2024 code changes

Part 2 Farm Buildings: the 2024 Ontario Building Code's Newest Section

The 2024 Ontario Building Code adds a new Part 2 for farm buildings, introducing occupancy Group G with a threshold at 600 m2 and 3 storeys. This is entirely new exam territory: the BCIN exams written since March 30, 2026 can test it, and 2012-era study materials cover none of it.

What's new for farm buildings in the 2024 code?

The 2024 Ontario Building Code gives farm buildings their own dedicated Part 2, a section with no equivalent in the 2012 code. Alongside it comes a new occupancy classification, Group G, for farm buildings, with a threshold set at 600 m2 and 3 storeys. That's the headline: agricultural buildings now have a home inside the code's main structure instead of sitting at its margins.

Part 2 arrives as part of the roughly 1,730 amendments separating the 2012 and 2024 codes, documented in the Ministry of Municipal Affairs and Housing's 118-page Key Changes bulletin. For everything else that changed in the same revision, see our pillar guide to the 2024 code's 1,730 amendments.

What is Group G occupancy?

Group G is the new occupancy classification for farm buildings. Before 2024, the code's occupancy system had no farm-building classification. Group G changes that: farm buildings are now classified within the code's own occupancy structure, which is how the rest of the code decides what applies to them.

We deliberately stop there. Sub-classifications and the precise classification rules within Group G are exactly the kind of detail you should read in the 2024 Building Code Compendium itself (the primary text) or in MMAH's 2024 Building Code Technical Bulletins: Highlights of Key Changes (July 2024, PDF), not from a secondhand summary. On an open-book exam, the habit of going to the source is the habit that scores.

What does the 600 m2 / 3-storey threshold do?

The verified threshold attached to the new Group G treatment is 600 m2 and 3 storeys. Thresholds like this are how the code scales its demands: smaller, lower buildings face one set of requirements; buildings that cross the line face another. Exactly which requirements attach above and below this particular line is something to confirm in the Compendium for the building in front of you. We won't paraphrase provisions we'd tell you to look up anyway.

For exam purposes, the number itself is the anchor. Threshold values are classic multiple-choice material because they're objective, and 600 m2 / 3 storeys is a figure that didn't exist anywhere in the 2012 code.

How were farm buildings handled before 2024?

Before the 2024 edition, the Ontario Building Code had no dedicated farm-building part, and practitioners working on agricultural projects assembled requirements from other references, including farm-specific guidance published outside the Ontario code. The history is interesting, but for exam candidates it's mostly a warning: whatever reference habits you or your colleagues built on agricultural work before 2024, the exams don't test them. They test the 2024 text, where this material now lives in Part 2.

Who does the new Part 2 affect?

Three groups, mainly. Designers who take on agricultural buildings now have a code part that speaks directly to their projects. Municipal building officials and inspectors, especially in rural municipalities, need to review and enforce against provisions that didn't exist two code cycles of habit ago. And agricultural builders will see the new classification and threshold flow through into permit applications and drawings.

If you're not sure which qualification exams your role requires in the first place, start with our guide to which BCIN exams you need. Ontario has 16, and choosing precisely matters at $150 per attempt.

Why is Part 2 prime BCIN exam material?

Since March 30, 2026, all BCIN qualification exams are based on the 2024 Building Code: 70 multiple-choice questions, 3 hours, open book, 70% to pass, through Humber Polytechnic. The 2024 code includes the new Part 2, so the material is squarely inside what the exams can draw on.

Two things make it especially dangerous to skip. First, it's brand new: no 2012-era course notes, no old practice questions, no secondhand summaries cover it, because it didn't exist. Candidates leaning on older prep have a blind spot exactly here. Second, it's checkable: whether Part 2 falls inside your particular exam's scope is defined by that exam's syllabus, and MMAH publishes a free syllabus for every one of the 16 exams at ontario.ca's study-guides page. Check yours before you build a study plan, then practise finding Part 2 provisions under time pressure, because in an open-book exam the skill being scored is navigation, not recall.

FAQ

Sources: MMAH 2024 Building Code Technical Bulletins: Highlights of Key Changes (July 2024); 2024 Building Code Compendium (Publications Ontario); ontario.ca study-guide pages; Humber Polytechnic exam pages. Last reviewed 2026-08-14. Found an error? Tell us and we'll fix it.