Updated: 31 July 2025

Class 5 Building

Overview

This article explains what Class 5 buildings are under the National Construction Code (NCC) and describes when certain professional premises may instead be classified as Class 9a health-care buildings.

Why This Is Important

  • Ensures correct building classification for compliance.
  • Helps identify when a building is Class 5 versus other classifications like Class 9a.
  • Avoids design and approval delays caused by misclassification.

What Are Class 5 Buildings?

  • Class 5 buildings are office buildings used for professional or commercial purposes.
  • They do not include Class 6, 7, 8, or 9 buildings.

Examples of Class 5 Buildings

  • Offices for:
    • Lawyers
    • Accountants
    • General medical practitioners
    • Government agencies
    • Architects

Special Consideration: Medical Practices

  • Generally, a general medical practitioner’s office is classified as a Class 5 building.
  • Exception:
    • If medical treatment administered leaves patients unconscious or non-ambulatory, the building becomes a health-care building (Class 9a) (e.g., a hospital).

Tips, Best Practices & Troubleshooting

  • Confirm the type of professional services delivered before classifying.
  • If unsure whether treatment affects a patient’s consciousness or mobility, consult the NCC definitions for health-care buildings.
  • Document classification decisions in the project file.

Building Class

Class 1 Buildings

Class 2 Buildings

Class 3 Buildings

Class 4 Buildings

Class 6 Buildings

Class 7 Buildings

Class 8 Buildings

Class 9 Buildings

Class 10 Buildings or Structures

Site Specific Engineering

Request Engineering (Site Check)

Review & Updates

Version History:

  • v1.0 – 03 September 2019
  • v2.0 – 31 July 2025

Article Information

  • Category: Engineering & Site Specifications
  • Target Audience: Franchise Users, Estimators, Sales Coordinators
  • Business Owner: 
  • Version: v2.0
  • Last Reviewed: 31 July 2025