Ontario Building Code (2024): A Plain Guide and Where to Read It Free

How the code is organized

The code has three Divisions. Knowing which one you need is the fastest way to find anything.

• Division A: Compliance, Objectives and Functional Statements. How to comply, what each Part applies to, and the definitions in Article 1.4.1.2. Italic words in the code are defined terms. The scope of Part 9 (3 storeys or less, building area not more than 600 m²) is in Div. A 1.3.3.3.OBC Div. A 1.3.3.3. Application of Part 9(1) Subject to Article 1.3.3.3B., Part 9 of Division B applies to all buildings described in Article 1.1.1.1. of 3 storeys or less in building height, having a building area not exceeding 600 m², and used for major occupancies classified as (a) reserved (b) Group C, residential occupancies other than buildings used…
• Division B: Acceptable Solutions. The technical rules, in 12 Parts: 1 General, 2 Farm Buildings, 3 Fire Protection, Occupant Safety and Accessibility, 4 Structural Design, 5 Environmental Separation, 6 Heating, Ventilating and Air-Conditioning, 7 Plumbing, 8 Sewage Systems, 9 Housing and Small Buildings, 10 Change of Use, 11 Renovation, and 12 Resource Conservation and Environmental Integrity.
• Division C: Administrative Provisions. Permits, inspections, alternative solutions, rulings, and the qualification and registration rules behind the BCIN.

The Supplementary Standards (SA-1, SB-1 to SB-13, with SB-5 reserved) sit in Volume 2 of the Compendium. They hold detail the Parts point to, such as climatic data (SB-1), fire-resistance ratings (SB-2 and SB-3), guards for housing (SB-7), soil gas control (SB-9) and energy efficiency for housing (SB-12).

Numbers follow Part, Section, Subsection, Article, then Sentence and Clause. In 9.8.8.3.(1), 9 is the Part, 9.8 the Section (stairs, ramps, handrails and guards), 9.8.8 the Subsection (guards), 9.8.8.3. the Article (height of guards) and (1) the Sentence. See it in our viewer at 9.8.8.3.OBC Div. B 9.8.8.3. Height of Guards(1) Except as provided in Sentences (2) to (3.1), all guards shall be not less than 1,070 mm high. (2) All guards within dwelling units or within houses with a secondary suite including their common spaces shall be not less than 900 mm high. (3) Exterior guards serving not more than one dwelling unit or a house with a…

Where to read the Ontario Building Code online and as a PDF

1. The digital Compendium on ontario.ca. Free HTML, searchable in your browser, maintained by the Ministry.
2. The Compendium PDFs. Publications Ontario offers Volume 1 (the Act and Divisions A, B and C) and Volume 2 (appendix notes, SA-1, SB-1 to SB-13 and SC-1) as free downloads; printed binders are sold. Open them from our code PDF page.
3. Our study viewer. The /code section lets you browse Part by Part, for example Part 9 or Section 9.8, with links from every guide on this site.
4. e-Laws. It has the Building Code Act in full, but O. Reg. 163/24 itself is now a one-page adoption of the national code. Do not expect the full code there.

Avoid code summaries written before 2025. Many still describe the 2012 code, with old article numbers and some old values. See 2024 Ontario Building Code changes.

The Building Code Act versus the Building Code

The Building Code Act, 1992 is the statute. It says no person may construct or demolish a building without a permit from the chief building official (BCA s. 8BCA s. 8 Building permits(1) No person shall construct or demolish a building or cause a building to be constructed or demolished unless a permit has been issued therefor by the chief building official. (1.1) An application for a permit to construct or demolish a building may be made by a person specified by regulation and the prescribed form…), defines what a "building" is (BCA s. 1, buildingBCA s. 1 building“building” means, (a) a structure occupying an area greater than ten square metres consisting of a wall, roof and floor or any of them or a structural system serving the function thereof including all plumbing, works, fixtures and service systems appurtenant thereto, (b) a structure occupying an area of ten square…), creates the enforcement roles and sets the penalties. The Building Code is the regulation made under the Act. It holds the technical requirements (Division B) and the administrative detail (Division C), such as which projects are exempt from permits and how fast a permit decision must be made.

In practice: the Act tells you that you need a permit, and the code tells you what the building must meet. See Do I need a building permit in Ontario?

Part 9: the part most people need

Most Ontario homes, and many small shops, offices and low-rise apartment buildings, are Part 9 buildings. Part 9 is prescriptive: span tables, footing sizes, stair dimensions and guard heights are written as numbers you can apply directly. Larger buildings, and assembly, care and high-hazard buildings, fall under Parts 3 to 6. Our Part 9 overview walks through its 41 sections.

Ontario Building Code topic guides

Each guide gives the direct answer first, our own summary table, the article numbers, and search terms that work in the code PDF.

How to look it up yourself

In the Compendium, search the article heading rather than your own words. Headings are short and appear exactly as printed, for example "Height of Guards", "Requirement for Permits", "Application of Part 9" or "Protection from Soil Gas Ingress". Once you land on the article, read every Sentence: exceptions usually sit in Sentences (2) and later. If a word is in italics, check its definition in Division A, Article 1.4.1.2.

The BCIN exam angle

The Ontario Building Code examinations (the "BCIN exams") are open book: you get the 2024 Compendium and must find answers fast. Knowing the Division and Part structure above is worth marks on every exam. Start with which BCIN exams you need, then read the free study guide for the House exam, starting with code structure, objectives and functional statements, or the Small Buildings exam. The Calculation Lab works through the numbers the exams ask for, such as stair geometry and footing sizing.