ICC B1 vs B2 vs R5: which inspector exam?
✓ Checked 20 Oct 2026 against ICC's exam store listings, content outlines, national exam list and combination designations page, and against state rules in Kentucky, Rhode Island, New Jersey and Utah.
"ICC building inspector certification" can mean three different things. B1 is the Residential Building Inspector exam. B2 is the Commercial Building Inspector exam. R5 is not an exam at all: it is a designation ICC grants once you hold four residential certifications, B1, E1, M1 and P1. Which one you need depends on the buildings you will inspect and on the rule your state or employer applies, so this page compares all three and shows what four state rules actually name.
The short answer
- Inspecting one- and two-family homes and townhouses: B1 is the usual starting exam. The Kentucky, Rhode Island and New Jersey rules below all name it for their residential level.
- Inspecting commercial buildings: B2 covers commercial structures of any size or occupancy. Several state rules ask for B1 and B2 together rather than B2 alone.
- Inspecting every trade on residential jobs: R5 means passing B1, E1, M1 and P1. None of the state rules checked here names R5 by code. Utah's rule lists the Residential Combination Inspector certification by name as one option.
B1, B2 and R5 side by side
| B1 | B2 | R5 | |
|---|---|---|---|
| What it is | Single exam | Single exam | Designation built from four exams |
| ICC title | Residential Building Inspector | Commercial Building Inspector | Residential Combination Inspector |
| Scope in ICC's outline | One- and two-family dwellings, townhomes up to three stories, accessory structures | Commercial structures of any size or occupancy | Building, electrical, mechanical and plumbing on residential work |
| Questions | 60 | 80 | 60 per exam, 240 in total |
| Time | 2 hours | 3.5 hours | 2 hours per exam, 8 hours in total |
| Code years offered | 2021 and 2024 | 2021 and 2024 | 2021 and 2024 for each of B1, E1, M1, P1 |
| List price | $320 | $320 | $320 per exam, $1,280 for all four |
✓ Sources: the B1 content outline and B2 content outline give scope, question count and time, and both say open book. The ICC store listings for B1, B2, E1, M1 and P1 each show a $320 price, and the same counts and durations. ICC's national exam list (last update 12 Jan 2026) shows the code years. The R5 totals are our own arithmetic from those listings.
Each store listing says purchases are valid for 365 days. ICC's exam catalog says members get discounted exam pricing, but the store listings showed no member amount on 20 Oct 2026, so this page quotes list prices only. ICC's retake policy says you pay the exam fee at every attempt; the cost and scheduling guide covers ICC's attempt limits.
What R5 actually requires
✓ ICC's combination designations page lists R5 Residential Combination Inspector as requiring all four residential inspector certifications: B1, E1, M1 and P1. The same page says ICC does not treat older model-code inspector certifications as equivalent, and that renewing the individual certifications does not automatically renew the designation.
That page also shows where B1 and B2 lead beyond R5:
| Designation | Certifications it requires |
|---|---|
| B5 Building Inspector | B1 and B2 (ICC says it is granted automatically once you hold both) |
| C5 Commercial Combination Inspector | B2, E2, M2, P2 |
| C8 Combination Inspector | B1, B2, E1, E2, M1, M2, P1, P2 |
| B8 Building Code Specialist | B1, B2, B3, and the Code Specialist module |
So B1 is the shared first step for R5, B5 and C8. If you expect to want a combination designation later, starting with B1 rarely wastes an exam.
How the B1 and B2 outlines differ
Both outlines use the same seven content areas, but the weights shift toward life safety on the commercial exam.
| Content area | B1 weight | B2 weight |
|---|---|---|
| Code or general administration | 4% | 6% |
| Building planning | 8% | 20% |
| Footings and foundations | 16% | 8% |
| Floor construction | 14% | 8% |
| Wall construction and coverings | 27% | 21% |
| Roof and ceiling construction | 14% | 6% |
| Public safety and special construction | 17% | 31% |
✓ Weights from the B1 outline and B2 outline. Note that the B2 outline file carries a 2016 creation date in its metadata and the B1 outline file a 2014 one. Their question counts and times still match the current store listings, but check the catalog entry for your code year before you rely on the weights.
In practice, B1 is a framing exam: walls, foundations, floors and roofs make up 71% of it. B2 puts 51% on building planning plus public safety, which brings occupancy classification, type of construction, fire-resistance-rated construction, fire protection systems and means of egress into play. On B2, means of egress alone is weighted at 10%, more than all of B2's roof and ceiling items. For more on the B1 areas, see the B1 outline guide.
Which code book each exam is built on
ICC's 2024 study guide listings name the references each course needs, which tells you which book to tab:
- B1: the 2024 B1 study guide lists the 2024 International Residential Code.
- B2: the 2024 B2 study guide lists the 2024 International Building Code, ACI 318-19 and the ICC concrete manual for the 2024 and 2021 IBC.
- E1: the 2024 E1 study guide lists the 2024 IRC and the 2023 NFPA National Electrical Code.
- M1 and P1: the 2024 M1 study guide and 2024 P1 study guide each list the 2024 IRC.
These are the study guides' lists, not the exam catalog's reference list, which was not readable without signing in. Confirm the references for your exam and code year in the catalog before you buy books. One practical consequence: B1, M1 and P1 all run on the IRC, so an R5 candidate can use one IRC for three of the four exams and add an NEC for E1. B2 needs a different main book. The 2021 or 2024 IRC guide covers choosing the edition.
Which state rules name which exam
These are the rules we could read today. Each is a starting point; your jurisdiction or employer may add conditions.
| State | Rule | What it names |
|---|---|---|
| Kentucky | 815 KAR 7:070, Section 5 | One- and two-family dwelling inspector: B1 and M1. Building inspector level I: B1, B2 and M1. Level II adds M2. Level III: B1, B3, M1 and M3 |
| Rhode Island | 510-RICR-00-00-11, Section 11.6(B) | Building Inspector-1 (residential): B1, a state class and 3 years of residential construction experience. Building Inspector-2 (residential and commercial): B1 and B2, a state class and 3 years of residential and commercial experience |
| New Jersey | DCA required-exams sheet | Building RCS level: B1 and M1. Building ICS level: B2 and M2. Building HHS level: B3 |
| Utah | R156-56-302(3) | Combination Inspector: the ICC Combination Inspector certification, or building, electrical, plumbing and mechanical certifications. Limited Inspector: any one of a list that includes the Residential Combination Inspector certification |
Kentucky. ✓ The Kentucky legislature's page for 815 KAR 7:070 lists each ICC route alongside an NCPCCI module route. The page also showed that a proposed version of the regulation exists and a history note reading "Crt to Am" with a filing deadline in June 2027, so check the current text before you apply. B1 appears in every building level, and B2 first appears at level I.
Rhode Island. ✓ The Secretary of State's copy of 510-RICR-00-00-11, in the version effective 1 Dec 2025, names ICC B-1 for Building Inspector-1 and B-1 with B-2 for Building Inspector-2. Each route also requires 3 years of experience (residential for Building Inspector-1, residential and commercial for Building Inspector-2) and a state building code class within a year, and the rule lists another route as well. Electrical, mechanical and plumbing inspectors in that rule qualify through state trade licenses and experience, not ICC exams, so R5 does not appear.
New Jersey. ✓ The required-exams sheet linked from DCA's licensing page pairs each building license level with ICC exams: B1 and M1 for RCS (residential and small commercial), B2 and M2 for ICS (industrial and commercial), and B3 for HHS (high-rise and hazardous). It lists E1 and E2 under the electrical ICS level. The exam is one part of a New Jersey license; our certification by state guide covers the agency route.
Utah. The rule names certifications by title, not by code. Its Combination Inspector route asks for ICC's Combination Inspector certification (the title of C8 on ICC's designations page) or building, electrical, plumbing and mechanical certifications. Its Limited Inspector list includes the Residential Combination Inspector certification, which is R5's title. Utah's own rules site would not load for us, so these details come from Cornell LII's copy of R156-56-302, which shows no effective date. ✓ Utah DOPL's building inspector page separately lists ICC Residential Combination Inspector as one qualifying certification for the Private Home Inspector license that took effect 1 May 2026. Confirm both against the rule DOPL links before applying.
Massachusetts was in our research plan, but its rule documents could not be retrieved today, so it is left out rather than summarized from memory.
Choosing your first exam
- Write down the job and the rule. Note the building types you will inspect and the exact state level or job posting requirement.
- Match the codes in the rule to the table above. If the rule names B1 and M1, R5 is more than you need for that job; if it names B1 and B2, plan for both.
- Pick the code year your jurisdiction expects and buy the matching book before the exam.
- Start with B1 if you are unsure. The Kentucky, Rhode Island and New Jersey rules all name it, and it is the first step toward R5, B5 and C8.
- Budget per exam. At list price, B1 alone is $320, B1 with B2 is $640 and the four R5 exams are $1,280, before books, retakes or travel.
When you have settled on B1, the free 10-question check on the ICC B1 exam page scores you by outline area so you can see where to start. It does not replace ICC's own requirements or your state's.
Sources
Show the list
- B1 Residential Building Inspector content outline, International Code Council. Retrieved 20 Oct 2026.
- B2 Commercial Building Inspector content outline, International Code Council. Retrieved 20 Oct 2026.
- ICC store listings for B1, B2, E1, M1 and P1. Retrieved 20 Oct 2026.
- Current Certification Exams: National Exams, International Code Council, last update 12 Jan 2026. Retrieved 20 Oct 2026.
- Combination Designations, International Code Council. Retrieved 20 Oct 2026.
- Exam Catalog, International Code Council. Retrieved 20 Oct 2026.
- How often can I test?, International Code Council. Retrieved 20 Oct 2026.
- 2024 study guide listings for B1, B2, E1, M1 and P1, International Code Council. Retrieved 20 Oct 2026.
- 815 KAR 7:070, Kentucky Legislative Research Commission. Retrieved 20 Oct 2026.
- 510-RICR-00-00-11, Rhode Island Secretary of State. Retrieved 20 Oct 2026.
- Mandatory exams for UCC inspector licenses and Licensing and Continuing Education, New Jersey DCA. Retrieved 20 Oct 2026.
- Utah Admin. Code R156-56-302, Cornell LII copy, and Building Inspector, Utah DOPL. Retrieved 20 Oct 2026.
Facts checked 20 October 2026 against the sources listed above. If something has changed, tell us and we will correct it within 2 business days.
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