A BCIN (Building Code Identification Number) is the number Ontario's Ministry of Municipal Affairs and Housing (MMAH) assigns to every qualified building practitioner through its QuARTS system. Designers, design firms and building officials all have one. If you prepare drawings for a building permit in Ontario and you aren't an architect or engineer, you almost certainly need one.
Who needs to be qualified
Under the Building Code Act, 1992, no one may prepare a design, or give an opinion on whether a building complies with the Building Code, for submission to a chief building official with a permit application unless they have the qualifications and meet the requirements the Building Code sets for designers. (Building Code Act, s. 15.11(5)) A "design" includes any plan, specification, sketch, drawing or graphic representation. (s. 15.11(6))
If a designer lacks the required qualifications or insurance, the chief building official must refuse the permit. (s. 8(2)(c))
Who is exempt
Architects and professional engineers licensed under the Architects Act or the Professional Engineers Act don't need a BCIN to design. (Building Code Act, s. 15.11(8))
The Building Code also exempts some design work from individual registration, including: (Div. C, 3.2.5.1.(3))
- a house you own, and its ancillary building
- a farm building of low human occupancy, not more than two storeys and under 600 m²
- an ancillary building serving a house, not more than 55 m²
- work that a qualified person will review and take responsibility for
- tents, signs, site services, pre-engineered elements and appliances
Firms have a separate, broader list of exemptions. (Div. C, 3.2.4.1.(3)–(4)) Check the exact wording before relying on one.
Firms and individual designers
There are two ways to register as a designer:
- Firms offering design to the public register under Division C, Subsection 3.2.4. That includes sole practitioners. The firm needs a qualified person for each class it holds, and it must carry professional liability insurance. (Div. C, 3.2.4.2 and 3.2.4.7)
- Other designers, such as designers who don't offer services to the public, register individually under Subsection 3.2.5. MMAH calls these "independent (other) designers". This route needs the exams but no insurance. (Div. C, 3.2.2.1 and 3.2.5)
The 12 classes of registration
Each class lets you design a particular kind of work, for the building types set out in the Code. (Div. C, Table 3.5.2.1, via 3.2.7.1)
| Class | What it covers (summary) |
|---|---|
| House | A detached house, semi-detached house or rowhouse with no more than two dwelling units, plus an ancillary building that serves it |
| Small Buildings | Part 9 buildings (3 storeys or less, building area of 600 m² or less, residential, business, mercantile or medium/low-hazard industrial), including the House scope |
| Large Buildings | Part 3 buildings: assembly, care and high-hazard buildings, and larger residential, business, mercantile and industrial buildings, plus public pools and spas |
| Complex Buildings | High buildings and buildings with interconnected floor spaces, plus the Large Buildings scope |
| Building Structural | Loadbearing structural elements (foundations, floors, walls, roofs, columns, beams) of the buildings and structures the Table refers to |
| Building Services | Fire suppression, detection, smoke control, energy efficiency, lighting and emergency power, plus HVAC systems |
| Plumbing – House / Plumbing – All Buildings | Part 7 plumbing systems: houses only, or all buildings |
| HVAC – House | Heating, ventilation and air conditioning in houses (Sections 9.32 and 9.33) |
| Detection, Lighting and Power | Fire alarm and detection, voice communication, lighting, and emergency lighting and power |
| Fire Protection | Fire suppression, detection, firefighting and fire safety systems |
| On-site Sewage Systems | Part 8 sewage systems |
A designer may do work in another class where it "does not constitute a substantial part of the design activities on any project". (Div. C, Table 3.5.2.1, Note (2)) The House definition was tightened in the April 2026 amendments, so check the current Table for the exact scope of each class.
What has to be on your drawings
Design documents submitted to a chief building official must include:
- your name and BCIN
- a statement that you have reviewed and taken responsibility for the design activities
- your signature
A firm must also include its own registered name and BCIN. (Div. C, 3.2.4.7.(1)(d) and 3.2.5.6.(1)(c))
Building officials hold BCINs too
Chief building officials, inspectors, and supervisors and managers are qualified under Division C, Section 3.1. They appear on the same public register as designers. (Div. C, 3.1.2–3.1.6)
Next: How to get your BCIN →
Sources
- Building Code Act, 1992 (e-Laws)
- Ontario Amendments to the NBC 2020, Division C Part 3 (April 2026)
- MMAH: 2024 Ontario Building Code
- MMAH: Become a registered building practitioner
Last reviewed October 2026. This page summarizes the rules for designers. It is not legal advice. Always check the current Building Code and the Ministry's guidance.
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