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ICC B1 vs B2 vs R5: which inspector exam?

Rafter Tie editorial teamUpdated 8 min read

"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. The right one depends on the buildings you will inspect and the rule your state or employer applies. This page compares all three and shows what four state rules name, so you book the right exam the first time. New to the field? See how to become a building inspector for the whole route.

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.

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Public Safety and Special Construction

In a new bedroom, the only emergency escape window has a keyed sash lock, with the key hanging on a hook beside the window. What should the inspector do?

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B1, B2 and R5 side by side

B1B2R5
What it isSingle examSingle examDesignation built from four exams
ICC titleResidential Building InspectorCommercial Building InspectorResidential Combination Inspector
Scope in ICC's outlineOne- and two-family dwellings, townhomes up to three stories, accessory structuresCommercial structures of any size or occupancyBuilding, electrical, mechanical and plumbing on residential work
Questions608060 per exam, 240 in total
Time2 hours3.5 hours2 hours per exam, 8 hours in total
Code years offered2021 and 20242021 and 20242021 and 2024 for each of B1, E1, M1, P1
List price$320$320$320 per exam, $1,280 for all four

Both the B1 content outline and B2 content outline say open book. Each ICC store listing shows a $320 price. The R5 totals are four exams at list price.

Each store listing says purchases are valid for 365 days. ICC's exam catalog says members get discounted exam pricing, so this page quotes list prices. ICC's retake policy says you pay the exam fee at every attempt; the cost and scheduling guide covers ICC's attempt limits.

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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:

DesignationCertifications it requires
B5 Building InspectorB1 and B2 (ICC says it is granted automatically once you hold both)
C5 Commercial Combination InspectorB2, E2, M2, P2
C8 Combination InspectorB1, B2, E1, E2, M1, M2, P1, P2
B8 Building Code SpecialistB1, 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 areaB1 weightB2 weight
Code or general administration4%6%
Building planning8%20%
Footings and foundations16%8%
Floor construction14%8%
Wall construction and coverings27%21%
Roof and ceiling construction14%6%
Public safety and special construction17%31%

Weights are from the B1 outline and B2 outline.

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:

The exam catalog lists the references for your exam and code year, so look there 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

Each rule below is a starting point. Your jurisdiction or employer may add conditions.

StateRuleWhat it names
Kentucky815 KAR 7:070, Section 5One- 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 Island510-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 JerseyDCA required-exams sheetBuilding RCS level: B1 and M1. Building ICS level: B2 and M2. Building HHS level: B3
UtahR156-56-302(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. 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. See Cornell LII's copy of R156-56-302. 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.

Choosing your first exam

  1. Write down the job and the rule. Note the building types you will inspect and the exact state level or job posting requirement.
  2. 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.
  3. Pick the code year your jurisdiction expects and buy the matching book before the exam.
  4. 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.
  5. 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.

Want the steps done for you? The ICC exam picker takes your goal, the certifications you hold and your state, and shows the exam to start with and the exams still to take.

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FAQ

Is the ICC R5 an exam?

No. R5 Residential Combination Inspector is a designation ICC grants once you hold four residential certifications: B1, E1, M1 and P1.

What is the difference between the ICC B1 and B2?

B1 is the residential exam, covering one- and two-family dwellings, townhomes up to three stories and accessory structures, with 60 questions in 2 hours on the IRC. B2 is the commercial exam, covering commercial structures of any size or occupancy, with 80 questions in 3.5 hours on the IBC.

Should I take the B1 or the B2 first?

Take the exam your state rule or job posting names. If you are unsure, start with B1: the Kentucky, Rhode Island and New Jersey rules all name it, and it is the first step toward R5, B5 and C8.

How much do the B1, B2 and R5 exams cost?

At ICC's list price each exam is $320, so B1 with B2 is $640 and the four R5 exams are $1,280. ICC members get discounted exam pricing, and you pay the fee again at every attempt.

Sources

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