IRC chapters for the B1: what each chapter covers and where to look

This guide lists the chapters by number and title, describes each in our own words, and maps them to the seven B1 outline areas and their published weights. It gives section numbers only and never reproduces code text. Use your own IRC for the wording.

IRC chapters list: Chapters 1 to 11

The chapter numbers and titles below are the same in the 2021 and 2024 IRC, according to ICC's published contents for each edition. Section numbers inside the chapters are not always the same, and the 2021 vs 2024 guide covers what moved.

IRC code chapters list: Chapters 12 to 44

These chapters make up the rest of the book. The B1 outline names no mechanical, plumbing or electrical area, so they are low priority for this exam. Read the outline and your booking before you decide how much time to give them.

Which chapters the B1 leans on

ICC's B1 outline has seven areas. This table lines each one up with the chapters where its questions are usually answered. The weights come from the outline. The chapter mapping is our own reading of what each task describes, so check it against your book.

Three things stand out.

• Chapter 3 serves two areas. Building planning (8%) and most of public safety (17%) both send you there. Egress, stairs, smoke alarms and safety glazing are named in the public safety tasks, so up to a quarter of the exam can start in one chapter.
• Chapters 6 and 7 together are the single biggest block. Wall construction and coverings is 27%, so wall framing, headers, bracing and exterior coverings are worth your first study hours.
• Chapter 10 is small but real. The outline gives fireplaces and chimneys their own 2% task, so the fireplace and chimney sections are worth a tab.

For the full task list inside each area, read the B1 exam outline guide.

Where candidates lose time looking things up

Chapter 3 in a 2024 book. Several topics changed section numbers between editions. Smoke alarms are R314 in the 2021 IRC and R310 in the 2024 IRC, and escape openings are R310 in 2021 and R319 in 2024. A 2021 tab set in a 2024 book lands you on the wrong page. The tab list has both columns.

Walls versus coverings. Candidates open Chapter 6 for a question that lives in Chapter 7, or the reverse. Ask whether the question is about what holds the wall up (Chapter 6) or what goes on it (Chapter 7) before you flip.

Span tables. Joist, header and rafter questions end in a table, and most wrong answers come from the wrong table or the wrong column, not from a misread number. The span table method gives the inputs to gather and the order to read them in.

Chapters outside the outline. Candidates chase a plumbing or electrical question that the outline does not name. If a lookup lands in Chapters 12 to 43 and nothing in the outline points there, go back and re-read the stem.

Reading instead of finding. Chapter 3 is long. The index is often faster than paging through it, and it works for topics with no tab.

How to use this map

1. Confirm the IRC edition on your booking, then use that edition's section numbers only.
2. Put one tab on each chapter in the table above. The tab list shows where, and ICC's rules require permanently attached tabs.
3. Run timed lookups chapter by chapter, starting with the heaviest areas. The timed lookup drills give you a routine and a log. The code navigation drill times you against your own book. The B1 lookup drill runs five lookups against a target pace you set.
4. Add section tabs only where a lookup still takes over a minute.

Two worked examples

A bedroom window. A question asks whether a bedroom window works as an emergency exit. The topic is egress, which is the public safety area, so you open Chapter 3 and find the escape opening section: R310 in the 2021 IRC and R319 in the 2024 IRC. Read the conditions in your own book, then check the numbers. The egress opening check works one window through both editions.

A header over a wide opening. A question gives a header size and an opening width and asks if it works. Headers are wall construction, so you open Chapter 6 and go to R602.7, then pick the table from the wall type. That one lookup sits in the largest outline area. The span table guide shows the order to read the table in, with invented numbers.

FAQ

Do I need to read the whole IRC for the B1?

No. The outline's seven areas map to Chapters 1, 3 to 10 and a corner of 11, and the mechanical, plumbing and electrical chapters are not named in it. Spend your time on the chapters in the table above, weighted by the percentages.

Are the chapter numbers different in the 2024 IRC?

The chapter numbers and titles match the 2021 edition. The sections inside Chapter 3 moved a lot, so use the 2021 vs 2024 guide and your own book's contents.

Which chapters should I tab first?

Tab every chapter in the map, then spend your section tabs on 3, 6 and 7, the heaviest areas. Take the free check to see which of your lookups are slow.

Which chapter has the most B1 questions?

Chapters 6 and 7 together carry wall construction and coverings, the largest area at 27%. Chapter 3 serves both building planning and most of public safety, so up to a quarter of the exam can start there.

Find the chapters you are slow in

The map only helps if you can use it under a clock. Take the free 10-question check with your IRC open beside you. It is weighted to the seven outline areas, needs no signup and explains every answer, so you see which chapters cost you time. The Rafter Tie course turns the result into a study plan built from your exam date, with a lesson for each area and timed practice exams. For more routines, see the B1 study plan, the open book exam tips and the stair riser and tread check.

Sources

Show the list

• 2021 IRC contents and 2024 IRC contents, International Code Council.
• B1 Residential Building Inspector Content Outline, International Code Council.