BC Building Code Part 3 vs Part 9

Whenever a client contacts Canadian Blueprint to design a new build, secondary suite, or commercial renovation, one of the first technical checks we run is determining whether the structure falls under Part 9 or Part 3 of the BC Building Code (BCBC).

This distinction is crucial because it governs: 1. Who can draw and stamp your plans (Qualified Drafting Firm vs. Registered Architect & Certified Engineers). 2. How long municipal plan checks take (Part 9 residential sets stream through faster). 3. Construction costs & fire protection requirements (sprinkler systems, fire separations, standpipes, and exit stairs).

Under the BC Building Code, the baseline rule separating Part 9 and Part 3 comes down to three physical criteria: Building Height, Footprint Area, and Occupancy Type.

Part 9: Housing and Small Buildings

• A building qualifies under Part 9 if it satisfies ALL of the following:
• Height: 3 storeys or less in building height.
• Building Area (Footprint): 600 square metres (approx. 6,458 sq ft) or less.
• Occupancy Types Allowed:
• Group C (Residential: single-family homes, duplexes, triplexes, townhomes, secondary suites).
• Group D (Business & Personal Services: offices, beauty salons, small clinics).
• Group E (Mercantile / Retail: small shops, retail stores).
• Group F, Division 2 & 3 (Medium & Low-Hazard Industrial: small workshops, storage garages).

Part 9 Envelope Assembly

Part 3: Fire Protection, Occupant Safety & Accessibility (Complex Buildings)

• A building is classified under Part 3 if it meets ANY of the following conditions:
• Height: Exceeds 3 storeys (e.g., 4-storey wood-frame apartments or high-rises).
• Building Area: Exceeds 600 m² (6,458 sq ft) in building footprint.
• Special Occupancy Types: Automatically includes Group A (Assembly: theatres, large restaurants, churches, arenas), Group B (Care/Treatment: hospitals, nursing homes), or Group F1 (High-Hazard Industrial).

Homeowners and real estate investors often ask why renovating a townhome is different than renovating a condo unit, even if both are residential dwellings:

Townhomes (Typically Part 9)

• Most standard 2 to 3-storey townhome developments in BC are constructed under Part 9.
• Individual units are separated vertically by fire-rated demising party walls that extend from the foundation to the underside of the roof deck.
• Permit Advantage: Renovating or altering non-structural interior layout elements in a Part 9 townhome can typically be handled by a qualified drafting firm without hiring a registered Architect.

Condominiums & Apartment Buildings (Part 3)

• Condos situated in 4-storey+ wood-frame complexes, mid-rises, or concrete high-rises are classified under Part 3.
• Units are separated both vertically and horizontally by floor-ceiling assemblies and demising walls designed to strict acoustic and fire resistance ratings.
• The Catch: Altering walls, plumbing stacks, or common elements in a Part 3 condo unit requires strict compliance with Part 3 fire-stopping and structural rules. In many municipalities (like Vancouver, Surrey, or Burnaby), modifications affecting common demising walls or exterior envelopes in Part 3 buildings mandate Architect or Professional Engineer sign-off.

Under the *Architects Act* of BC and regulations enforced by the Architectural Institute of British Columbia (AIBC), you are legally required to retain a Registered Architect if your project falls into any of these categories:

1. All Part 3 Major Occupancy Buildings: Any new construction, major addition, or structural alteration to a Part 3 building (over 3 storeys or over 600 m² footprint). 2. Assembly & Care Occupancies: Buildings used for Group A (Assembly) or Group B (Care & Treatment) regardless of size (subject to minor low-occupant-load exceptions like Note A-3.1.2.6). 3. Commercial Tenant Improvements Affecting Exterior Envelopes or Fire Demising Walls: If your commercial renovation alters common fire separations or exterior building envelopes in a Part 3 multi-tenant building, an Architect or Coordinating Registered Professional (CRP) is generally required to issue Letters of Assurance (Schedule A, B, C-A, C-B).

Part 3 Commercial Fire Assembly

When Can You Use a Qualified Drafting Firm (Canadian Blueprint)?

For Part 9 residential and commercial projects—including new custom homes, duplexes, multiplexes under Bill 44 SSMUH, secondary suite legalizations, laneway houses, and small business tenant improvements—you do NOT need to pay for a registered Architect. A professional drafting firm can produce complete, permit-ready CAD/BIM drawing sets at a fraction of the cost.

Before submitting building permit plans in BC, follow this quick checklist to confirm your compliance path:

1. Measure Footprint & Count Storeys: Is your building footprint under 600 m² (6,458 sq ft) and 3 storeys or less?
2. Check Your Occupancy Group: Is your business or residence classified under Group C, D, E, or F2/F3?
3. Verify Architect & Engineering Requirements: If Part 9, engage Canadian Blueprint for cost-effective CAD/BIM permit sets. If Part 3, determine if Letters of Assurance (Schedules A, B, C) are required.

BC Building Code Scope

Explore our complete BC building code and municipal permit guide series:

• BC Building Code 2024 Free Online Access & Permit Guide →
• Commercial Lease & Building Permit Guide: Occupancy Groups →
• Step-by-Step Building Permit Design Process in BC →
• Custom Residential Design & Permit Drawings →
• Commercial Tenant Improvement Design & Permits →

Official Portals:

• Government of BC: Official 2024 BC Building Code Portal →
• Architectural Institute of BC (AIBC): When an Architect is Required →
• BC Publications Online Code Viewer →