Primary Reference

NBC 2020, National Building Code of Canada for the ExAC

The National Building Code of Canada 2020 (NBC 2020) is the model code that sets minimum building requirements across Canada. For the Examination for Architects in Canada (ExAC), NBC 2020 is one of the four primary reference documents named in the 2026 ExAC Preparation Guide, and Examitect maps it as the primary reading for every National Building Code objective in Section 2, covering code navigation through integrated code application.

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NBC 2020 overview

NBC 2020 at a glance

Full titleNational Building Code of Canada 2020
DeveloperCanadian Commission on Building and Fire Codes (CCBFC). The CCBFC was replaced by the Canadian Board for Harmonized Construction Codes (CBHCC) in November 2022; the CBHCC will oversee future editions.
PublisherNational Research Council of Canada (NRC)
Earlier editions2015, 2010, 2005, 1995, 1990, 1985 (and earlier)
LanguagesEnglish and French
Primary audienceArchitects, engineers, building officials, and anyone involved in the design, construction, or regulation of buildings in Canada
Where to accessThrough the National Research Council of Canada (NRC). Check nrc-cnrc.gc.ca for current access terms and pricing.

Why NBC 2020 matters for the ExAC

NBC 2020 is the dominant reference for ExAC Section 2. Examitect maps it as the primary reference across the National Building Code objectives in Section 2, general objectives 5.1 through 5.4, with the National Energy Code covered under 5.5. The published objectives attach no references of their own, so that mapping is ours. No other single ExAC reference carries that concentration in one section.

If you're writing Section 2, a large portion of your exam time comes down to NBC 2020 questions. Those questions test whether you can navigate the code quickly, classify a building by occupancy and size, determine which Parts apply, calculate egress requirements, apply accessibility provisions, solve spatial separation problems, and evaluate alternative solutions against the code's objectives. The exam rewards candidates who know where to look, not just what they remember.

The NBC also shapes the vocabulary of Section 2 questions. Terms like "acceptable solution," "alternative solution," "limiting distance," and "exposing building face" come straight from Division A definitions. Reading Division A carefully is not optional if you want to answer those questions correctly under time pressure.

How to study NBC 2020 for the ExAC

  • Learn the numbering system before diving into content. The format is Part.Section.Subsection.Article.(Sentence)(Clause)(Subclause), for example 3.2.3.1.(1)(a). You navigate the code under time pressure, so knowing the address system is as important as knowing the content it labels.
  • Read Division A from start to finish before opening Division B. Division A's compliance framework, definitions, and objectives govern everything in Division B. Candidates who skip Division A lose points on compliance-path and alternative-solution questions.
  • Nail the Part 3 versus Part 9 threshold: Part 9 applies to buildings three storeys or less and 600 m² or less for Groups B4, C, D, E, F2, and F3. Any building above either limit (or in a higher-risk occupancy group) moves to Part 3.
  • Drill occupancy group classification with Table 3.1.2.1. and Division A definitions until you can assign an occupancy group in seconds.
  • Study fire protection and egress from Part 3 in the order the code presents them: fire safety and construction type first (Section 3.2), then safety within floor areas (Section 3.3), then exits (Section 3.4).
  • Work through spatial separation examples. Section 3.2.3 is a reliable Section 2 exam topic; practise identifying the exposing building face, measuring the limiting distance, and determining the percentage of unprotected openings permitted.

Inside NBC 2020, the three Divisions and key Parts

The NBC is organized into three Divisions. Division B is divided into Parts, each covering a discipline or building type. Because NBC 2020 is published behind a paywall by the National Research Council, the sub-section labels below are shown as tags for orientation, not as links. Here is how the structure maps to ExAC Section 2.

Division or PartWhat it coversWhere it lands on the ExACSub-sections
NBC 2020: Division ACompliance, Objectives, Functional Statements
 The compliance framework. Defines terms, sets the two compliance paths, links each Division B provision to an objective, and establishes building size determination rules. Section 2: 5.1 (code scope and fundamentals); 5.2 (classification and applicability); 5.4 (alternative solutions).
  • Part 1: Compliance
  • Part 2: Objectives
  • Part 3: Functional Statements
  • Definitions of Terms
  • Acceptable / Alternative Solutions
NBC 2020: Part 3Fire Protection, Occupant Safety, Accessibility
 Technical requirements for larger and higher-risk buildings: fire-resistance ratings, fire separations, means of egress, occupant load, spatial separation, and barrier-free design. Section 2: 5.2 (Part 3 building standards, including fire and life safety, accessibility, and spatial separation).
  • 3.1 General
  • 3.2 Building Fire Safety
  • 3.3 Safety Within Floor Areas
  • 3.4 Exits
  • 3.5 Vertical Transportation
  • 3.6 Service Facilities
  • 3.7 Health Requirements
  • 3.8 Accessibility
NBC 2020: Part 4Structural Design
 Structural loads and procedures, including dead, live, snow, wind, seismic, and other loads. Governs how loads are determined and combined in design. Section 2: background context for structural coordination in Part 3 buildings.
  • 4.1 Loads & Effects
  • 4.2 Foundations
  • 4.3 Structural Materials: Wood, Masonry, Concrete, Steel, Aluminum, Glass
  • 4.4 Special Structures: Membrane, Parking, Storage Racks
NBC 2020: Part 5Environmental Separation
 Heat, air, vapour, and moisture control for the building envelope. The provisions most commonly tested in envelope questions. Section 2: background context for envelope questions; Part 9 envelope design is objective 5.3.4.
  • 5.1 General
  • 5.2 Loads & Procedures
  • 5.3 Heat Transfer
  • 5.4 Air Leakage
  • 5.5 Vapour Diffusion
  • 5.6 Precipitation
  • 5.7 Surface Water
  • 5.8 Sound Transmission
NBC 2020: Part 9Housing and Small Buildings
 Prescriptive requirements for buildings three storeys or less and 600 m² or less, for specified occupancies. Part 9 has its own fire protection, egress, and envelope provisions, often simpler than the Part 3 equivalents. Section 2: 5.3 (Part 9 small buildings).
  • 9.1 General
  • 9.3 Materials & Systems
  • 9.4 Structural Requirements
  • 9.5 Design of Spaces
  • 9.7 Windows, Doors, Skylights
  • 9.8 Stairs, Ramps, Guards
  • 9.9 Means of Egress
  • 9.10 Fire Protection
  • 9.25 Heat Transfer
  • 9.36 Energy Efficiency
NBC 2020: Division CAdministrative Provisions
 Rules about how the code is administered and enforced. Adopting jurisdictions frequently customize these provisions. Know it exists and what it covers. Section 2: background context for 5.1 (code scope and administration).
  • Part 1: General
  • Part 2: Administrative Provisions

If you're short on time, Division A and Part 3 carry the heaviest Section 2 exam load. Part 9 is worth a focused read for small-building questions. Parts 4 and 5 are narrower but high-yield for their specific categories.

Key NBC 2020 terms every ExAC candidate should know

The NBC's Division A definitions are precise and deliberately worded. These terms appear in ExAC questions without re-definition, so learning them from Division A is faster than guessing from everyday usage.

TermWhat it means in NBC 2020Where to read in NBC 2020
Major occupancy The principal occupancy for which a building or part is used. Table 3.1.2.1. of Division B classifies major occupancies as Groups A through F, and only Groups A, B and F carry Divisions (for example, Group F, Division 1 is high-hazard industrial); C, D and E have none. Group G agricultural occupancies are classified under Division A Article 1.3.3.6. and Part 2.
  • Division A: Definitions
  • Division B: Table 3.1.2.1.
Building height The number of storeys between the roof and the floor of the first storey. This count, not the building's metric height, determines whether Part 3 or Part 9 applies.
  • Division A: Definitions
  • Division A: Article 1.4.1.2.
  • Division A: Article 1.3.3.4.
Building area The greatest horizontal area of a building above grade, within the outer surface of exterior walls or to the centre line of firewalls. Used alongside building height to determine applicable Parts.
  • Division A: Definitions
First storey The uppermost storey having its floor level not more than two metres above grade. The starting reference for the building height calculation.
  • Division A: Definitions
Acceptable solution A Division B provision that, if followed, is deemed to satisfy the NBC objectives. The standard compliance path for the vast majority of projects.
  • Division A: Article 1.2.1.1.
  • Division A: Part 1 Compliance
Alternative solution A solution proposed in place of an acceptable solution. Must achieve at least the same level of performance as the acceptable solution it replaces, evaluated against the attributed objectives and functional statements from Division A.
  • Division A: Article 1.2.1.1.
  • Division A: Part 2 Objectives
  • Division A: Part 3 Functional Statements
Fire-resistance rating The time, in minutes or hours, that a material or assembly will withstand the passage of flame and the transmission of heat under specified fire test conditions. Expressed as a rating such as 1 h or 2 h.
  • Division A: Definitions
  • Division B: Section 3.1
  • Division B: Section 3.2
Fire-protection rating The time that a closure (door, damper, or similar element) will withstand flame passage under specified fire test conditions. Applied to closures in fire separations; distinct from the fire-resistance rating of the separation itself.
  • Division A: Definitions
  • Division B: Section 3.1
Firewall A noncombustible fire separation that subdivides a building or separates adjoining buildings. Maintains structural stability under fire conditions, allowing each portion to be treated as a separate building for code purposes.
  • Division A: Definitions
  • Division B: Subsection 3.1.10
Limiting distance The distance from an exposing building face to the nearest property line, street centre line, or imaginary line between two buildings on the same property, measured perpendicularly. The basis for all spatial separation calculations.
  • Division A: Definitions
  • Division B: Subsection 3.2.3
Exposing building face That part of the exterior wall of a building that faces one direction and is located between the ground and the ceiling of the top storey. The starting measurement in a spatial separation analysis.
  • Division A: Definitions
  • Division B: Subsection 3.2.3
Unprotected opening A doorway, window, or opening in an exposing building face that lacks a closure with the required fire-protection rating. The area of unprotected openings relative to the exposing building face area drives the spatial separation calculation.
  • Division A: Definitions
  • Division B: Subsection 3.2.3

Tips for Intern Architects reading NBC 2020

The NBC is a reference document, not a textbook. Reading it cover to cover is rarely the right strategy. Here is how to use it efficiently for the ExAC.

Tip 1, map before you memorize. Your first pass through NBC 2020 should be a structural map: table of contents, Division A headings, and the opening article of each Part. Know where major topics live before you try to memorize their content. You'll navigate the code on exam day, so the map is the first thing to build.

Tip 2, learn Division A's objective codes. The five objectives are OS (Safety), OH (Health), OA (Accessibility), OP (Fire and Structural Protection of Buildings), and OE (Environment). Alternative solution questions always reference which objectives apply. Recognizing these codes without having to look them up saves time when questions are framed around performance equivalency.

Tip 3, keep a running list of defined terms as you encounter them. The NBC's definitions are precise and deliberately different from everyday usage. Terms like "building height," "first storey," and "grade" mean exactly what Division A says they mean, and misreading any one of them can knock the whole code analysis off course. A personal glossary is worth building early.

Tip 4, practise the Part 3 / Part 9 determination with real project types. Sketch out several building scenarios (a four-storey Group C residential building, a two-storey Group E mercantile building, a Group A1 assembly hall of any size) and run the determination. Get this down to under a minute before exam day. It is the gateway to every other Section 2 code question.

Tip 5, tie code reading to live projects at your firm. When you're doing a building permit application or a code analysis at work, use the NBC as the primary tool and note which articles you use. The exam tests the same articles that come up on real projects. Work experience and study reinforce each other when you keep the code open on your desk.

Tip 6, study the model code, not your province's amendments. Provincial amendments can change specific numbers (fire-resistance ratings, ramp slopes, setback distances), but the ExAC tests the model NBC 2020. If your province deviates from the model on a specific value, set that deviation aside when answering practice questions. Study the model; apply the provincial version at work.

Common ExAC scenarios where NBC 2020 is the answer

These question types appear across ExAC Section 2 sittings. If you see one, start with the NBC and work from Division A outward.

  • A five-storey Group C residential building has a total building area of 800 m². Which Parts of Division B apply, and why?
  • A client proposes a fire barrier assembly that differs from the NBC's acceptable solutions but claims it achieves equivalent performance. What does the architect need to establish under Article 1.2.1.1. before accepting this alternative solution?
  • An architect is designing an accessible washroom in a Group D business building. What clear floor space is required for a turning circle, and which standard governs the detailed design requirements?
  • A building has an exposing building face of 120 m² and a limiting distance of 3.0 m to the property line. What percentage of unprotected openings does Section 3.2.3 permit?
  • A one-storey Group E mercantile building has a building area of 550 m². Which Part of Division B governs its fire protection requirements, and what is the threshold that places it there?
  • A client asks why the code requires a firewall rather than a standard fire separation between two portions of their building. What is the functional difference between the two?
  • Two buildings on the same property are 4.0 m apart. How is the limiting distance measured, and how does that measurement affect the spatial separation analysis for each building?

Each scenario traces back to a specific NBC article. Division A (definitions and compliance framework), Part 3 (fire, egress, accessibility, spatial separation), and Part 9 (small buildings) carry most of the Section 2 exam load.

How NBC 2020 compares to other ExAC references

Section 2 has two primary references: NBC 2020 for objectives 5.1 to 5.4, and the NECB 2020 for objective 5.5. Both sit alongside other references that ExAC candidates read for different purposes. Use this comparison to keep the references straight.

ReferenceWhat it's forHow NBC 2020 relates
NBC 2020Minimum building requirements: occupancy, fire safety, structure, accessibility, and envelope, for buildings across Canada.Named in the Preparation Guide as a primary reference document, and Examitect's reference standard for the National Building Code objectives in Section 2.
NECBEnergy efficiency requirements for all new buildings outside Part 9's scope, large residential and industrial buildings included, plus additions to them. Farm buildings are excluded.Works alongside NBC 2020 on large projects. NBC Part 9, Section 9.36 covers energy for small buildings; the NECB covers larger ones. Under the official ExAC objectives, the NECB covers the National Energy Code objective 5.5, while the National Building Code objectives are 5.1 through 5.4.
CHOPArchitectural practice management, including the code research workflow and the AHJ relationship.Different jobs. The NBC carries the provisions you must comply with; CHOP describes how to manage that compliance process. CHOP is the reference Examitect leans on for Sections 1, 3, and 4; the NBC is not. The Preparation Guide itself names both as primary reference documents for the exam without splitting them by section.
CHINGBuilding assemblies, construction systems, and detailing.CHING illustrates how assemblies are built; the NBC sets the minimum requirements those assemblies must meet. Many assemblies CHING shows are designed to achieve common NBC fire-resistance and envelope ratings.
Provincial building codesThe law in each province or territory, adopted from the model NBC with local amendments.The ExAC tests the model NBC 2020, not any province's adopted version. Be aware that amendments exist and that the adopted code governs real projects, but study the model for the exam.
RSMeans and YardsticksConstruction cost data for early-stage estimating.NBC requirements influence cost by setting minimum standards for materials and systems. The cost references give you the numbers to estimate those compliance costs.

How Examitect reinforces NBC 2020

ExAC Section 2 rewards two skills: knowing which Part of the code to go to, and then finding the right article inside that Part. Both are built through repetition. Examitect's question bank includes scenario-based questions tied to every Section 2 category, with answers that point back to specific NBC articles so you can open the code, read the provision in context, and close the loop between the question and the source.

The full bank also includes full-length mock exams that mirror ExAC pacing, and free study notes for every section. Try a few sample questions to see how NBC 2020 questions are framed, then check pricing when you're ready for the full bank.

FAQ

NBC 2020 FAQ

The National Building Code of Canada 2020 (NBC 2020) is a model code that sets minimum requirements for the design and construction of buildings across Canada. It was developed by the Canadian Commission on Building and Fire Codes (CCBFC) and published by the National Research Council of Canada (NRC). Provinces and territories adopt it with or without amendments, at which point it becomes law in that jurisdiction.

Yes. The Preparation Guide names NBC 2020 as one of four primary reference documents for the exam, and it is the code you work from for the National Building Code objectives in Section 2, covering code navigation and occupancy classification through fire safety, accessibility, spatial separation, structural coordination, and building envelope performance. The guide assigns its reference documents to the exam as a whole rather than section by section, so the section mapping here is Examitect's.

Division A establishes the compliance framework, the code's five objectives, and the functional statements that link Division B provisions to those objectives. Division B contains the acceptable solutions, the technical requirements most architects work from directly. Division C contains the administrative provisions that adopting jurisdictions frequently customize.

Part 9 applies to smaller buildings: three storeys or less and 600 m² or less, for Groups B4, C, D, E, F2, and F3. Part 3 (along with Parts 4, 5, and 6) applies to larger and higher-risk buildings, including post-disaster buildings and Group A, B, and F Division 1 occupancies of any size. Exceeding either the storey or the area threshold moves a building out of Part 9 and into Part 3.

Article 1.2.1.1. of Division A sets out two paths. The first is to follow the acceptable solutions in Division B directly. The second is to propose alternative solutions that achieve at least the same level of performance as the acceptable solutions they replace, evaluated against the objectives and functional statements attributed to those provisions in Division A.

Start by learning the numbering system (Part.Section.Subsection.Article), then read Division A fully before opening Division B. Nail the Part 3 versus Part 9 threshold. Drill occupancy group classification with Table 3.1.2.1. Study fire and egress from Part 3 in the order the code presents them, then work through spatial separation examples from Section 3.2.3.

Division A (compliance framework, definitions, objectives), Division B Part 3 (fire protection, occupant safety, accessibility, spatial separation), Part 4 (structural loads), Part 5 (environmental separation and building envelope), and Part 9 (small buildings). The Section 2 objectives themselves name Division A, Part 3, and Part 9; Parts 4 and 5 are on this list because Examitect sees them tested through the wider code-analysis objectives.

NBC 2020 covers general building requirements: occupancy, fire safety, structure, accessibility, and envelope. The National Energy Code of Canada for Buildings (NECB) sets energy efficiency requirements for all new buildings described in Sentence 1.3.3.2.(1) of NBC Division A: post-disaster buildings, Group A, B and F1 buildings of any size, and Group C, D, E, F2 and F3 buildings over 600 m2 in building area or over 3 storeys, plus additions. Farm buildings are excluded. Both appear in ExAC Section 2, but under the official ExAC objectives the NECB covers the National Energy Code objective 5.5 while the National Building Code objectives are 5.1 through 5.4.

Keep exploring

Other ExAC reference books.

NBC 2020 is one of the four primary reference documents the ExAC Preparation Guide names, alongside CHOP (2020), the IAP, and the NECB 2020. Continue with the rest of the reading list.

CHING

Building Construction Illustrated. The visual reference for assemblies, materials, and detailing across Sections 1 and 3.

CHOP

Canadian Handbook of Practice. The primary reference for Sections 1, 3, and 4; covers practice management and every project phase.

NECB

National Energy Code of Canada for Buildings. Covers the National Energy Code objective 5.5 in Section 2, alongside NBC 2020.

RSMeans

Construction cost data. Used for elemental estimating and cost-management questions in Section 1.

Yardsticks

Hanscomb Yardsticks for Costing. Canadian elemental cost data by building type and region.

Supporting references

Examitect's extended reading list of supplementary references across all four sections.