- REI-PE here means Residential Energy Inspector/Plans Examiner, an International Code Council (ICC) certification tied to ICC examination 79.
- The exam has 50 four-option, single-answer questions in two hours, and it is open book.
- A scaled score of 75 is required, which is not necessarily 75% raw accuracy.
- Exam 79 is listed in both 2021 and 2024 code editions, so buy and study for the matching one.
Spelling Out the Acronym
The letters stand for Residential Energy Inspector/Plans Examiner. Two job functions are packed into that title. An energy inspector verifies in the field that a home's insulation, air sealing, windows, ducts and mechanical equipment match what the energy code requires. A plans examiner does the paper version of the same job, reading construction documents before a permit is issued to confirm the design will comply once built.
On this site, "REI-PE" refers only to that residential energy credential. The acronym is a batch label used here for convenience: it is not asserted to be ICC's official exam code. ICC's own designation for the underlying test is examination 79 - Residential Energy Inspector/Plans Examiner. If you are searching for a certificate called by those four letters, make sure the page you land on describes residential energy code enforcement, not an unrelated field. For other phrasings of the same question, see our explainers on what REI-PE stands for and what REI-PE certification is.
Who Issues It and What It Verifies
The International Code Council is the issuer. ICC publishes the International Energy Conservation Code (IECC), the model code that most U.S. jurisdictions adopt, sometimes with local amendments, to govern energy efficiency in buildings. The exam-79 credential signals that a person can read and apply the residential portions of that code.
That framing matters for understanding the credential's purpose. It is not a general green-building badge or a sales designation. It is a code-knowledge certification aimed at people who review plans, inspect work in progress, or verify compliance on completed homes. The broader overview lives in our What Is REI-PE? article, and the full picture of the credential is on the REI-PE certification page.
What the Credential Actually Covers
ICC's published preparation material for the 2024 edition organizes the content into six topic areas. These are unweighted preparation topics, not an official blueprint with percentage allocations, so treat them as a map of what to learn rather than a guide to how many questions each will get. Here they are, with what a candidate should expect to master.
Domain 1: History and future of energy codes
Context for why the IECC exists and how it evolves from one edition to the next.
- How successive code editions tightened requirements
- Why code cycles matter when a jurisdiction adopts a specific edition
Domain 2: Administration and documentation requirements
The procedural side of enforcement: what an applicant must submit and what a reviewer must confirm.
- Scope and applicability of the residential provisions
- Construction documents and the information they must show
- Inspection responsibilities and what must be verified on site
Domain 3: Compliance options
The IECC lets builders demonstrate compliance through more than one route, and examiners need to recognize each.
- Prescriptive paths versus performance-based paths
- When a project can trade one measure against another
Domain 4: Specific thermal envelope and systems provisions
The technical core. This is where inspectors spend most field time and where plan reviewers hunt for errors.
- Insulation levels, fenestration performance and air leakage requirements
- Duct and mechanical system provisions
- Reading tables and notes accurately, since small footnotes change requirements
Domain 5: How the IECC relates to existing buildings
Alterations, additions and changes of occupancy follow their own logic and rarely demand that the whole building be brought up to new-construction standards.
- Which work triggers which requirements
- Exceptions that apply to existing construction
Domain 6: Expanded appendices of the 2024 IECC
Material in appendices that jurisdictions may or may not adopt, which makes knowing what is optional versus mandatory part of the skill.
- Locating appendix content in the code book quickly
- Recognizing when an appendix applies only if locally adopted
For a deeper dive into each content area, read REI-PE Exam Domains 2026: Complete Guide to All 6 Content Areas.
What the Exam Looks Like
Exam 79 is a 50-question, two-hour test. Every question is multiple choice with four options and a single correct answer. There is no partial credit and no multi-select format to decode, so the challenge is application and speed, not trick formatting.
Two features shape how candidates should prepare:
- It is open book. You will be looking things up, which means the skill being tested is navigation and interpretation, not memorization. Reference restrictions are published by ICC, and the approved reference list must be checked for the specific edition you test on.
- Delivery is remote-proctored. ICC's IECC/HERS Compliance Specialists page verifies PRONTO remote-proctored delivery for this format. No additional exam-79 testing provider is asserted here.
With two hours for 50 questions, you have a bit over two minutes per item on average. That sounds generous until you meet a question that requires cross-referencing a table, a footnote and a definition. Candidates who tab their books ahead of time finish comfortably; those who search page by page do not. For perspective on difficulty, see How Hard Is the REI-PE Exam?
Key Takeaway
Because the exam is open book, practice looking things up under a clock. Knowing where an answer lives in the code book is worth more than recalling it from memory.
Why the Code Edition Changes Everything
ICC's current national exam list, updated January 12, 2026, lists exam 79 in both the 2021 and 2024 code editions. Neither is silently preferred here. The edition you purchase determines which code book you may bring and which provisions the questions are drawn from.
This is the most common trap for new candidates. Study materials written for one IECC edition can contain requirements that differ from the other, and an answer that is correct under one edition may be wrong under the other. Before you buy a study aid or an approved reference, confirm that it matches the edition on your exam purchase. The six-topic outline above comes from ICC's 2024 IECC preparation course material and should not be read as a verified outline for the 2021 edition.
If you are weighing the formal passing standard, our passing score article explains the scaled-score approach in more detail.
Fees, Purchase Rules and Renewal
| Item | What is verified |
|---|---|
| Exam fee shown on ICC's product page | US$320 |
| Member vs. non-member exam pricing | Not verified; no member discount is claimed |
| Format | 50 questions, two hours, four-option single-answer |
| Use window after purchase | Must be used within 365 days |
| Refunds and transfers | Non-refundable and non-transferable |
| Passing standard | Scaled score of 75 |
| Renewal cycle | Three years |
| Renewal requirement | 1.5 CEUs, including at least 0.8 qualifying Part 1 CEUs |
| Renewal fee | $105 member / $130 non-member |
A few practical consequences follow. Because the purchase is non-refundable and non-transferable, confirm your edition choice before paying. Because the 365-day clock starts at purchase, buy when you are within a few months of being ready, not as an aspirational commitment. And because renewal fees are separate from exam fees, budget for the long term, not just the first test.
ICC also sells a separate conference training-plus-exam package priced at $500. That bundle is distinct from the standalone exam fee, so do not compare the two numbers as if they bought the same thing. For a full pricing picture, see REI-PE Certification Cost 2026.
Who Uses the Credential
The credential is built for the people who enforce or verify residential energy code compliance. In practice that tends to mean:
- Municipal and county building departments that employ plans examiners and field inspectors, and that may value or require ICC certifications for those roles.
- Third-party plan review and inspection firms that contract with jurisdictions or builders.
- HERS Raters and energy-efficiency consultants who want to add code-compliance verification to their service line.
- Builders and contractors who want an internal expert to catch compliance problems before an inspector does.
No exam-79-specific salary estimate or demonstrated certification earnings premium was verified, so this article makes no earnings claim. If you are weighing career value, our ROI analysis, salary guide and REI-PE jobs overview discuss the question in context. Also, no exam-79-specific education or experience minimum was verified in accessible ICC material; our requirements article covers what is and is not established.
Scheduling Study Time by Domain
One short note on sequencing. Because this is an open-book exam, order your preparation around the code book itself. Start with the structural domains so you learn the layout of the book, then move into the dense technical material when you can already navigate it.
Orientation and administration
- Cover Domains 1 and 2: code history, scope, documentation and inspection duties
- Tab the administrative chapters and definitions of your purchased edition
Compliance paths
- Work Domain 3 until you can tell prescriptive from performance routes at a glance
Envelope and systems
- Spend the most time on Domain 4; practice reading tables and footnotes under a clock
Existing buildings and appendices
- Finish Domains 5 and 6, then take timed mixed practice sets
The reasoning: Domain 4 is where look-up speed pays off most, so you want the book already tabbed and familiar before you reach it. For a broader plan, see the REI-PE study guide and keep the cheat sheet handy for last-week review. When you are ready to test yourself, try the REI-PE practice tests.
What Cannot Be Claimed
Honest preparation means knowing where the public information stops. Several things candidates often ask about are not established:
- A population pass rate. ICC's marketing claim of up to 90% for course participants is not a pass rate for all candidates. See what the data shows.
- Current exam weights. The edition-specific formal blueprint could not be verified. A historical ICC-authored 2021 presentation listed percentage allocations for an older four-part outline, but those are not the current 2024 weights and are not applied here.
- Exact test dates. Scheduling mechanics are covered in the exam dates article.
The takeaway: treat the six domains as a study map, not a scoring formula, and always cross-check against ICC's current published materials. You can also revisit the plain-language definitions at REI-PE meaning, what is a REI-PE and what does REI-PE mean, and see the training options overview if you want structured instruction.
Frequently Asked Questions
On this site it means Residential Energy Inspector/Plans Examiner, an ICC certification corresponding to examination 79. It covers inspecting residential construction and reviewing plans for energy code compliance.
The International Code Council, the organization that publishes the IECC and administers its own credentialing program for code professionals.
There are 50 multiple-choice questions with four options each and one correct answer, delivered in two hours. The exam is open book, but approved references are restricted, so check ICC's published list for your edition.
ICC requires a scaled score of 75. That is not necessarily 75% raw accuracy, so do not assume you can miss a fixed number of questions.
ICC's renewal bulletin describes a three-year cycle requiring 1.5 CEUs, including at least 0.8 qualifying Part 1 CEUs, with a renewal fee of $105 for members or $130 for non-members, separate from exam fees.