certifications. That figure counts current holders, not exam volume, and it tells you the community of certified investigators is small. For anyone weighing the career angle, our ROI analysis of the CETI certification and CETI jobs overview put that into context.
The Four Application Competencies
ACAC's published competency page lists four areas. These reproduce the issuer's listed application competencies; they are unweighted and should not be read as a complete exam blueprint or a statement of the official number of exam domains. ACAC has not supplied a full syllabus, and the linked candidate handbook page contains no syllabus text. For a deeper walk through each area, see our complete guide to the four CETI content areas.
Domain 1: Roof inspections
Roofs are a classic thermography subject because moisture trapped in roofing assemblies holds and releases heat differently from dry material.
- Recognizing thermal patterns that can indicate wet insulation or membrane problems
- Understanding how time of day, weather and solar loading affect what the camera shows
- Distinguishing true anomalies from surface effects such as reflectance and shading
Domain 2: Building exterior investigations
Exterior work looks at walls, cladding, openings and the interface between the envelope and the outdoors.
- Identifying air leakage and insulation gaps through the envelope
- Accounting for temperature differential, wind and sun exposure during the scan
- Documenting findings with paired thermal and visible-light images
Domain 3: Building interior investigations
Interior investigations focus on walls, ceilings, floors and assemblies where moisture, missing insulation or air movement may hide.
- Interpreting thermal signatures that suggest moisture intrusion
- Understanding how emissivity and surface finishes change apparent temperature
- Correlating thermal findings with confirmatory methods rather than treating the image as proof alone
Domain 4: Plumbing investigations
Plumbing work uses temperature differences to trace supply lines, detect leaks and find concealed water paths.
- Reading thermal evidence of hot and cold water lines behind finishes
- Separating active leaks from historic staining or ambient effects
- Reporting findings clearly enough for a plumber, owner or insurer to act on
Beyond these four headings, ACAC's materials also describe thermal and infrared physics and infrared-camera selection, calibration and operation. Expect the instrument fundamentals to underpin every domain. Because there is no weighted blueprint, treat all four areas as equally important until ACAC publishes more.
What a CETI Holder Actually Does
In practice, a Council-certified Environmental Thermography Investigator is someone who is hired to answer a question about a building: Where is the moisture coming from? Is the roof insulation wet? Why is this wall cold? Is that stain an active leak? The deliverable is usually a report that pairs thermal images with visible-light images, explains the conditions under which they were captured, and states conclusions with appropriate caution.
Because thermal images can mislead when conditions are wrong or interpretation is rushed, a core professional skill is knowing the limits of the technique. A good investigator states what the camera can and cannot establish, and recommends follow-up verification where warranted.
How the Credential Is Earned
The route to certification has several parts, all of which must be completed within six months, including the examination. The details live in our CETI requirements guide, but the essentials are:
- Establish eligibility. You need two combined years of relevant science-related postsecondary education and field experience. ACAC's eligibility FAQ requires at least one actual year of field experience.
- Document your background. Provide transcripts when claiming education, and verifiable investigation reports or contracts for relevant investigations, consulting or report writing.
- Submit the application package. This includes the online application, four separate project sheets and email verifications.
- Sit the exam. Closed-book, computer-delivered, multiple-choice, through Kryterion at a test center or by secure online proctoring. The threshold is at least 75%, as verified in the current Official CETI Application. See our CETI passing score breakdown.
- Receive board approval. Certification requires unanimous board approval.
No training course is mandatory. That said, if you are looking for structured learning to fill knowledge gaps, our CETI training overview covers options, and the CETI study guide lays out a preparation plan.
Fees, Validity and Renewal
| Item | Detail |
|---|---|
| Examination fee | $100 |
| Certification fee | $400 |
| Initial total (US/Canada) | $500 |
| Initial total (outside US/Canada) | $525, as listed on the official application |
| Retake fee | $100 |
| Renewal fee | $400 |
| Validity period | Two years |
For a fuller treatment of what you will spend and when, read the CETI certification cost breakdown.
Renewal requirements and a discrepancy to check
ACAC's central renewal procedure calls for 40 recertification credits (RCs) per two-year cycle: 10 for continued field activity and 30 hours of professional development. However, the credential page describes 20 professional-development hours annually, which is not obviously the same arithmetic. If you are planning your renewal, confirm the exact requirement directly with ACAC before you commit to a plan.
Key Takeaway
Keep a running log of field investigations and professional development from the day you are certified. Whichever renewal formulation ACAC confirms, you will need documentation, and reconstructing two years of activity at the deadline is far harder than recording it as you go.
Why the Acronym Causes Confusion
The four letters C-E-T-I are used by more than one credential and organization, which is why a plain search for "CETI" can return unrelated material. The ACAC credential is specifically the Council-certified Environmental Thermography Investigator. When you compare sources, check three things before trusting any number or rule:
- The issuing body. It should be ACAC, the American Council for Accredited Certification.
- The subject matter. It should concern thermography applied to buildings: roofs, exteriors, interiors and plumbing.
- The testing provider. It should be Kryterion, with the $100 examination and $400 certification fees.
If a page quotes different fees, a different certifying organization or unrelated subject matter, it is describing something else. For more definitional pages on this exact credential, see What Is CETI?, What Is CETI Certification? and the main CETI certification page.
Who Hires and Who Benefits
Because the four competencies center on building conditions, the natural audience is people who investigate or advise on buildings. Without inventing figures, it is reasonable to describe the types of roles where thermography credentials are relevant:
- Independent thermography and building-diagnostics consultants who need a recognized credential to support their reports.
- Building and property inspectors who want to add a defensible thermal service to their offering.
- Moisture, restoration and forensic investigators who trace water intrusion and need documented methodology.
- Envelope and roofing consultants who evaluate insulation, air leakage and membrane condition.
Earnings vary widely with market, specialization and whether you work independently or for an employer, and we do not cite figures that ACAC does not publish. For a qualitative look at the economics, see our CETI salary guide. Because the certified population is small, the credential tends to function as a differentiator rather than a mass-market baseline.
Planning Preparation Around the Domains
Since the exam has no published weighting, a balanced plan is the safest approach. One sensible sequencing, tied directly to the four competencies:
Physics and the instrument
- Thermal and infrared physics, emissivity and reflected temperature
- Camera selection, calibration and operation
- Why this comes first: every domain depends on it
Roofs and exteriors
- Roof inspections and building exterior investigations together
- Weather, solar loading and temperature differential effects
- Why they pair: both are outdoor, condition-dependent scans
Interiors and plumbing
- Building interior investigations and plumbing investigations together
- Moisture signatures, concealed leaks and confirmation methods
- Why they pair: both revolve around hidden water and indoor interpretation
Practice under exam conditions
- Closed-book multiple-choice questions across all four domains
- Review misses by domain to find weak spots
For the exam-day side of this, our guide on how hard the CETI exam is discusses what to expect, and the CETI cheat sheet condenses the key facts. When you are ready to test yourself, try the CETI practice tests to find which domain needs more attention. Scheduling logistics are covered in our exam dates guide, and what is known about outcomes is in the CETI pass rate article.
Frequently Asked Questions
In this context, CETI stands for Council-certified Environmental Thermography Investigator, a credential issued by the American Council for Accredited Certification (ACAC) and accredited by CESB.
ACAC lists four application competencies: roof inspections, building exterior investigations, building interior investigations and plumbing investigations. Its materials also describe thermal and infrared physics and infrared-camera selection, calibration and operation. These headings are unweighted and are not a complete exam blueprint.
For US/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 costs $100 and renewal costs $400.
The passing threshold is at least 75%, as verified in the current Official CETI Application. The exam is closed-book, computer-delivered and multiple-choice, with at least four answer choices per question.
It is valid for two years. ACAC's central renewal procedure requires 40 RCs, made up of 10 for continued field activity and 30 hours of professional development, though the credential page describes 20 professional-development hours annually. Confirm the exact requirement with ACAC when planning renewal.