ICC Exam Structure: B1, B2, E1, P1 & M1 — Questions, Time & Passing Scores

The Five Certifications at a Glance

All ICC inspector exams share the same DNA: open book, multiple choice, 75% to pass. Here is the full comparison:

Note: verify the exact numbers in the current official ICC exam bulletin for your certification and code edition — ICC occasionally updates formats.

B1 — Residential Building Inspector (IRC)

The entry-point certification covering one- and two-family dwellings and townhouses up to three stories. Content follows the IRC: administration, building planning, foundations, floors, walls, wall covering, roof-ceiling construction, roofing, chimneys, and energy efficiency. 60 questions in 2 hours — about 2 minutes per question.

B2 — Commercial Building Inspector (IBC)

The commercial counterpart, based on the International Building Code. B2 is the longest exam in the family: 80 questions in 3.5 hours. Content covers occupancy classification, types of construction, fire protection, means of egress, accessibility, and structural provisions.

E1 — Residential Electrical Inspector (NEC + IRC)

The E1 exam tests the National Electrical Code along with the IRC electrical chapters (Ch. 34–43). Expect questions on services, feeders, branch circuits, wiring methods, grounding and bonding, overcurrent protection, and residential electrical inspection procedures.

P1 — Residential Plumbing Inspector (IPC + IRC)

The P1 exam covers the International Plumbing Code plus the IRC plumbing chapters (Ch. 25–33): fixtures, water supply, drainage and venting, traps, and inspection of plumbing systems in residential construction.

M1 — Residential Mechanical Inspector (IMC + IRC)

The M1 exam covers the International Mechanical Code plus the IRC mechanical chapters (Ch. 12–24): heating and cooling equipment, duct systems, combustion air, venting, and fuel-gas systems in residential buildings.

How the Open-Book Format Changes Your Strategy

Every one of these exams is open book, so your preparation should be navigation-heavy: learn the chapter map of your code, drill index-first lookups, and practice with questions that cite exact sections. Read our IRC navigation guide and open-book study techniques to build that skill.

Ready to practice? Try free ICC practice questions in the real exam format.